Merge pull request #37 from pmitros/export_xml

parse xml

recommender/recommender.py

@@ -4,7 +4,9 @@ students solving a given problem.
 """
 import hashlib
 import json
+import lxml.etree as etree
 import pkg_resources
+import xml.dom.minidom as md
 
 from copy import deepcopy
 
@@ -968,6 +970,23 @@ class RecommenderXBlock(HelperXBlock):
         frag.initialize_js('RecommenderXBlock')
         return frag
 
+    def add_xml_to_node(self, node):
+        """
+        Serialize the XBlock to XML for exporting.
+        """
+        node.tag = 'recommender'
+
+        node.set('intro_enabled', str(self.intro_enabled))
+        node.set('DISABLE_DEV_UX', str(self.client_side_settings['DISABLE_DEV_UX']))
+        node.set('ENTRIES_PER_PAGE', str(self.client_side_settings['ENTRIES_PER_PAGE']))
+        node.set('PAGE_SPAN', str(self.client_side_settings['PAGE_SPAN']))
+
+        el = etree.SubElement(node, 'resources')
+        ## Note: The line below does not work in edX platform. 
+        ## We should figure out if the appropriate scope is available during import/export
+        ## TODO: Talk to Cale
+        el.text = unicode(json.dumps(self.recommendations))
+
     @staticmethod
     def workbench_scenarios():
         """
@@ -979,14 +998,19 @@ class RecommenderXBlock(HelperXBlock):
                 """
                 <vertical_demo>
                     <html_demo><img class="question" src="http://people.csail.mit.edu/swli/edx/recommendation/img/pset.png"></img></html_demo>
-                    <recommender>
-                        {"id": 1, "title": "Covalent bonding and periodic trends", "upvotes" : 15, "downvotes" : 5, "url" : "https://courses.edx.org/courses/MITx/3.091X/2013_Fall/courseware/SP13_Week_4/SP13_Periodic_Trends_and_Bonding/", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/videopage1.png", "descriptionText" : "short description for Covalent bonding and periodic trends"}
-                        {"id": 2, "title": "Polar covalent bonds and electronegativity", "upvotes" : 10, "downvotes" : 7, "url" : "https://courses.edx.org/courses/MITx/3.091X/2013_Fall/courseware/SP13_Week_4/SP13_Covalent_Bonding/", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/videopage2.png", "descriptionText" : "short description for Polar covalent bonds and electronegativity"}
-                        {"id": 3, "title": "Longest wavelength able to to break a C-C bond ...", "upvotes" : 1230, "downvotes" : 7, "url" : "https://answers.yahoo.com/question/index?qid=20081112142253AA1kQN1", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/dispage1.png", "descriptionText" : "short description for Longest wavelength able to to break a C-C bond ..."}
-                        {"id": 4, "title": "Calculate the maximum wavelength of light for ...", "upvotes" : 10, "downvotes" : 3457, "url" : "https://answers.yahoo.com/question/index?qid=20100110115715AA6toHw", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/dispage2.png", "descriptionText" : "short description for Calculate the maximum wavelength of light for ..."}
-                        {"id": 5, "title": "Covalent bond - wave mechanical concept", "upvotes" : 10, "downvotes" : 7, "url" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage1.png", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage1.png", "descriptionText" : "short description for Covalent bond - wave mechanical concept"}
-                        {"id": 6, "title": "Covalent bond - Energetics of covalent bond", "upvotes" : 10, "downvotes" : 7, "url" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage2.png", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage2.png", "descriptionText" : "short description for Covalent bond - Energetics of covalent bond"}
+                    <recommender intro_enabled="True" DISABLE_DEV_UX="True" ENTRIES_PER_PAGE="3" PAGE_SPAN="1">
+                        <resources>
+                            [
+                                {"id": 1, "title": "Covalent bonding and periodic trends", "upvotes" : 15, "downvotes" : 5, "url" : "https://courses.edx.org/courses/MITx/3.091X/2013_Fall/courseware/SP13_Week_4/SP13_Periodic_Trends_and_Bonding/", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/videopage1.png", "descriptionText" : "short description for Covalent bonding and periodic trends"},
+                                {"id": 2, "title": "Polar covalent bonds and electronegativity", "upvotes" : 10, "downvotes" : 7, "url" : "https://courses.edx.org/courses/MITx/3.091X/2013_Fall/courseware/SP13_Week_4/SP13_Covalent_Bonding/", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/videopage2.png", "descriptionText" : "short description for Polar covalent bonds and electronegativity"},
+                                {"id": 3, "title": "Longest wavelength able to to break a C-C bond ...", "upvotes" : 1230, "downvotes" : 7, "url" : "https://answers.yahoo.com/question/index?qid=20081112142253AA1kQN1", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/dispage1.png", "descriptionText" : "short description for Longest wavelength able to to break a C-C bond ..."},
+                                {"id": 4, "title": "Calculate the maximum wavelength of light for ...", "upvotes" : 10, "downvotes" : 3457, "url" : "https://answers.yahoo.com/question/index?qid=20100110115715AA6toHw", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/dispage2.png", "descriptionText" : "short description for Calculate the maximum wavelength of light for ..."},
+                                {"id": 5, "title": "Covalent bond - wave mechanical concept", "upvotes" : 10, "downvotes" : 7, "url" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage1.png", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage1.png", "descriptionText" : "short description for Covalent bond - wave mechanical concept"},
+                                {"id": 6, "title": "Covalent bond - Energetics of covalent bond", "upvotes" : 10, "downvotes" : 7, "url" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage2.png", "description" : "http://people.csail.mit.edu/swli/edx/recommendation/img/textbookpage2.png", "descriptionText" : "short description for Covalent bond - Energetics of covalent bond"}
+                            ]
+                        </resources>
                     </recommender>
+                    <recommender />
                 </vertical_demo>
                 """
             ),
@@ -999,11 +1023,35 @@ class RecommenderXBlock(HelperXBlock):
 
         """
         block = runtime.construct_xblock_from_class(cls, keys)
-        lines = []
-        for line in node.text.split('\n'):
-            line = line.strip()
-            if len(line) > 2:
-                lines.append(json.loads(line))
 
-        block.default_recommendations = data_structure_upgrade(lines)
+        node_xml = etree.tostring(node, encoding='utf-8')
+        try:
+            dom = md.parseString(node_xml.encode('utf-8'))
+        except Exception:
+            raise UpdateFromXmlError("An error occurred while parsing the XML content.")
+        root = dom.documentElement
+
+        if root.tagName != 'recommender':
+            raise UpdateFromXmlError("XML content must contain an 'recommender' root element.")
+
+        block.intro_enabled = (root.getAttribute('intro_enabled').lower().strip() != "false")
+        block.client_side_settings['DISABLE_DEV_UX'] = (root.getAttribute('DISABLE_DEV_UX').lower().strip() != "false")
+
+        for tag in ['ENTRIES_PER_PAGE', 'PAGE_SPAN']:
+            if root.getAttribute(tag) is not None and len(root.getAttribute(tag)) > 0:
+                block.client_side_settings[tag] = int(root.getAttribute(tag))
+
+        el = root.getElementsByTagName('resources')
+        if el is not None and len(el) == 1:
+            text = el[0].childNodes[0].nodeValue
+            if text != '' and text is not None:
+                lines = json.loads(text)
+                block.default_recommendations = data_structure_upgrade(lines)
+
         return block
+
+class UpdateFromXmlError(Exception):
+    """
+    Error occurred while deserializing the TaggedText XBlock content from XML.
+    """
+    pass
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