Adding the functionality for Remove Submission from grading pool.

TNL-900

openassessment/assessment/api/peer.py

@@ -12,12 +12,12 @@ from dogapi import dog_stats_api
 from openassessment.assessment.models import (
     Assessment, AssessmentFeedback, AssessmentPart,
     InvalidRubricSelection, PeerWorkflow, PeerWorkflowItem,
-)
+    PeerWorkflowCancellation)
 from openassessment.assessment.serializers import (
     AssessmentFeedbackSerializer, RubricSerializer,
     full_assessment_dict, rubric_from_dict, serialize_assessments,
-    InvalidRubric
-)
+    InvalidRubric,
+    PeerWorkflowCancellationSerializer)
 from openassessment.assessment.errors import (
     PeerAssessmentRequestError, PeerAssessmentWorkflowError, PeerAssessmentInternalError
 )
@@ -945,3 +945,54 @@ def _log_workflow(submission_uuid, workflow):
     tags.append(u"overgrading")
 
     dog_stats_api.increment('openassessment.assessment.peer_workflow.count', tags=tags)
+
+
+def cancel_submission_peer_workflow(submission_uuid, comments, cancelled_by_id):
+    """
+    Add an entry in PeerWorkflowCancellation table for a PeerWorkflow.
+
+    PeerWorkflow which has been cancelled are no longer included in the
+    peer grading pool.
+
+    Args:
+        submission_uuid (str): The UUID of the peer workflow.
+        comments: The reason for cancellation.
+        cancelled_by_id: The ID of the user who cancelled the peer workflow.
+    """
+    try:
+        workflow = PeerWorkflow.objects.get(submission_uuid=submission_uuid)
+        return PeerWorkflowCancellation.create(workflow=workflow, comments=comments, cancelled_by_id=cancelled_by_id)
+    except (
+        PeerWorkflow.DoesNotExist,
+        PeerWorkflow.MultipleObjectsReturned,
+    ):
+        error_message = u"Error finding workflow for submission UUID {}.".format(submission_uuid)
+        logger.exception(error_message)
+        raise PeerAssessmentWorkflowError(error_message)
+    except DatabaseError:
+        error_message = u"Error creating peer workflow cancellation for submission UUID {}.".format(submission_uuid)
+        logger.exception(error_message)
+        raise PeerAssessmentInternalError(error_message)
+
+
+def get_submission_cancellation(submission_uuid):
+    """
+    Get cancellation information for a submission's peer workflow.
+
+    Args:
+        submission_uuid (str): The UUID of the peer workflow.
+    """
+    try:
+        workflow = PeerWorkflow.objects.get(submission_uuid=submission_uuid)
+        workflow_cancellation = workflow.cancellation.get()
+        return PeerWorkflowCancellationSerializer(workflow_cancellation).data
+    except (
+        PeerWorkflow.DoesNotExist,
+        PeerWorkflowCancellation.DoesNotExist,
+        PeerWorkflowCancellation.MultipleObjectsReturned
+    ):
+        return None
+    except DatabaseError:
+        error_message = u"Error finding peer workflow cancellation for submission UUID {}.".format(submission_uuid)
+        logger.exception(error_message)
+        raise PeerAssessmentInternalError(error_message)
\ No newline at end of file

openassessment/assessment/models/peer.py

@@ -206,7 +206,8 @@ class PeerWorkflow(models.Model):
 
         Before retrieving a new submission for a peer assessor, check to see if that
         assessor already has a submission out for assessment. If an unfinished
-        assessment is found that has not expired, return the associated submission.
+        assessment is found that has not expired or has not been cancelled,
+        return the associated submission.
 
         TODO: If a user begins an assessment, then resubmits, this will never find
         the unfinished assessment. Is this OK?
@@ -221,13 +222,12 @@ class PeerWorkflow(models.Model):
 
