Merge pull request #57 from edx/will/studio-integration-full

Add editing view for Open Assessment block in Studio

.gitignore

@@ -30,6 +30,7 @@ pip-log.txt
 .coverage
 .tox
 nosetests.xml
+htmlcov
 
 # Translations
 *.mo

apps/openassessment/templates/openassessmentblock/oa_edit.html

+{% load i18n %}
+
+<div id="openassessment-edit">
+    <textarea class="openassessment-editor"></textarea>
+    <input type="button" class="openassessment-save-button" value="{% trans 'Save' %}"/>
+    <input type="button" class="openassessment-cancel-button" value="{% trans 'Cancel' %}"/>
+</div>

apps/openassessment/templates/openassessmentblock/oa_peer_assessment.html

@@ -54,7 +54,6 @@
 
                 <form id="peer-assessment--001__assessment" class="peer-assessment__assessment" method="post">
                     <fieldset class="assessment__fields">
-                        <legend class="assessment__instruction">{{ rubric_instructions }}</legend>
 
                         <ol class="list list--fields assessment__rubric">
                             {% for criterion in rubric_criteria %}

apps/openassessment/xblock/openassessmentblock.py

@@ -16,6 +16,7 @@ from xblock.fragment import Fragment
 from openassessment.xblock.peer_assessment_mixin import PeerAssessmentMixin
 from openassessment.xblock.self_assessment_mixin import SelfAssessmentMixin
 from openassessment.xblock.submission_mixin import SubmissionMixin
+from openassessment.xblock.studio_mixin import StudioMixin
 
 from scenario_parser import ScenarioParser
 
@@ -33,105 +34,80 @@ DEFAULT_PROMPT = """
     movies, magazines, etc., should be removed from the shelves if they are
     found offensive? Support your position with convincing arguments from your
     own experience, observations, and/or reading.
-"""
 
-DEFAULT_RUBRIC_INSTRUCTIONS = "Read for conciseness, clarity of thought, and form."
+    Read for conciseness, clarity of thought, and form.
+"""
 
 DEFAULT_RUBRIC_CRITERIA = [
     {
         'name': "Ideas",
-        'instructions': "Determine if there is a unifying theme or main idea.",
-        'total_value': 5,
+        'prompt': "Determine if there is a unifying theme or main idea.",
+        'order_num': 0,
         'options': [
-            (0, "Poor", """Difficult for the reader to discern the main idea.
-                Too brief or too repetitive to establish or maintain a focus.""",),
-            (3, "Fair", """Presents a unifying theme or main idea, but may
+            {
+                'order_num': 0, 'points': 0, 'name': 'Poor',
+                'explanation': """Difficult for the reader to discern the main idea.
+                Too brief or too repetitive to establish or maintain a focus."""
+            },
+            {
+                'order_num': 1, 'points': 3, 'name': 'Fair',
+                'explanation': """Presents a unifying theme or main idea, but may
                 include minor tangents.  Stays somewhat focused on topic and
-                task.""",),
-            (5, "Good", """Presents a unifying theme or main idea without going
-                off on tangents.  Stays completely focused on topic and task.""",),
+                task."""
+            },
+            {
+                'order_num': 2, 'points': 5, 'name': 'Good',
+                'explanation': """Presents a unifying theme or main idea without going
+                off on tangents.  Stays completely focused on topic and task."""
+            },
         ],
     },
     {
         'name': "Content",
-        'instructions': "Assess the content of the submission",
-        'total_value': 5,
+        'prompt': "Assess the content of the submission",
+        'order_num': 0,
         'options': [
-            (0, "Poor", """Includes little information with few or no details or
+            {
+                'order_num': 0, 'points': 0, 'name': 'Poor',
+                'explanation': """Includes little information with few or no details or
                 unrelated details.  Unsuccessful in attempts to explore any
-                facets of the topic.""",),
-            (1, "Fair", """Includes little information and few or no details.
-                Explores only one or two facets of the topic.""",),
-            (3, "Good", """Includes sufficient information and supporting
+                facets of the topic."""
+            },
+            {
+                'order_num': 0, 'points': 1, 'name': 'Fair',
+                'explanation': """Includes little information and few or no details.
+                Explores only one or two facets of the topic."""
+            },
+            {
+                'order_num': 0, 'points': 3, 'name': 'Good',
+                'explanation': """Includes sufficient information and supporting
                 details. (Details may not be fully developed; ideas may be
-                listed.)  Explores some facets of the topic.""",),
-            (5, "Excellent", """Includes in-depth information and exceptional
+                listed.)  Explores some facets of the topic."""
+            },
+            {
+                'order_num': 0, 'points': 3, 'name': 'Excellent',
+                'explanation': """Includes in-depth information and exceptional
                 supporting details that are fully developed.  Explores all
-                facets of the topic.""",),
-        ],
-    },
-    {
-        'name': "Organization",
-        'instructions': "Determine if the submission is well organized.",
-        'total_value': 2,
-        'options': [
-            (0, "Poor", """Ideas organized illogically, transitions weak, and
-                response difficult to follow.""",),
-            (1, "Fair", """Attempts to logically organize ideas.  Attempts to
-                progress in an order that enhances meaning, and demonstrates use
-                of transitions.""",),
-            (2, "Good", """Ideas organized logically.  Progresses in an order
-                that enhances meaning.  Includes smooth transitions.""",),
-        ],
-    },
-    {
-        'name': "Style",
-        'instructions': "Read for style.",
-        'total_value': 2,
-        'options': [
-            (0, "Poor", """Contains limited vocabulary, with many words used
-                incorrectly.  Demonstrates problems with sentence patterns.""",),
-            (1, "Fair", """Contains basic vocabulary, with words that are
-                predictable and common.  Contains mostly simple sentences
-                (although there may be an attempt at more varied sentence
-                patterns).""",),
-            (2, "Good", """Includes vocabulary to make explanations detailed and
-                precise.  Includes varied sentence patterns, including complex
-                sentences.""",),
+                facets of the topic."""
+            },
         ],
     },
-    {
-        'name': "Voice",
-        'instructions': "Read for style.",
-        'total_value': 2,
-        'options': [
-            (0, "Poor", """Demonstrates language and tone that may be
-                inappropriate to task and reader.""",),
-            (1, "Fair", """Demonstrates an attempt to adjust language and tone
-                to task and reader.""",),
-            (2, "Good", """Demonstrates effective adjustment of language and
-                tone to task and reader.""",),
-        ],
-    }
 ]
 
 UI_MODELS = {
     "submission": {
-        "assessment_type": "submission",
         "name": "submission",
         "class_id": "openassessment__response",
         "navigation_text": "Your response to this problem",
         "title": "Your Response"
     },
     "peer-assessment": {
-        "assessment_type": "peer-assessment",
         "name": "peer-assessment",
         "class_id": "openassessment__peer-assessment",
         "navigation_text": "Your assessment(s) of peer responses",
         "title": "Assess Peers' Responses"
     },
     "self-assessment": {
-        "assessment_type": "self-assessment",
         "name": "self-assessment",
         "class_id": "openassessment__self-assessment",
         "navigation_text": "Your assessment of your response",
@@ -145,7 +121,6 @@ configured. If no configuration is specified, this is the default assessment
 module(s) associated with the XBlock.
 """
 DEFAULT_PEER_ASSESSMENT = {
-    "assessment_type": "peer-assessment",
     "name": "peer-assessment",
     "start_datetime": datetime.datetime.now().isoformat(),
     "must_grade": 5,
@@ -164,7 +139,7 @@ def load(path):
     return data.decode("utf8")
 