         """
         oldest_acceptable = now() - self.TIME_LIMIT
-        items = list(self.graded.all().order_by("-started_at", "-id"))
+        items = list(self.graded.all().select_related('author').order_by("-started_at", "-id"))
         valid_open_items = []
         completed_sub_uuids = []
-
         # First, remove all completed items.
         for item in items:
-            if item.assessment is not None:
+            if item.assessment is not None or item.author.cancellation.exists():
                 completed_sub_uuids.append(item.submission_uuid)
             else:
                 valid_open_items.append(item)
@@ -266,6 +266,7 @@ class PeerWorkflow(models.Model):
         #  3) Is not something you have already scored.
         #  4) Does not have a combination of completed assessments or open
         #     assessments equal to or more than the requirement.
+        #  5) Has not been cancelled.
         try:
             peer_workflows = list(PeerWorkflow.objects.raw(
                 "select pw.id, pw.submission_uuid "
@@ -274,6 +275,11 @@ class PeerWorkflow(models.Model):
                 "and pw.course_id=%s "
                 "and pw.student_id<>%s "
                 "and pw.grading_completed_at is NULL "
+                "and ("
+                "   select count(pwc.id)"
+                "   from assessment_peerworkflowcancellation pwc"
+                "   where pwc.workflow_id=pw.id"
+                ") = 0 "
                 "and pw.id not in ("
                 "   select pwi.author_id "
                 "   from assessment_peerworkflowitem pwi "
@@ -318,6 +324,7 @@ class PeerWorkflow(models.Model):
         # that:
         #  1) Does not belong to you
         #  2) Is not something you have already scored
+        #  3) Has not been cancelled.
         try:
             query = list(PeerWorkflow.objects.raw(
                 "select pw.id, pw.submission_uuid "
@@ -325,6 +332,11 @@ class PeerWorkflow(models.Model):
                 "where course_id=%s "
                 "and item_id=%s "
                 "and student_id<>%s "
+                "and ("
+                "   select count(pwc.id)"
+                "   from assessment_peerworkflowcancellation pwc"
+                "   where pwc.workflow_id=pw.id"
+                ") = 0 "
                 "and pw.id not in ( "
                     "select pwi.author_id "
                     "from assessment_peerworkflowitem pwi "
@@ -461,3 +473,51 @@ class PeerWorkflowItem(models.Model):
 
     def __unicode__(self):
         return repr(self)
+
+
+class PeerWorkflowCancellation(models.Model):
+    """Model for tracking cancellations of peer workflows.
+
+    It is created when a staff member requests removal of a submission
+    from the peer grading pool.
+    """
+    workflow = models.ForeignKey(PeerWorkflow, related_name='cancellation')
+    comments = models.TextField(max_length=10000)
+    cancelled_by_id = models.CharField(max_length=40, db_index=True)
+
+    created_at = models.DateTimeField(default=now, db_index=True)
+
+    class Meta:
+        ordering = ["created_at", "id"]
+        app_label = "assessment"
+
+    def __repr__(self):
+        return (
+            "PeerWorkflowCancellation(workflow={0.workflow}, "
+            "comments={0.comments}, cancelled_by_id={0.cancelled_by_id}, "
+            "created_at={0.created_at})"
+        ).format(self)
+
+    def __unicode__(self):
+        return repr(self)
+
+    @classmethod
+    def create(cls, workflow, comments, cancelled_by_id):
+        """
+        Create a new PeerWorkflowCancellation object.
+
+        Args:
+            workflow (PeerWorkflow): The cancelled peer workflow.
+            comments (unicode): The reason for cancellation.
+            cancelled_by_id (unicode): The ID of the user who cancelled the peer workflow.
+
+        Returns:
+            PeerWorkflowCancellation
+
+        """
+        workflow_params = {
+            'workflow': workflow,
+            'comments': comments,
+            'cancelled_by_id': cancelled_by_id,
+        }
+        return cls.objects.create(**workflow_params)

openassessment/assessment/serializers/peer.py

@@ -5,8 +5,8 @@ from rest_framework import serializers
 from .base import AssessmentSerializer
 from openassessment.assessment.models import (
     AssessmentFeedback, AssessmentFeedbackOption,
-    PeerWorkflow, PeerWorkflowItem
-)
+    PeerWorkflow, PeerWorkflowItem,
+    PeerWorkflowCancellation)
 
 
 class AssessmentFeedbackOptionSerializer(serializers.ModelSerializer):
@@ -71,3 +71,17 @@ class PeerWorkflowItemSerializer(serializers.ModelSerializer):
             'assessment',
             'scored'
         )
+
+
+class PeerWorkflowCancellationSerializer(serializers.ModelSerializer):
+    """
+    Serialize a `PeerWorkflowCancellation` model.
+    """
+
+    class Meta:
+        model = PeerWorkflowCancellation
+        fields = (
+            'comments',
+            'cancelled_by_id',
+            'created_at',
+        )

openassessment/assessment/test/test_peer.py

@@ -13,7 +13,7 @@ from openassessment.test_utils import CacheResetTest
 from openassessment.assessment.api import peer as peer_api
 from openassessment.assessment.models import (
     Assessment, AssessmentPart, AssessmentFeedback, AssessmentFeedbackOption,
-    PeerWorkflow, PeerWorkflowItem
+    PeerWorkflow, PeerWorkflowCancellation, PeerWorkflowItem
 )
 from openassessment.workflow import api as workflow_api
 from submissions import api as sub_api
@@ -151,7 +151,7 @@ class TestPeerApi(CacheResetTest):
     Tests for the peer assessment API functions.
     """
 
-    CREATE_ASSESSMENT_NUM_QUERIES = 58
+    CREATE_ASSESSMENT_NUM_QUERIES = 59
 
     def test_create_assessment_points(self):
         self._create_student_and_submission("Tim", "Tim's answer")
@@ -882,6 +882,15 @@ class TestPeerApi(CacheResetTest):
         item = buffy_workflow.find_active_assessments()
         self.assertEqual(xander_answer["uuid"], item.submission_uuid)
 
+        # Cancel the Xander's submission.
+        xander_workflow = PeerWorkflow.get_by_submission_uuid(xander_answer['uuid'])
+        PeerWorkflowCancellation.create(workflow=xander_workflow, comments='test comments', cancelled_by_id=_['student_id'])
+
+        # Check to see if Buffy is actively reviewing Xander's submission.
+        # She isn't able to get the submission to assess.
+        item = buffy_workflow.find_active_assessments()
+        self.assertIsNone(item)
+
     def test_get_workflow_by_uuid(self):
         buffy_answer, _ = self._create_student_and_submission("Buffy", "Buffy's answer")
         self._create_student_and_submission("Xander", "Xander's answer")
@@ -903,6 +912,16 @@ class TestPeerApi(CacheResetTest):
         submission_uuid = buffy_workflow.get_submission_for_review(3)
         self.assertEqual(xander_answer["uuid"], submission_uuid)
 
+        # Cancel the Xander's submission.
+        xander_workflow = PeerWorkflow.get_by_submission_uuid(xander_answer['uuid'])
+        PeerWorkflowCancellation.create(workflow=xander_workflow, comments='test comments',
+                                        cancelled_by_id=_['student_id'])
+
+        # Check to see if Buffy is actively reviewing Xander's submission.
+        # She isn't able to get the submission uuid to assess.
+        submission_uuid = buffy_workflow.get_submission_for_review(3)
+        self.assertNotEqual(xander_answer["uuid"], submission_uuid)
+
     def test_get_submission_for_over_grading(self):
         buffy_answer, _ = self._create_student_and_submission("Buffy", "Buffy's answer")
         xander_answer, _ = self._create_student_and_submission("Xander", "Xander's answer")

openassessment/templates/openassessmentblock/staff_debug/student_info.html

@@ -11,7 +11,17 @@
             <div class="step__content">
                 <h3 class="title">{% trans "Student Response" %}</h3>
                 <div class="student__answer__display__content">
-                    {{ submission.answer.text|linebreaks }}
+                    {% if submission_cancellation %}
+                        {% blocktrans with removed_by_username=submission_cancellation.cancelled_by removed_datetime=submission_cancellation.created_at|utc|date:"N j, Y H:i e" %}
+                            Student submission removed by {{ removed_by_username }} on {{ removed_datetime }}
+                        {% endblocktrans %}
+                        <br>
+                        {% blocktrans with comments=submission_cancellation.comments %}
+                            Comments: {{ comments }}
+                        {% endblocktrans %}
+                    {% else %}
+                        {{ submission.answer.text|linebreaks }}
+                    {% endif %}
                 </div>
 
                 {% if submission.image_url %}
@@ -24,6 +34,60 @@
             </div>
         </div>
 