 
-class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAssessmentMixin):
+class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAssessmentMixin, StudioMixin):
     """Displays a question and gives an area where students can compose a response."""
 
     start_datetime = String(
@@ -172,6 +147,7 @@ class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAsse
         scope=Scope.content,
         help="ISO-8601 formatted string representing the start date of this assignment."
     )
+
     due_datetime = String(
         default=None,
         scope=Scope.content,
@@ -183,31 +159,25 @@ class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAsse
         scope=Scope.content,
         help="A title to display to a student (plain text)."
     )
+
     prompt = String(
         default=DEFAULT_PROMPT,
         scope=Scope.content,
         help="A prompt to display to a student (plain text)."
     )
-    rubric = List(
-        default=[],
-        scope=Scope.content,
-        help="Instructions and criteria for students giving feedback."
-    )
-    rubric_instructions = String(
-        default=DEFAULT_RUBRIC_INSTRUCTIONS,
-        scope=Scope.content,
-        help="Instructions for self and peer assessment."
-    )
+
     rubric_criteria = List(
         default=DEFAULT_RUBRIC_CRITERIA,
         scope=Scope.content,
         help="The different parts of grading for students giving feedback."
     )
+
     rubric_assessments = List(
         default=DEFAULT_ASSESSMENT_MODULES,
         scope=Scope.content,
         help="The requested set of assessments and the order in which to apply them."
     )
+
     course_id = String(
         default=u"TestCourse",
         scope=Scope.content,
@@ -268,7 +238,6 @@ class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAsse
             "xblock_trace": trace,
             "title": self.title,
             "question": self.prompt,
-            "rubric_instructions": self.rubric_instructions,
             "rubric_criteria": self.rubric_criteria,
             "rubric_assessments": ui_models,
             "grade_state": grade_state,
@@ -293,7 +262,7 @@ class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAsse
         """
         ui_models = [UI_MODELS["submission"]]
         for assessment in self.rubric_assessments:
-            ui_model = UI_MODELS[assessment["assessment_type"]]
+            ui_model = UI_MODELS[assessment["name"]]
             ui_models.append(dict(assessment, **ui_model))
         return ui_models
 
@@ -316,23 +285,6 @@ class OpenAssessmentBlock(XBlock, SubmissionMixin, PeerAssessmentMixin, SelfAsse
             ),
         ]
 
-    @staticmethod
-    def studio_view(context=None):
-        """Determines how the XBlock is rendered for editing in Studio.
-
-        Displays the section where Editing can occur within Studio to modify
-        this XBlock instance.
-
-        Args:
-            context: Not actively used for this view.
-
-        Returns:
-            (Fragment): An HTML fragment for editing the configuration of this
-                XBlock.
-
-        """
-        return Fragment(u"<div>Edit the XBlock.</div>")
-
     @classmethod
     def parse_xml(cls, node, runtime, keys, id_generator):
         """Instantiate XBlock object from runtime XML definition.

apps/openassessment/xblock/peer_assessment_mixin.py

@@ -72,7 +72,6 @@ class PeerAssessmentMixin(object):
             peer_sub = self.get_peer_submission(self.get_student_item_dict(), assessment)
             context_dict = {
                 "peer_submission": peer_sub,
-                "rubric_instructions": self.rubric_instructions,
                 "rubric_criteria": self.rubric_criteria
             }
         return self.render_assessment('openassessmentblock/oa_peer_assessment.html', context_dict)

apps/openassessment/xblock/scenario_parser.py

@@ -69,7 +69,7 @@ class ScenarioParser(object):
                 )
             rubric_criteria.append(crit)
 
-        return (e.text.strip(), rubric_criteria)
+        return rubric_criteria
 
     def get_assessments(self, assessments):
         """<assessments>
@@ -113,8 +113,7 @@ class ScenarioParser(object):
             if child.tag == 'prompt':
                 self.xblock.prompt = self.get_prompt(child)
             elif child.tag == 'rubric':
-                (self.xblock.rubric_instructions, 
-                 self.xblock.rubric_criteria) = self.get_rubric(child)
+                 self.xblock.rubric_criteria = self.get_rubric(child)
             elif child.tag == 'title':
                 self.xblock.title = self.get_title(child)
             elif child.tag == 'assessments':

apps/openassessment/xblock/static/js/src/oa_edit.js

+/* JavaScript for Studio editing view of Open Assessment XBlock */
+function OpenAssessmentBlock(runtime, element) {
+
+    function displayError(errorMsg) {
+        runtime.notify('error', {msg: errorMsg});
+    }
+
+    // Update editor with the XBlock's current content
+    function updateEditorFromXBlock(editor) {
+        $.ajax({
+            type: "POST",
+            url: runtime.handlerUrl(element, 'xml'),
+            data: "\"\"",
+            success: function(data) {
+                if (data.success) {
+                    editor.setValue(data.xml);
+                }
+
+                else {
+                    displayError(data.msg);
+                }
+            }
+        });
+    }
+
+    function initializeEditor() {
+        var textAreas = $(element).find('.openassessment-editor');
+        if (textAreas.length < 1) {
+            console.warn("Could not find element for OpenAssessmentBlock XML editor");
+            return null;
+        }
+        else {
+            return CodeMirror.fromTextArea(
+                textAreas[0], {mode: "xml", lineNumbers: true, lineWrapping: true}
+            );
+        }
+    }
+
+    function initializeSaveButton(editor) {
+        saveButtons = $(element).find('.openassessment-save-button');
+        if (saveButtons.length < 1) {
+            console.warn("Could not find element for OpenAssessmentBlock save button");
+        }
+        else {
+            saveButtons.click(function (eventObject) {
+                // Notify the client-side runtime that we are starting
+                // to save so it can show the "Saving..." notification
+                runtime.notify('save', {state: 'start'});
+
+                // POST the updated description to the XBlock
+                // The server-side code is responsible for validating and persisting
+                // the updated content.
+                $.ajax({
+                    type: "POST",
+                    url: runtime.handlerUrl(element, 'update_xml'),
+                    data: JSON.stringify({ xml: editor.getValue() }),
+                    success: function(data) {
+                        // Notify the client-side runtime that we finished saving
+                        // so it can hide the "Saving..." notification.
+                        if (data.success) {
+                            runtime.notify('save', {state: 'end'});
+                        }
+
+                        // Display an error alert if any errors occurred
+                        else {
+                            displayError(data.msg);
+                        }
+                    }
+                });
+            });
+        }
+    }
+
+    function initializeCancelButton(editor) {
+        cancelButtons = $(element).find('.openassessment-cancel-button');
+        if (cancelButtons.length < 1) {
+            console.warn("Could not find element for OpenAssessmentBlock cancel button");
+        }
+        else {
+            cancelButtons.click(function (eventObject) {
+                // Revert to the XBlock's current content
+                updateEditorFromXBlock(editor);
+
+                // Notify the client-side runtime so it will close the editing modal.
+                runtime.notify('cancel', {});
+            });
+        }
+    }
+
+    $(function ($) {
+        editor = initializeEditor();
+        if (editor) {
+            updateEditorFromXBlock(editor);
+            initializeSaveButton(editor);
+            initializeCancelButton(editor);
+        }
+    });
+}