+        {% if not submission_cancellation %}
+        <div id="openassessment__staff-info__cancel__submission"
+             class="openassessment__staff-info__cancel__submission wrapper--staff-info wrapper--ui-staff wrapper--ui--collapse">
+            <div class="ui-staff ui-toggle-visibility is--collapsed">
+                <h2 class="staff-info__title ui-staff__title ui-toggle-visibility__control">
+                    <i class="ico icon-caret-right"></i>
+                    <span class="staff-info__collapse__title">{% trans "Remove submission from peer grading" %}</span>
+                </h2>
+
+                <div class="staff-info__cancel-submission__content ui-toggle-visibility__content">
+                    <div class="ui-staff__content__section">
+                        <div class="wrapper--input">
+
+                            <form id="openassessment_staff_cancel_submission_form"
+                                  data-submission-uuid="{{ submission.uuid }}">
+
+                                <ul class="list list--actions">
+                                    <li>
+                                        <div class="has--warnings">
+                                            <div class="warning">
+                                                {% trans "Caution: Removing a student's submission is irreversible. It should only be used in cases where the student's submission was inappropriate." %}
+                                            </div>
+                                        </div>
+                                    </li>
+                                    <li>
+                                        <label for="staff-info__cancel-submission__comments"
+                                               class="label">{% trans "Comments:" %}</label>
+                                    </li>
+                                    <li>
+                                        <textarea
+                                                id="staff-info__cancel-submission__comments"
+                                                class="cancel_submission_comments"
+                                                value=""
+                                                maxlength="10000"></textarea>
+                                    </li>
+                                </ul>
+                                <ul class="list list--actions">
+                                    <li class="list--actions__item">
+                                        <a data-submission-uuid="{{ submission.uuid }}" aria-role="button" href=""
+                                           id="submit_cancel_submission" class="action--submit is--disabled">
+                                            <span class="copy">{% trans "Remove submission" %}</span>
+                                        </a>
+
+                                        <div class="cancel-submission-error"></div>
+                                    </li>
+                                </ul>
+                            </form>
+                        </div>
+                    </div>
+                </div>
+            </div>
+        </div>
+        {% endif %}
+
         {% if peer_assessments %}
         <div class="staff-info__status ui-staff__content__section">
             <h3 class="title">{% trans "Peer Assessments for This Student" %}</h3>
@@ -64,7 +128,7 @@
                 {% endwith %}
             {%  endfor %}
         </div>
-            {% endif %}
+        {% endif %}
 
         {% if submitted_assessments %}
         <div class="staff-info__status ui-staff__content__section">

openassessment/xblock/openassessmentblock.py

@@ -211,7 +211,6 @@ class OpenAssessmentBlock(
         """
 
         item_id = self._serialize_opaque_key(self.scope_ids.usage_id)
-
         # This is not the real way course_ids should work, but this is a
         # temporary expediency for LMS integration
         if hasattr(self, "xmodule_runtime"):
@@ -746,3 +745,7 @@ class OpenAssessmentBlock(
             return key.to_deprecated_string()
         else:
             return unicode(key)
+
+    def get_username(self, anonymous_user_id):
+        if hasattr(self, "xmodule_runtime"):
+            return self.xmodule_runtime.get_real_user(anonymous_user_id).username

openassessment/xblock/staff_info_mixin.py

@@ -7,6 +7,9 @@ from functools import wraps
 import logging
 
 from xblock.core import XBlock
+from openassessment.assessment.errors import (
+    PeerAssessmentInternalError, PeerAssessmentWorkflowError,
+)
 from openassessment.assessment.errors.ai import AIError
 from openassessment.xblock.resolve_dates import DISTANT_PAST, DISTANT_FUTURE
 from openassessment.xblock.data_conversion import (
@@ -35,7 +38,7 @@ def require_global_admin(error_key):
         Decorated function
 
     """
-    def _decorator(func):   # pylint: disable=C0111
+    def _decorator(func):  # pylint: disable=C0111
         @wraps(func)
         def _wrapped(xblock, *args, **kwargs):  # pylint: disable=C0111
             permission_errors = {
@@ -86,7 +89,7 @@ class StaffInfoMixin(object):
 
     @XBlock.handler
     @require_course_staff("STAFF_INFO")
-    def render_staff_info(self, data, suffix=''):   # pylint: disable=W0613
+    def render_staff_info(self, data, suffix=''):  # pylint: disable=W0613
         """
         Template context dictionary for course staff debug panel.
 
@@ -158,7 +161,7 @@ class StaffInfoMixin(object):
 
     @XBlock.json_handler
     @require_global_admin("SCHEDULE_TRAINING")
-    def schedule_training(self, data, suffix=''):   # pylint: disable=W0613
+    def schedule_training(self, data, suffix=''):  # pylint: disable=W0613
         """
         Schedule a new training task for example-based grading.
         """
@@ -194,7 +197,7 @@ class StaffInfoMixin(object):
 
     @XBlock.handler
     @require_course_staff("STUDENT_INFO")
-    def render_student_info(self, data, suffix=''): # pylint: disable=W0613
+    def render_student_info(self, data, suffix=''):  # pylint: disable=W0613
         """
         Renders all relative information for a specific student's workflow.
 
@@ -204,9 +207,13 @@ class StaffInfoMixin(object):
         Must be course staff to render this view.
 
         """
-        student_id = data.params.get('student_id', '')
-        path, context = self.get_student_info_path_and_context(student_id)
-        return self.render_assessment(path, context)
+        try:
+            student_id = data.params.get('student_id', '')
+            path, context = self.get_student_info_path_and_context(student_id)
+            return self.render_assessment(path, context)
+
+        except PeerAssessmentInternalError as ex:
+            return self.render_error(self._(ex.message))
 
     def get_student_info_path_and_context(self, student_id):
         """
@@ -262,8 +269,13 @@ class StaffInfoMixin(object):
         if "example-based-assessment" in assessment_steps:
             example_based_assessment = ai_api.get_latest_assessment(submission_uuid)
 
+        submission_cancellation = peer_api.get_submission_cancellation(submission_uuid)
+        if submission_cancellation:
+            submission_cancellation['cancelled_by'] = self.get_username(submission_cancellation['cancelled_by_id'])
+
         context = {
             'submission': submission,
+            'submission_cancellation': submission_cancellation,
             'peer_assessments': peer_assessments,
             'submitted_assessments': submitted_assessments,
             'self_assessment': self_assessment,
@@ -317,3 +329,45 @@ class StaffInfoMixin(object):
                 'success': False,
                 'msg': self._(u"An error occurred while rescheduling tasks: {}".format(ex))
             }
+
+    @XBlock.json_handler
+    @require_course_staff("STUDENT_INFO")
+    def cancel_submission(self, data, suffix=''):
+        """
+            This will cancel the peer workflow for the particular submission.
+
+            Args:
+                data (dict): Data contain two attributes: submission_uuid and
+                    comments. submission_uuid is id of submission which is to be
+                    removed from the grading pool.comments is the reason given
+                    by the user.
+
+                suffix (not used)
+
+            Return:
+                Json serializable dict with the following elements:
+                    'success': (bool) Indicates whether or not the workflow cancelled successfully.
+                    'msg': The response (could be error message or success message).
+        """
+        submission_uuid = data.get('submission_uuid')
+        comments = data.get('comments')
+
+        if not comments:
+            return {"success": False, "msg": self._(u'Please enter valid reason to remove the submission.')}
+
+        student_item_dict = self.get_student_item_dict()
+        try:
+            peer_api.cancel_submission_peer_workflow(
+                submission_uuid=submission_uuid, comments=comments, cancelled_by_id=student_item_dict['student_id']
+            )
+            return {"success": True, 'msg': self._(u"Student submission was removed from the peer grading pool."
+                                                       u" If you'd like to allow the student to submit a new response,"
+                                                       u" please also reset the student state of the problem from"
+                                                       u" the Instructor Dashboard.")}
+        except (
+                PeerAssessmentWorkflowError,
+                PeerAssessmentInternalError
+        ) as ex:
+            msg = ex.message
+            logger.exception(msg)
+            return {"success": False, 'msg': msg}

openassessment/xblock/static/js/fixtures/templates.json

@@ -656,6 +656,19 @@
         "output": "oa_staff_info.html"
     },
     {
+        "template": "openassessmentblock/staff_debug/student_info.html",
+        "context": {
+            "submission": {
+                "image_url": "/test-url",
+                "answer":{
+                    "text": "testing response text"
+                }
+            },
+            "submission_cancellation": 0
+        },
+        "output": "oa_student_info.html"
+    },
+    {
         "template": "openassessmentblock/peer/oa_peer_assessment.html",
         "context": {
             "rubric_criteria": [

openassessment/xblock/static/js/spec/lms/oa_staff_info.js

@@ -34,6 +34,14 @@ describe("OpenAssessment.StaffInfoView", function() {
             }).promise();
         };
 
+        var successPromise = $.Deferred(
+            function(defer) { defer.resolve(); }
+        ).promise();
+
+        this.cancelSubmission = function(submissionUUID) {
+            return successPromise;
+        };
+
         this.data = {};
 
     };
@@ -153,4 +161,49 @@ describe("OpenAssessment.StaffInfoView", function() {
         expect(server.rescheduleUnfinishedTasks).toHaveBeenCalled();
     });
 