apps/openassessment/xblock/studio_mixin.py

+"""
+Studio editing view for OpenAssessment XBlock.
+"""
+import pkg_resources
+import logging
+import dateutil.parser
+from django.template.context import Context
+from django.template.loader import get_template
+from django.utils.translation import ugettext as _
+from xblock.core import XBlock
+from xblock.fragment import Fragment
+from openassessment.xblock.xml import (
+    serialize_content, update_from_xml,
+    UpdateFromXmlError, InvalidRubricError
+)
+from openassessment.peer.serializers import (
+    rubric_from_dict, AssessmentSerializer, InvalidRubric
+)
+
+
+logger = logging.getLogger(__name__)
+
+
+class StudioMixin(object):
+    """
+    Studio editing view for OpenAssessment XBlock.
+    """
+
+    def studio_view(self, context=None):
+        """
+        Render the OpenAssessment XBlock for editing in Studio.
+
+        Args:
+            context: Not actively used for this view.
+
+        Returns:
+            (Fragment): An HTML fragment for editing the configuration of this XBlock.
+        """
+        rendered_template = get_template('openassessmentblock/oa_edit.html').render(Context({}))
+        frag = Fragment(rendered_template)
+        frag.add_javascript(pkg_resources.resource_string(__name__, "static/js/src/oa_edit.js"))
+        frag.initialize_js('OpenAssessmentBlock')
+        return frag
+
+    @XBlock.json_handler
+    def update_xml(self, data, suffix=''):
+        """
+        Update the XBlock's XML.
+
+        Args:
+            data (dict): Data from the request; should have a value for the key 'xml'
+                containing the XML for this XBlock.
+
+        Kwargs:
+            suffix (str): Not used
+
+        Returns:
+            dict with keys 'success' (bool) and 'msg' (str)
+        """
+        if 'xml' in data:
+            try:
+                update_from_xml(
+                    self, data['xml'],
+                    rubric_validator=self._validate_rubric,
+                    assessment_validator=self._validate_assessment
+                )
+
+            except InvalidRubricError:
+                return {'success': False, 'msg': _('Rubric definition was not valid.')}
+
+            except UpdateFromXmlError as ex:
+                return {'success': False, 'msg': _('An error occurred while saving: {error}').format(error=ex.message)}
+
+            else:
+                return {'success': True, 'msg': _('Successfully updated OpenAssessment XBlock')}
+
+        else:
+            return {'success': False, 'msg': _('Must specify "xml" in request JSON dict.')}
+
+    @XBlock.json_handler
+    def xml(self, data, suffix=''):
+        """
+        Retrieve the XBlock's content definition, serialized as XML.
+
+        Args:
+            data (dict): Not used
+
+        Kwargs:
+            suffix (str): Not used
+
+        Returns:
+            dict with keys 'success' (bool), 'message' (unicode), and 'xml' (unicode)
+        """
+        try:
+            xml = serialize_content(self)
+
+        # We do not expect `serialize_content` to raise an exception,
+        # but if it does, handle it gracefully.
+        except Exception as ex:
+            msg = _('An unexpected error occurred while loading the problem: {error}').format(error=ex.message)
+            logger.error(msg)
+            return {'success': False, 'msg': msg, 'xml': u''}
+        else:
+            return {'success': True, 'msg': '', 'xml': xml}
+
+    def _validate_rubric(self, rubric_dict):
+        """
+        Check that the rubric is semantically valid.
+
+        Args:
+            rubric_dict (dict): Serialized Rubric model from the peer grading app.
+
+        Returns:
+            boolean indicating whether the rubric is semantically valid.
+        """
+        try:
+            rubric_from_dict(rubric_dict)
+        except InvalidRubric as ex:
+            return (False, ex.message)
+        else:
+            return (True, u'')
+
+    def _validate_assessment(self, assessment_dict):
+        """
+        Check that the assessment is semantically valid.
+
+        Args:
+            assessment (dict): Serialized Assessment model from the peer grading app.
+
+        Returns:
+            boolean indicating whether the assessment is semantically valid.
+        """
+        # Supported assessment
+        if not assessment_dict.get('name') in ['peer-assessment', 'self-assessment']:
+            return (False, _("Assessment type is not supported"))
+
+        # Number you need to grade is >= the number of people that need to grade you
+        if assessment_dict.get('must_grade') < assessment_dict.get('must_be_graded_by'):
+            return (False, _('"must_grade" should be less than "must_be_graded_by"'))
+
+        # Due date is after start date, if both are specified.
+        start_datetime = assessment_dict.get('start_datetime')
+        due_datetime = assessment_dict.get('due_datetime')
+
+        if start_datetime is not None and due_datetime is not None:
+            start = dateutil.parser.parse(assessment_dict.get('start_datetime'))
+            due = dateutil.parser.parse(assessment_dict.get('due_datetime'))
+
+            if start > due:
+                return (False, _('Due date must be after start date'))
+
+        return (True, u'')

apps/openassessment/xblock/submission_mixin.py

@@ -156,7 +156,6 @@ class SubmissionMixin(object):
                 assessment_ui_model["must_be_graded_by"]
             )
             context["peer_assessments"] = assessments
-            context["rubric_instructions"] = self.rubric_instructions
             context["rubric_criteria"] = self.rubric_criteria
             for criterion in context["rubric_criteria"]:
                 criterion["median_score"] = median_scores[criterion["name"]]

apps/openassessment/xblock/test/data/serialize.json

+{
+    "simple": {
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            },
+            {
+                "name": "self-assessment",
+                "start_datetime": "2014-04-01T00:00:00",
+                "due_datetime": "2014-06-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ],
+        "expected_xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+                "<assessment name=\"self-assessment\" start=\"2014-04-01T00:00:00\" due=\"2014-06-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "unicode": {
+        "title": "ƒσσ",
+        "prompt": "Ṫëṡẗ ṗṛöṁṗẗ",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "ՇﻉรՇ ƈɼٱՇﻉɼٱѻก",
+                "prompt": "TɘꙅT ↄᴙiTɘᴙioᴎ qᴙomqT",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "ℕ𝕠",
+                        "explanation": "ℕ𝕠 𝕖𝕩𝕡𝕝𝕒𝕟𝕒𝕥𝕚𝕠𝕟"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Чэѕ",
+                        "explanation": "Чэѕ эхрlаиатіои"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ],
+        "expected_xml": [
+            "<openassessmentblock>",
+            "<title>ƒσσ</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Ṫëṡẗ ṗṛöṁṗẗ</prompt>",
+                "<criterion>",
+                    "<name>ՇﻉรՇ ƈɼٱՇﻉɼٱѻก</name>",
+                    "<prompt>TɘꙅT ↄᴙiTɘᴙioᴎ qᴙomqT</prompt>",
+                    "<option points=\"0\"><name>ℕ𝕠</name><explanation>ℕ𝕠 𝕖𝕩𝕡𝕝𝕒𝕟𝕒𝕥𝕚𝕠𝕟</explanation></option>",
+                    "<option points=\"2\"><name>Чэѕ</name><explanation>Чэѕ эхрlаиатіои</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "reverse_option_order": {
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 2,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 0,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-06-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ],
+        "expected_xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-06-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "reverse_criteria_order": {
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 2,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 2,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            },
+            {
+                "order_num": 1,
+                "name": "Second criterion",
+                "prompt": "Second criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 1,
+                        "name": "Maybe",
+                        "explanation": "Maybe explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-06-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ],
+        "expected_xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-06-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Second criterion</name>",
+                    "<prompt>Second criterion prompt</prompt>",
+                    "<option points=\"1\"><name>Maybe</name><explanation>Maybe explanation</explanation></option>",
+                "</criterion>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "default_dates": {
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": null,
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            },
+            {
+                "name": "self-assessment",
+                "start_datetime": "2014-04-01T00:00:00",
+                "due_datetime": null,
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ],
+        "expected_xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+                "<assessment name=\"self-assessment\" start=\"2014-04-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    }
+}