+    it("updates submission cancellation button when comments changes", function() {
+        // Prevent the server's response from resolving,
+        // so we can see what happens before view gets re-rendered.
+        spyOn(server, 'cancelSubmission').andCallFake(function() {
+            return $.Deferred(function(defer) {}).promise();
+        });
+
+        // Load the fixture
+        loadFixtures('oa_student_info.html');
+
+        var el = $("#openassessment-base").get(0);
+        var view = new OpenAssessment.StaffInfoView(el, server, baseView);
+
+        // comments is blank --> cancel submission button disabled
+        view.comment('');
+        view.handleCommentChanged();
+        expect(view.cancelSubmissionEnabled()).toBe(false);
+
+        // Response is whitespace --> cancel submission button disabled
+        view.comment('               \n      \n      ');
+        view.handleCommentChanged();
+        expect(view.cancelSubmissionEnabled()).toBe(false);
+
+        // Response is not blank --> cancel submission button enabled
+        view.comment('Test comments');
+        view.handleCommentChanged();
+        expect(view.cancelSubmissionEnabled()).toBe(true);
+    });
+
+    it("submits the cancel submission comments to the server", function() {
+        spyOn(server, 'cancelSubmission').andCallThrough();
+
+        // Load the fixture
+        loadFixtures('oa_student_info.html');
+
+        var el = $("#openassessment-base").get(0);
+        var view = new OpenAssessment.StaffInfoView(el, server, baseView);
+
+        view.comment('Test comments');
+        view.cancelSubmission('Bob');
+
+        expect(server.cancelSubmission).toHaveBeenCalledWith('Bob', 'Test comments');
+    });
+
+
 });

openassessment/xblock/static/js/spec/oa_server.js

@@ -130,6 +130,26 @@ describe("OpenAssessment.Server", function() {
         });
     });
 
+    it("sends a submission to XBlock for cancellation", function() {
+        stubAjax(true, {success:true, msg:'test message'});
+
+        var submissionUUID = 'Bob';
+        var comments = 'Test comments';
+        var success = false;
+        server.cancelSubmission(submissionUUID, comments).done(
+            function() {
+                success=true;
+            }
+        );
+
+        expect(success).toBe(true);
+        expect($.ajax).toHaveBeenCalledWith({
+            url: '/cancel_submission',
+            type: "POST",
+            data: JSON.stringify({submission_uuid: submissionUUID, comments: comments})
+        });
+    });
+
     it("saves a response submission", function() {
         stubAjax(true, {'success': true, 'msg': ''});
         var success = false;

openassessment/xblock/static/js/src/lms/oa_base.js

@@ -48,9 +48,8 @@ OpenAssessment.BaseView.prototype = {
     Args:
         parentSel (JQuery selector): CSS selector for the container element.
     **/
-    setUpCollapseExpand: function(parentSel) {
-        parentSel.find('.ui-toggle-visibility__control').click(
-            function(eventData) {
+    setUpCollapseExpand: function (parentSel) {
+        parentSel.on('click', '.ui-toggle-visibility__control', function (eventData) {
                 var sel = $(eventData.target).closest('.ui-toggle-visibility');
                 sel.toggleClass('is--collapsed');
             }

openassessment/xblock/static/js/src/lms/oa_staff_info.js

@@ -53,10 +53,23 @@ OpenAssessment.StaffInfoView.prototype = {
             function(html) {
                 // Load the HTML and install event handlers
                 $('#openassessment__student-info', view.element).replaceWith(html);
+
+                // Install key handler for new staff grade Save button.
+                var selCancelSub = $('#openassessment__staff-info__cancel__submission', this.element);
+                selCancelSub.on('click', '#submit_cancel_submission', function (eventObject) {
+                        eventObject.preventDefault();
+                        view.cancelSubmission($(this).data('submission-uuid'));
+                    }
+                );
+
+                // Install change handler for textarea (to enable cancel submission button)
+                var handleChange = function(eventData) { view.handleCommentChanged(); };
+                selCancelSub.find('#staff-info__cancel-submission__comments').on('change keyup drop paste', handleChange);
+
             }
         ).fail(function(errMsg) {
                 view.showLoadError('student_info');
-            });
+        });
     },
 
     /**
@@ -64,6 +77,7 @@ OpenAssessment.StaffInfoView.prototype = {
      **/
     installHandlers: function() {
         var sel = $('#openassessment__staff-info', this.element);
+        var selStudentInfo = $('#openassessment__student-info', this.element);
         var view = this;
 
         if (sel.length <= 0) {
@@ -71,6 +85,7 @@ OpenAssessment.StaffInfoView.prototype = {
         }
 
         this.baseView.setUpCollapseExpand(sel, function() {});
+        this.baseView.setUpCollapseExpand(selStudentInfo, function() {});
 
         // Install key handler for student id field
         sel.find('#openassessment_student_info_form').submit(
@@ -111,7 +126,6 @@ OpenAssessment.StaffInfoView.prototype = {
 
      **/
     scheduleTraining: function() {
-        var view = this;
         this.server.scheduleTraining().done(
                 function(msg) {
                     $('#schedule_training_message', this.element).text(msg)
@@ -136,5 +150,78 @@ OpenAssessment.StaffInfoView.prototype = {
             ).fail(function(errMsg) {
                 $('#reschedule_unfinished_tasks_message', this.element).text(errMsg)
             });
+    },
+
+    /**
+     Upon request, cancel the submission from grading pool.
+     **/
+    cancelSubmission: function(submissionUUID) {
+        // Immediately disable the submit button to prevent multiple submission
+        this.cancelSubmissionEnabled(false);
+        var view = this;
+        var sel = $('#openassessment__student-info', this.element);
+        var comments = sel.find('#staff-info__cancel-submission__comments').val();
+        this.server.cancelSubmission(submissionUUID, comments).done(
+            function(msg) {
+                $('.cancel-submission-error').html('');
+                $('#openassessment__staff-info__cancel__submission', view.element).html(msg);
+            }
+        ).fail(function(errMsg) {
+                $('.cancel-submission-error').html(errMsg);
+        });
+    },
+
+    /**
+    Enable/disable the cancel submission button.
+    Check whether the cancel submission button is enabled.
+
+    Args:
+        enabled (bool): If specified, set the state of the button.
+
+    Returns:
+        bool: Whether the button is enabled.
+
+    Examples:
+        >> view.submitEnabled(true);  // enable the button
+        >> view.submitEnabled();  // check whether the button is enabled
+        >> true
+    **/
+    cancelSubmissionEnabled: function(enabled) {
+        var sel = $('#submit_cancel_submission', this.element);
+        if (typeof enabled === 'undefined') {
+            return !sel.hasClass('is--disabled');
+        } else {
+            sel.toggleClass('is--disabled', !enabled);
+        }
+    },
+
+    /**
+    Set the comment text.
+    Retrieve the comment text.
+
+    Args:
+        text (string): reason to .
+
+    Returns:
+        string: The current comment text.
+    **/
+    comment: function(text) {
+        var sel = $('#staff-info__cancel-submission__comments', this.element);
+        if (typeof text === 'undefined') {
+            return sel.val();
+        } else {
+            sel.val(text);
+        }
+    },
+
+    /**
+    Enable/disable the cancel submission based on whether
+    the user has entered a comment.
+    **/
+    handleCommentChanged: function() {
+        // Enable the cancel submission button only for non-blank comments
+        var isBlank = ($.trim(this.comment()) !== '');
+        this.cancelSubmissionEnabled(isBlank);
     }
+
 };

openassessment/xblock/static/js/src/oa_server.js

@@ -549,6 +549,34 @@ if (typeof OpenAssessment.Server == "undefined" || !OpenAssessment.Server) {
                         defer.rejectWith(this, [gettext('Could not retrieve download url.')]);
                     });
             }).promise();
+        },
+
+        /**
+            Cancel the submission from peer grading pool.
+            Args:
+                submissionUUID: ID for submission to be cancelled from pool.
+                comments: reason to cancel the submission
+          **/
+        cancelSubmission: function (submissionUUID, comments) {
+            var url = this.url('cancel_submission');
+            var payload = JSON.stringify({
+                submission_uuid: submissionUUID,
+                comments: comments
+            });
+            return $.Deferred(function (defer) {
+                $.ajax({ type: "POST", url: url, data: payload }).done(
+                    function(data) {
+                        if (data.success) {
+                            defer.resolveWith(this, [data.msg]);
+                        }
+                        else {
+                            defer.rejectWith(this, [data.msg]);
+                        }
+                    }
+                ).fail(function(data) {
+                    defer.rejectWith(this, [gettext('The submission could not be removed from grading pool.')]);
+                });
+            }).promise();
         }
     };
 }

openassessment/xblock/static/sass/oa/elements/_staff.scss

@@ -133,4 +133,19 @@
     }
   }
 
+  // UI cancel submission.
+  .staff-info__cancel-submission__content {
+    textarea {
+      width: 100%;
+      height: 100px;
+      text-align: left;
+    }
+
+    ul.list--actions {
+      .action--submit {
+        margin: 10px 0px;
+      }
+    }
+  }
+
 }

openassessment/xblock/test/test_staff_info.py

@@ -224,6 +224,31 @@ class TestCourseStaff(XBlockHandlerTestCase):
         self.assertEquals([], context['peer_assessments'])
         self.assertEquals("openassessmentblock/staff_debug/student_info.html", path)
 