apps/openassessment/xblock/test/data/update_from_xml.json

+{
+    "simple": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+                "<assessment name=\"self-assessment\" start=\"2014-04-01T00:00:00\" due=\"2014-06-01T00:00:00\" must_grade=\"2\" must_be_graded_by=\"1\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ],
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            },
+            {
+                "name": "self-assessment",
+                "start_datetime": "2014-04-01T00:00:00",
+                "due_datetime": "2014-06-01T00:00:00",
+                "must_grade": 2,
+                "must_be_graded_by": 1
+            }
+        ]
+    },
+
+    "unicode": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>िѻѻ</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>ՇєรՇ קг๏๓קՇ</prompt>",
+                "<criterion>",
+                    "<name>𝓣𝓮𝓼𝓽 𝓬𝓻𝓲𝓽𝓮𝓻𝓲𝓸𝓷</name>",
+                    "<prompt>Ŧɇsŧ ȼɍɨŧɇɍɨøn ꝑɍømꝑŧ</prompt>",
+                    "<option points=\"0\"><name>𝕹𝖔</name><explanation>𝕹𝖔 𝖊𝖝𝖕𝖑𝖆𝖓𝖆𝖙𝖎𝖔𝖓</explanation></option>",
+                    "<option points=\"2\"><name>ﻉร</name><explanation>ﻉร ﻉซρɭคกคՇٱѻก</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ],
+        "title": "िѻѻ",
+        "prompt": "ՇєรՇ קг๏๓קՇ",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "𝓣𝓮𝓼𝓽 𝓬𝓻𝓲𝓽𝓮𝓻𝓲𝓸𝓷",
+                "prompt": "Ŧɇsŧ ȼɍɨŧɇɍɨøn ꝑɍømꝑŧ",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "𝕹𝖔",
+                        "explanation": "𝕹𝖔 𝖊𝖝𝖕𝖑𝖆𝖓𝖆𝖙𝖎𝖔𝖓"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "ﻉร",
+                        "explanation": "ﻉร ﻉซρɭคกคՇٱѻก"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ]
+    },
+
+    "multiple_criteria": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+                "<criterion>",
+                    "<name>Second criterion</name>",
+                    "<prompt>Second criterion prompt</prompt>",
+                    "<option points=\"1\"><name>Maybe</name><explanation>Maybe explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ],
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            },
+            {
+                "order_num": 1,
+                "name": "Second criterion",
+                "prompt": "Second criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 1,
+                        "name": "Maybe",
+                        "explanation": "Maybe explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": "2014-02-27T09:46:28",
+                "due_datetime": "2014-03-01T00:00:00",
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ]
+    },
+
+    "no_dates_specified": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"0\"><name>No</name><explanation>No explanation</explanation></option>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ],
+        "title": "Foo",
+        "prompt": "Test prompt",
+        "criteria": [
+            {
+                "order_num": 0,
+                "name": "Test criterion",
+                "prompt": "Test criterion prompt",
+                "options": [
+                    {
+                        "order_num": 0,
+                        "points": 0,
+                        "name": "No",
+                        "explanation": "No explanation"
+                    },
+                    {
+                        "order_num": 1,
+                        "points": 2,
+                        "name": "Yes",
+                        "explanation": "Yes explanation"
+                    }
+                ]
+            }
+        ],
+        "assessments": [
+            {
+                "name": "peer-assessment",
+                "start_datetime": null,
+                "due_datetime": null,
+                "must_grade": 5,
+                "must_be_graded_by": 3
+            }
+        ]
+    }
+
+}

apps/openassessment/xblock/test/data/update_from_xml_error.json

+{
+    "empty_string": {"xml": [""]},
+
+    "invalid_syntax": {"xml": ["<openassessmentblock><div>no closing tag</openassessmentblock>"]},
+
+    "missing_root": {"xml": "<div>Incorrect</div>"},
+
+    "missing_assessment_name": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "missing_title": {
+        "xml": [
+            "<openassessmentblock>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "missing_rubric": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "missing_assessments": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"2\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "non_numeric_points": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"5\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"non-numeric\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "non_numeric_must_grade": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"non-numeric\" must_be_graded_by=\"3\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"5\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "non_numeric_must_be_graded_by": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-02-27T09:46:28\" due=\"2014-03-01T00:00:00\" must_grade=\"2\" must_be_graded_by=\"non-numeric\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"5\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "invalid_start_date": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"non-date\" due=\"2014-03-01T00:00:00\" must_grade=\"2\" must_be_graded_by=\"5\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"5\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    },
+
+    "invalid_due_date": {
+        "xml": [
+            "<openassessmentblock>",
+            "<title>Foo</title>",
+            "<assessments>",
+                "<assessment name=\"peer-assessment\" start=\"2014-03-01T00:00:00\" due=\"non-date\" must_grade=\"2\" must_be_graded_by=\"5\" />",
+            "</assessments>",
+            "<rubric>",
+                "<prompt>Test prompt</prompt>",
+                "<criterion>",
+                    "<name>Test criterion</name>",
+                    "<prompt>Test criterion prompt</prompt>",
+                    "<option points=\"5\"><name>Yes</name><explanation>Yes explanation</explanation></option>",
+                "</criterion>",
+            "</rubric>",
+            "</openassessmentblock>"
+        ]
+    }
+}

apps/openassessment/xblock/test/test_openassessment.py

@@ -53,7 +53,7 @@ RUBRIC_CONFIG = """
               due="2014-12-21T22:22"
               must_grade="5"
               must_be_graded_by="3" />
-            <self-assessment/>
+            <self-assessment name="self-assessment"/>
         </assessments>
     </openassessment>
 """

apps/openassessment/xblock/test/test_scenario_parser.py

@@ -43,10 +43,9 @@ class TestScenarioParser(TestCase):
                                cit=criterion_prompt_text,
                                coet=criterion_option_explain_text)
         rubric_xml = etree.fromstring(rubric_text)
-        rubric_prompt, rubric_criteria = self.test_parser.get_rubric(rubric_xml)
+        rubric_criteria = self.test_parser.get_rubric(rubric_xml)
 