+    @scenario('data/basic_scenario.xml', user_id='Bob')
+    def test_staff_debug_student_info_with_cancelled_submission(self, xblock):
+        # Simulate that we are course staff
+        xblock.xmodule_runtime = self._create_mock_runtime(
+            xblock.scope_ids.usage_id, True, False, "Bob"
+        )
+
+        bob_item = STUDENT_ITEM.copy()
+        bob_item["item_id"] = xblock.scope_ids.usage_id
+        # Create a submission for Bob, and corresponding workflow.
+        submission = sub_api.create_submission(bob_item, {'text': "Bob Answer"})
+        peer_api.on_start(submission["uuid"])
+        workflow_api.create_workflow(submission["uuid"], ['self'])
+
+        peer_api.cancel_submission_peer_workflow(
+            submission_uuid=submission["uuid"],
+            comments="vulgar language",
+            cancelled_by_id=bob_item['student_id']
+        )
+
+        path, context = xblock.get_student_info_path_and_context("Bob")
+        self.assertEquals("Bob Answer", context['submission']['answer']['text'])
+        self.assertIsNotNone(context['submission_cancellation'])
+        self.assertEquals("openassessmentblock/staff_debug/student_info.html", path)
+
     @scenario('data/self_only_scenario.xml', user_id='Bob')
     def test_staff_debug_student_info_image_submission(self, xblock):
         # Simulate that we are course staff
@@ -491,6 +516,50 @@ class TestCourseStaff(XBlockHandlerTestCase):
         __, context = xblock.get_staff_path_and_context()
         self.assertNotIn('classifierset', context)
 
+    @scenario('data/basic_scenario.xml', user_id='Bob')
+    def test_cancel_submission_without_reason(self, xblock):
+        # If we're not course staff, we shouldn't be able to see the
+        # cancel submission option
+        xblock.xmodule_runtime = self._create_mock_runtime(
+            xblock.scope_ids.usage_id, False, False, "Bob"
+        )
+        resp = self.request(xblock, 'cancel_submission', json.dumps({}))
+        self.assertIn("you do not have permission", resp.decode('utf-8').lower())
+
+        # If we ARE course staff, then we should see the cancel submission option
+        # with valid error message.
+        xblock.xmodule_runtime.user_is_staff = True
+        resp = self.request(xblock, 'cancel_submission', json.dumps({}), response_format='json')
+        self.assertIn("Please enter valid reason", resp['msg'])
+        self.assertEqual(False, resp['success'])
+
+    @scenario('data/basic_scenario.xml', user_id='Bob')
+    def test_cancel_submission_full_flow(self, xblock):
+        # Simulate that we are course staff
+        xblock.xmodule_runtime = self._create_mock_runtime(
+            xblock.scope_ids.usage_id, True, False, "Bob"
+        )
+
+        bob_item = STUDENT_ITEM.copy()
+        bob_item["item_id"] = xblock.scope_ids.usage_id
+        # Create a submission for Bob, and corresponding workflow.
+        submission = sub_api.create_submission(bob_item, {'text': "Bob Answer"})
+        peer_api.on_start(submission["uuid"])
+        workflow_api.create_workflow(submission["uuid"], ['peer'])
+
+        incorrect_submission_uuid = 'abc'
+        params = {"submission_uuid": incorrect_submission_uuid, "comments": "vulgar language."}
+        # Raise flow not found exception.
+        resp = self.request(xblock, 'cancel_submission', json.dumps(params), response_format='json')
+        self.assertIn("Error finding workflow", resp['msg'])
+        self.assertEqual(False, resp['success'])
+
+        # Verify that we can render without error
+        params = {"submission_uuid": submission["uuid"], "comments": "vulgar language."}
+        resp = self.request(xblock, 'cancel_submission', json.dumps(params), response_format='json')
+        self.assertIn("Student submission was removed from the ", resp['msg'])
+        self.assertEqual(True, resp['success'])
+
     def _create_mock_runtime(self, item_id, is_staff, is_admin, anonymous_user_id):
         mock_runtime = Mock(
             course_id='test_course',