         # Basic shape of the rubric: prompt and criteria
-        self.assertEqual(rubric_prompt, rubric_prompt_text)
         self.assertEqual(len(rubric_criteria), 1)
 
         # Look inside the criterion to make sure it's shaped correctly

apps/openassessment/xblock/test/test_xml.py

+"""
+Tests for serializing to/from XML.
+"""
+import copy
+import mock
+import lxml.etree as etree
+from django.test import TestCase
+from ddt import ddt, data, file_data, unpack
+from openassessment.xblock.openassessmentblock import OpenAssessmentBlock, UI_MODELS
+from openassessment.xblock.xml import (
+    serialize_content, update_from_xml,
+    UpdateFromXmlError, InvalidRubricError, InvalidAssessmentError
+)
+
+
+@ddt
+class TestSerializeContent(TestCase):
+    """
+    Test serialization of OpenAssessment XBlock content to XML.
+    """
+    BASIC_CRITERIA = [
+        {
+            "order_num": 0,
+            "name": "Test criterion",
+            "prompt": "Test criterion prompt",
+            "options": [
+                {
+                    "order_num": 0,
+                    "points": 0,
+                    "name": "Maybe",
+                    "explanation": "Maybe explanation"
+                }
+            ]
+        }
+    ]
+
+    BASIC_ASSESSMENTS = [
+        {
+            "name": "peer-assessment",
+            "start_datetime": "2014-02-27T09:46:28.873926",
+            "due_datetime": "2014-05-30T00:00:00.92926",
+            "must_grade": 5,
+            "must_be_graded_by": 3,
+        },
+        {
+            "name": "self-assessment",
+            "start_datetime": '2014-04-01T00:00:00.000000',
+            "due_datetime": "2014-06-01T00:00:00.92926",
+            "must_grade": 5,
+            "must_be_graded_by": 3,
+        }
+    ]
+
+    def setUp(self):
+        """
+        Mock the OA XBlock.
+        """
+        self.oa_block = mock.MagicMock(OpenAssessmentBlock)
+
+    @file_data('data/serialize.json')
+    def test_serialize(self, data):
+        self.oa_block.title = data['title']
+        self.oa_block.prompt = data['prompt']
+        self.oa_block.rubric_criteria = data['criteria']
+        self.oa_block.rubric_assessments = data['assessments']
+        xml = serialize_content(self.oa_block)
+
+        # Compare the XML with our expected output
+        # To make the comparison robust, first parse the actual and expected XML
+        # then compare elements/attributes in the tree.
+        try:
+            parsed_actual = etree.fromstring(xml)
+        except (ValueError, etree.XMLSyntaxError):
+            self.fail("Could not parse output XML:\n{}".format(xml))
+
+        # Assume that the test data XML is valid; if not, this will raise an error
+        # instead of a test failure.
+        parsed_expected = etree.fromstring("".join(data['expected_xml']))
+
+        # Pretty-print and reparse the expected XML
+        pretty_expected = etree.tostring(parsed_expected, pretty_print=True, encoding='utf-8')
+        parsed_expected = etree.fromstring(pretty_expected)
+
+
+        # Walk both trees, comparing elements and attributes
+        actual_elements = [el for el in parsed_actual.getiterator()]
+        expected_elements = [el for el in parsed_expected.getiterator()]
+
+        self.assertEqual(
+            len(actual_elements), len(expected_elements),
+            msg="Incorrect XML output:\nActual: {}\nExpected: {}".format(actual_elements, expected_elements)
+        )
+
+        for actual, expected in zip(actual_elements, expected_elements):
+            self.assertEqual(actual.tag, expected.tag)
+            self.assertEqual(
+                actual.text, expected.text,
+                msg="Incorrect text for {tag}".format(tag=actual.tag)
+            )
+            self.assertItemsEqual(
+                actual.items(), expected.items(),
+                msg="Incorrect attributes for {tag}".format(tag=actual.tag)
+            )
+
+    def test_mutated_criteria_dict(self):
+        self.oa_block.title = "Test title"
+        self.oa_block.rubric_assessments = self.BASIC_ASSESSMENTS
+
+        # We have to be really permissive with the data we'll accept.
+        # If the data we're retrieving is somehow corrupted,
+        # Studio authors should still be able to retrive an XML representation
+        # so they can edit and fix the issue.
+        # To test this, we systematically mutate a valid rubric dictionary by
+        # mutating the dictionary, then asserting that we can parse the generated XML.
+        for criteria_dict in self.BASIC_CRITERIA:
+            for mutated_dict in self._dict_mutations(criteria_dict):
+                self.oa_block.rubric_criteria = mutated_dict
+                xml = serialize_content(self.oa_block)
+
+                try:
+                    etree.fromstring(xml)
+                except Exception as ex:
+                    msg = "Could not parse mutated criteria dict {criteria}\n{ex}".format(criteria=mutated_dict, ex=ex)
+                    self.fail(msg)
+
+    def test_mutated_assessments_dict(self):
+        self.oa_block.title = "Test title"
+        self.oa_block.rubric_criteria = self.BASIC_CRITERIA
+
+        for assessment_dict in self.BASIC_ASSESSMENTS:
+            for mutated_dict in self._dict_mutations(assessment_dict):
+                self.oa_block.rubric_assessments = [mutated_dict]
+                xml = serialize_content(self.oa_block)
+
+                try:
+                    etree.fromstring(xml)
+                except Exception as ex:
+                    msg = "Could not parse mutated assessment dict {assessment}\n{ex}".format(assessment=mutated_dict, ex=ex)
+                    self.fail(msg)
+
+    @data("title", "prompt")
+    def test_mutated_field(self, field):
+        self.oa_block.rubric_criteria = self.BASIC_CRITERIA
+        self.oa_block.rubric_assessments = self.BASIC_ASSESSMENTS
+
+        for mutated_value in [0, u"\u9282", None]:
+            setattr(self.oa_block, 'title', mutated_value)
+            xml = serialize_content(self.oa_block)
+
+            try:
+                etree.fromstring(xml)
+            except Exception as ex:
+                msg = "Could not parse mutated field {field} with value {value}\n{ex}".format(
+                    field=field, value=mutated_value, ex=ex
+                )
+                self.fail(msg)
+
+    def _dict_mutations(self, input_dict):
+        """
+        Iterator over mutations of a dictionary:
+        1) Remove keys
+        2) Empty lists/dictionaries
+        3) Change value to None
+        4) Change value to unicode
+        5) Change value to an integer
+
+        Args:
+            input_dict (dict): A JSON-serializable dictionary to traverse.
+
+        Yields:
+            dict
+        """
+        for key, val in input_dict.iteritems():
+
+            # Mutation #1: Remove the key
+            print "== Removing key {}".format(key)
+            yield {k:v for k,v in input_dict.iteritems() if k != key}
+
+            if isinstance(val, dict):
+
+                # Mutation #2: Empty dict
+                print "== Emptying dict {}".format(key)
+                yield self._mutate_dict(input_dict, key, dict())
+
+                # Mutation #3-5: value mutations
+                for mutated in self._value_mutations(input_dict, key):
+                    yield mutated
+
+                # Recursively mutate sub keys
+                for sub_mutation in self._dict_mutations(val):
+                    yield self._mutate_dict(input_dict, key, sub_mutation)
+
+            elif isinstance(val, list):
+                # Mutation #2: Empty list
+                print "== Emptying list {}".format(key)
+                yield self._mutate_dict(input_dict, key, list())
+
+                # Mutation #3-5: value mutations
+                for mutated in self._value_mutations(input_dict, key):
+                    yield mutated
+
+                # Recursively mutate sub-items
+                for item in val:
+                    if isinstance(item, dict):
+                        for sub_mutation in self._dict_mutations(item):
+                            yield self._mutate_dict(input_dict, key, sub_mutation)
+
+            else:
+                # Mutation #3-5: value mutations
+                for mutated in self._value_mutations(input_dict, key):
+                    yield mutated
+
+    def _value_mutations(self, input_dict, key):
+        """
+        Iterate over mutations of the value for `key` in a dictionary.
+
+        Args:
+            input_dict (dict): The dictionary to mutate.
+            key (str): The key whose value will be mutated.
+
+        Yields:
+            dict
+        """
+        print "== None value {}".format(key)
+        yield self._mutate_dict(input_dict, key, None)
+
+        print "== Unicode value {}".format(key)
+        yield self._mutate_dict(input_dict, key, u"\u9731")
+
+        print "== int value {}".format(key)
+        yield self._mutate_dict(input_dict, key, 0)
+
+    def _mutate_dict(self, input_dict, key, new_val):
+        """
+        Copy and update a dictionary.
+
+        Args:
+            input_dict (dict): The dictionary to copy and update.
+            key (str): The key of the value to update.
+            new_val: The new value to set for the key
+
+        Returns:
+            A copy of the dictionary with the value for `key` set to `new_val`.
+        """
+        mutated = copy.deepcopy(input_dict)
+        mutated[key] = new_val
+        return mutated
+
+@ddt
+class TestUpdateFromXml(TestCase):
+    """
+    Test deserialization of OpenAssessment XBlock content from XML.
+    """
+    maxDiff = None
+
+    def setUp(self):
+        """
+        Mock the OA XBlock.
+        """
+        self.oa_block = mock.MagicMock(OpenAssessmentBlock)
+        self.oa_block.title = ""
+        self.oa_block.prompt = ""
+        self.oa_block.rubric_criteria = dict()
+        self.oa_block.rubric_assessments = list()
+
+    @file_data('data/update_from_xml.json')
+    def test_update_from_xml(self, data):
+
+        # Update the block based on the fixture XML definition
+        returned_block = update_from_xml(self.oa_block, "".join(data['xml']))
+
+        # The block we passed in should be updated and returned
+        self.assertEqual(self.oa_block, returned_block)
+
+        # Check that the contents of the modified XBlock are correct
+        self.assertEqual(self.oa_block.title, data['title'])
+        self.assertEqual(self.oa_block.prompt, data['prompt'])
+        self.assertEqual(self.oa_block.rubric_criteria, data['criteria'])
+        self.assertEqual(self.oa_block.rubric_assessments, data['assessments'])
+
+    @file_data('data/update_from_xml_error.json')
+    def test_update_from_xml_error(self, data):
+        with self.assertRaises(UpdateFromXmlError):
+            update_from_xml(self.oa_block, "".join(data['xml']))
+
+    @file_data('data/update_from_xml.json')
+    def test_invalid_rubric(self, data):
+        # Plug in a rubric validator that always reports that the rubric dict is invalid.
+        # We need to back this up with an integration test that checks whether the XBlock
+        # provides an appropriate rubric validator.
+        with self.assertRaises(InvalidRubricError):
+            update_from_xml(
+                self.oa_block, "".join(data['xml']),
+                rubric_validator=lambda _: (False, '')
+            )
+
+    @file_data('data/update_from_xml.json')
+    def test_invalid_assessment(self, data):
+        # Plug in an assessment validator that always reports that the assessment dict is invalid.
+        with self.assertRaises(InvalidAssessmentError):
+            update_from_xml(
+                self.oa_block, "".join(data['xml']),
+                assessment_validator=lambda _: (False, '')
+            )

apps/openassessment/xblock/xml.py

+"""
+Serialize and deserialize OpenAssessment XBlock content to/from XML.
+"""
+import lxml.etree as etree
+import dateutil.parser
+import defusedxml.ElementTree as safe_etree
+from django.utils.translation import ugettext as _
+
+
+class UpdateFromXmlError(Exception):
+    """
+    Error occurred while deserializing the OpenAssessment XBlock content from XML.
+    """
+    pass
+
+
+class InvalidRubricError(UpdateFromXmlError):
+    """
+    The rubric definition is semantically invalid.
+    """
+    pass
+
+
+class InvalidAssessmentError(UpdateFromXmlError):
+    """
+    The assessment definition is semantically invalid.
+    """
+    pass
+
+
+def _sort_by_order_num(items):
+    """
+    Sort dictionaries by the key "order_num".
+    If no order number is specified, assign an arbitrary order.
+    Ignores non-dict items in the list.
+
+    Args:
+        items (list): List of dictionaries to sort.
+
+    Returns:
+        dict
+    """
+    return sorted([
+            el for el in items
+            if isinstance(el, dict)
+        ], key=lambda el: el.get('order_num', 0)
+    )
+
+
+def _safe_get_text(element):
+    """
+    Retrieve the text from the element, safely handling empty elements.
+
+    Args:
+        element (lxml.etree.Element): The XML element.
+
+    Returns:
+        unicode
+    """
+    return unicode(element.text) if element.text is not None else u""
+
+
+def _serialize_options(options_root, options_list):
+    """
+    Serialize rubric criterion options as XML, adding children to the XML
+    with root node `options_root`.
+
+    We don't make any assumptions about the contents of `options_list`,
+    and we handle unexpected inputs gracefully.
+
+    Args:
+        options_root (lxml.etree.Element): The root node of the tree.
+        options_list (list): List of options dictionaries.
+
+    Returns:
+        None
+    """
+    # Sort the options by order number, then serialize as XML
+    for option in _sort_by_order_num(options_list):
+        option_el = etree.SubElement(options_root, 'option')
+
+        # Points (default to 0)
+        option_el.set('points', unicode(option.get('points', 0)))
+
+        # Name (default to empty str)
+        option_name = etree.SubElement(option_el, 'name')
+        option_name.text = unicode(option.get('name', u''))
+
+        # Explanation (default to empty str)
+        option_explanation = etree.SubElement(option_el, 'explanation')
+        option_explanation.text = unicode(option.get('explanation', u''))
+
+
+def _serialize_criteria(criteria_root, criteria_list):
+    """
+    Serialize rubric criteria as XML, adding children to the XML
+    with root node `criteria_root`.
+
+    We don't make any assumptions about the contents of `criteria_list`,
+    and we handle unexpected inputs gracefully.
+
+    Args:
+        critera_root (lxml.etree.Element): The root node of the tree.
+        criteria_list (list): List of criteria dictionaries.
+
+    Returns:
+        None
+    """
+
+    # Sort the criteria by order number, then serialize as XML
+    for criterion in _sort_by_order_num(criteria_list):
+        criterion_el = etree.SubElement(criteria_root, 'criterion')
+
+        # Criterion name (default to empty string)
+        criterion_name = etree.SubElement(criterion_el, u'name')
+        criterion_name.text = unicode(criterion.get('name', ''))
+
+        # Criterion prompt (default to empty string)
+        criterion_prompt = etree.SubElement(criterion_el, 'prompt')
+        criterion_prompt.text = unicode(criterion.get('prompt', u''))
+
+        # Criterion options
+        options_list = criterion.get('options', None)
+        if isinstance(options_list, list):
+            _serialize_options(criterion_el, options_list)
+
+
+def _serialize_rubric(rubric_root, oa_block):
+    """
+    Serialize a rubric dictionary as XML, adding children to the XML
+    with root node `rubric_root`.
+
+    This is very liberal in what it accepts.  If the rubric dict persisted
+    by the XBlock is invalid for some reason, we still want to generate XML
+    so that Studio authors can fix the error.
+
+    Args:
+        oa_block (OpenAssessmentBlock): The OpenAssessmentBlock to serialize
+        rubric_dict (dict): A dictionary representation of the rubric, of the form
+            described in the serialized Rubric model (peer grading serializers).
+
+    Returns:
+        None
+    """
+    # Rubric prompt (default to empty text)
+    prompt = etree.SubElement(rubric_root, 'prompt')
+    prompt.text = unicode(oa_block.prompt)
+
+    # Criteria
+    criteria_list = oa_block.rubric_criteria
+
+    if isinstance(criteria_list, list):
+        _serialize_criteria(rubric_root, criteria_list)
+
+
+def _parse_date(date_str):
+    """
+    Attempt to parse a date string into ISO format (without milliseconds)
+    Returns `None` if this cannot be done.
+
+    Args:
+        date_str (str): The date string to parse.
+
+    Returns:
+        unicode in ISO format (without milliseconds) if the date string is parseable
+        None if parsing fails.
+    """
+    try:
+        # Get the date into ISO format
+        parsed_date = dateutil.parser.parse(unicode(date_str))
+        formatted_date = parsed_date.strftime("%Y-%m-%dT%H:%M:%S")
+        return unicode(formatted_date)
+    except (TypeError, ValueError):
+        return None
+
+
+def _parse_options_xml(options_root):
+    """
+    Parse <options> element in the OpenAssessment XBlock's content XML.
+
+    Args:
+        options_root (lxml.etree.Element): The root of the tree.
+
+    Returns:
+        list of option dictionaries, as defined in the Rubric model of the peer grading app.
+
+    Raises:
+        UpdateFromXmlError: The XML definition is invalid or the XBlock could not be updated.
+    """
+    options_list = []
+    order_num = 0
+
+    for option in options_root.findall('option'):
+        option_dict = dict()
+
+        # Option order number (sequential)
+        option_dict['order_num'] = order_num
+        order_num += 1
+
+        # Option points -- must be an integer!
+        if 'points' in option.attrib:
+            try:
+                option_dict['points'] = int(option.get('points'))
+            except ValueError:
+                raise UpdateFromXmlError(_("XML option points must be an integer."))
+        else:
+            raise UpdateFromXmlError(_("XML option definition must contain a 'points' attribute."))
+
+        # Option name
+        option_name = option.find('name')
+        if option_name is not None:
+            option_dict['name'] = _safe_get_text(option_name)
+        else:
+            raise UpdateFromXmlError(_("XML option definition must contain a <name> element."))
+
+        # Option explanation
+        option_explanation = option.find('explanation')
+        if option_explanation is not None:
+            option_dict['explanation'] = _safe_get_text(option_explanation)
+        else:
+            raise UpdateFromXmlError(_("XML option definition must contain an <explanation> element."))
+
+        # Add the options dictionary to the list
+        options_list.append(option_dict)
+
+    return options_list
+
+
+def _parse_criteria_xml(criteria_root):
+    """
+    Parse <criteria> element in the OpenAssessment XBlock's content XML.
+
+    Args:
+        criteria_root (lxml.etree.Element): The root node of the tree.
+
+    Returns:
+        list of criteria dictionaries, as defined in the Rubric model of the peer grading app.
+
+    Raises:
+        UpdateFromXmlError: The XML definition is invalid or the XBlock could not be updated.
+    """
+    criteria_list = []
+    order_num = 0
+
+    for criterion in criteria_root.findall('criterion'):
+        criterion_dict = dict()
+
+        # Criterion order number (sequential)
+        criterion_dict['order_num'] = order_num
+        order_num += 1
+
+        # Criterion name
+        criterion_name = criterion.find('name')
+        if criterion_name is not None:
+            criterion_dict['name'] = _safe_get_text(criterion_name)
+        else:
+            raise UpdateFromXmlError(_("XML criterion definition must contain a <name> element."))
+
+        # Criterion prompt
+        criterion_prompt = criterion.find('prompt')
+        if criterion_prompt is not None:
+            criterion_dict['prompt'] = _safe_get_text(criterion_prompt)
+        else:
+            raise UpdateFromXmlError(_("XML criterion definition must contain a <prompt> element."))
+
+        # Criterion options
+        criterion_dict['options'] = _parse_options_xml(criterion)
+
+        # Add the newly constructed criterion dict to the list
+        criteria_list.append(criterion_dict)
+
+    return criteria_list
+
+
+def _parse_rubric_xml(rubric_root, validator):
+    """
+    Parse <rubric> element in the OpenAssessment XBlock's content XML.
+
+    Args:
+        rubric_root (lxml.etree.Element): The root of the <rubric> node in the tree.
+        validator (callable): Function that accepts a rubric dict and returns
+            a boolean indicating whether the rubric is semantically valid
+            and an error message string.
+
+    Returns:
+        dict, a serialized representation of a rubric, as defined by the peer grading serializers.
+
+    Raises:
+        UpdateFromXmlError: The XML definition is invalid or the XBlock could not be updated.
+        InvalidRubricError: The rubric was not semantically valid.
+    """
+    rubric_dict = dict()
+
+    # Rubric prompt
+    prompt_el = rubric_root.find('prompt')
+    if prompt_el is not None:
+        rubric_dict['prompt'] = _safe_get_text(prompt_el)
+    else:
+        raise UpdateFromXmlError(_("XML rubric definition must contain a <prompt> element."))
+
+    # Criteria
+    rubric_dict['criteria'] = _parse_criteria_xml(rubric_root)
+
+    # Validate the rubric
+    success, msg = validator(rubric_dict)
+    if not success:
+        raise InvalidRubricError(msg)
+
+    return rubric_dict
+
+
+def _parse_assessments_xml(assessments_root, validator):
+    """
+    Parse the <assessments> element in the OpenAssessment XBlock's content XML.
+
+    Args:
+        assessments_root (lxml.etree.Element): The root of the <assessments> node in the tree.
+        validator (callable): Function that accepts an assessment dict and returns
+            a boolean indicating whether the assessment is semantically valid
+            and an error message.
+
+    Returns:
+        list of assessment dicts
+
+    Raises:
+        InvalidAssessmentError: Assessment definition was not semantically valid.
+    """
+    assessments_list = []
+
+    for assessment in assessments_root.findall('assessment'):
+
+        assessment_dict = dict()
+
+        # Assessment name
+        if 'name' in assessment.attrib:
+            assessment_dict['name'] = unicode(assessment.get('name'))
+        else:
+            raise UpdateFromXmlError(_('XML assessment definition must have a "name" attribute'))
+
+        # Assessment start
+        if 'start' in assessment.attrib:
+            parsed_start = _parse_date(assessment.get('start'))
+            if parsed_start is not None:
+                assessment_dict['start_datetime'] = parsed_start
+            else:
+                raise UpdateFromXmlError(_("Could not parse 'start' attribute as a valid date time"))
+        else:
+            # If no start is specified, default to None, meaning always open
+            assessment_dict['start_datetime'] = None
+
+        # Assessment due
+        if 'due' in assessment.attrib:
+            parsed_start = _parse_date(assessment.get('due'))
+            if parsed_start is not None:
+                assessment_dict['due_datetime'] = parsed_start
+            else:
+                raise UpdateFromXmlError(_("Could not parse 'due' attribute as a valid date time"))
+        else:
+            # If no due date is specified, default to None, meaning never due
+            assessment_dict['due_datetime'] = None
+
+        # Assessment must_grade
+        if 'must_grade' in assessment.attrib:
+            try:
+                assessment_dict['must_grade'] = int(assessment.get('must_grade'))
+            except ValueError:
+                raise UpdateFromXmlError(_('Assessment "must_grade" attribute must be an integer.'))
+        else:
+            raise UpdateFromXmlError(_('XML assessment definition must have a "must_grade" attribute'))
+
+        # Assessment must_be_graded_by
+        if 'must_be_graded_by' in assessment.attrib:
+            try:
+                assessment_dict['must_be_graded_by'] = int(assessment.get('must_be_graded_by'))
+            except ValueError:
+                raise UpdateFromXmlError(_('Assessment "must_be_graded_by" attribute must be an integer.'))
+        else:
+            raise UpdateFromXmlError(_('XML assessment definition must have a "must_be_graded_by" attribute'))
+
+        # Validate the semantics of the assessment definition
+        success, msg = validator(assessment_dict)
+        if not success:
+            raise InvalidAssessmentError(msg)
+
+        assessments_list.append(assessment_dict)
+
+    return assessments_list
+
+
+def serialize_content(oa_block):
+    """
+    Serialize the OpenAssessment XBlock's content to XML.
+
+    Args:
+        oa_block (OpenAssessmentBlock): The open assessment block to serialize.
+
+    Returns:
+        xml (unicode)
+    """
+    root = etree.Element('openassessmentblock')
+
+    # Open assessment displayed title
+    title = etree.SubElement(root, 'title')
+    title.text = unicode(oa_block.title)
+
+    # Assessment list
+    assessments_root = etree.SubElement(root, 'assessments')
+    for assessment_dict in oa_block.rubric_assessments:
+
+        assessment = etree.SubElement(assessments_root, 'assessment')
+
+        # Set assessment attributes, defaulting to empty values
+        assessment.set('name', unicode(assessment_dict.get('name', '')))
+        assessment.set('must_grade', unicode(assessment_dict.get('must_grade', '')))
+        assessment.set('must_be_graded_by', unicode(assessment_dict.get('must_be_graded_by', '')))
+
+        # Start and due dates default to None, indicating always open / never closed respectively
+        start_datetime = assessment_dict.get('start_datetime')
+        due_datetime = assessment_dict.get('due_datetime')
+
+        if start_datetime is not None:
+            assessment.set('start', unicode(start_datetime))
+
+        if due_datetime is not None:
+            assessment.set('due', unicode(due_datetime))
+
+    # Rubric
+    rubric_root = etree.SubElement(root, 'rubric')
+    _serialize_rubric(rubric_root, oa_block)
+
+    # Return a UTF-8 representation of the XML
+    return etree.tostring(root, pretty_print=True, encoding='utf-8')
+
+
+def update_from_xml(
+    oa_block, xml,
+    rubric_validator=lambda _: (True, ''),
+    assessment_validator=lambda _: (True, '')
+):
+    """
+    Update the OpenAssessment XBlock's content from an XML definition.
+
+    We need to be strict about the XML we accept, to avoid setting
+    the XBlock to an invalid state (which will then be persisted).
+
+    Args:
+        oa_block (OpenAssessmentBlock): The open assessment block to update.
+        xml (unicode): The XML definition of the XBlock's content.
+
+    Kwargs:
+        rubric_validator (callable): Function that accepts a rubric dict and returns
+            a boolean indicating whether the rubric is semantically valid and an error message.
+            The default implementation performs no validation.
+        assessment_validator (callable): Function that accepts an assessment dict and returns
+            a boolean indicating whether the assessment is semantically valid and an error message.
+            The default implementation performs no validation.
+
+    Returns:
+        OpenAssessmentBlock
+
+    Raises:
+        UpdateFromXmlError: The XML definition is invalid or the XBlock could not be updated.
+        InvalidRubricError: The rubric was not semantically valid.
+    """
+    # Parse the XML content definition
+    # Use the defusedxml library implementation to avoid known security vulnerabilities in ElementTree:
+    # http://docs.python.org/2/library/xml.html#xml-vulnerabilities
+    try:
+        root = safe_etree.fromstring(xml.encode('utf-8'))
+    except (ValueError, safe_etree.ParseError) as ex:
+        raise UpdateFromXmlError(_("An error occurred while parsing the XML content."))
+
+    # Check that the root has the correct tag
+    if root.tag != 'openassessmentblock':
+        raise UpdateFromXmlError(_("XML content must contain an <openassessmentblock> root element."))
+
+    # Retrieve the title
+    title_el = root.find('title')
+    if title_el is None:
+        raise UpdateFromXmlError(_("XML content must contain a <title> element."))
+    else:
+        title = _safe_get_text(title_el)
+
+    # Retrieve the rubric
+    rubric_el = root.find('rubric')
+    if rubric_el is None:
+        raise UpdateFromXmlError(_("XML content must contain a <rubric> element."))
+    else:
+        rubric = _parse_rubric_xml(rubric_el, rubric_validator)
+
+    # Retrieve the assessments
+    assessments_el = root.find('assessments')
+    if assessments_el is None:
+        raise UpdateFromXmlError(_("XML content must contain an <assessments> element."))
+    else:
+        assessments = _parse_assessments_xml(assessments_el, assessment_validator)
+
+    # If we've gotten this far, then we've successfully parsed the XML
+    # and validated the contents.  At long last, we can safely update the XBlock.
+    oa_block.title = title
+    oa_block.prompt = rubric['prompt']
+    oa_block.rubric_criteria = rubric['criteria']
+    oa_block.rubric_assessments = assessments
+
+    return oa_block

requirements/base.txt

@@ -3,6 +3,7 @@ git+https://github.com/edx/XBlock.git@923978c5#egg=XBlock
 git+https://github.com/ormsbee/xblock-sdk.git@295678ff#egg=xblock-sdk
 
 # Third Party Requirements
+defusedxml==0.4.1
 django==1.4.8
 django-extensions==1.2.5
 djangorestframework==2.3.5

requirements/test.txt

 # Grab everything in base requirements
 -r base.txt
 
-ddt==0.4.0
+ddt==0.7.0
 django-nose==1.2
 mock==1.0.1
 nose==1.3.0