XBlockAsides Hello world example

cms/lib/xblock/tagging.py

@@ -0,0 +1,92 @@
+"""
+Example implementation of Structured Tagging based on XBlockAsides
+"""
+
+from xblock.core import XBlockAside
+from xblock.fragment import Fragment
+from xblock.fields import Scope, Dict
+from xmodule.x_module import STUDENT_VIEW
+from xmodule.capa_module import CapaModule
+from abc import ABCMeta, abstractproperty
+from edxmako.shortcuts import render_to_string
+
+
+_ = lambda text: text
+
+
+class AbstractTag(object):
+    """
+    Abstract class for tags
+    """
+    __metaclass__ = ABCMeta
+
+    @abstractproperty
+    def key(self):
+        """
+        Subclasses must implement key
+        """
+        raise NotImplementedError('Subclasses must implement key')
+
+    @abstractproperty
+    def name(self):
+        """
+        Subclasses must implement name
+        """
+        raise NotImplementedError('Subclasses must implement name')
+
+    @abstractproperty
+    def allowed_values(self):
+        """
+        Subclasses must implement allowed_values
+        """
+        raise NotImplementedError('Subclasses must implement allowed_values')
+
+
+class LearningOutcomeTag(AbstractTag):
+    """
+    Particular implementation tags for learning outcomes
+    """
+    @property
+    def key(self):
+        """ Identifier for the learning outcome selector """
+        return 'learning_outcome_tag'
+
+    @property
+    def name(self):
+        """ Label for the learning outcome selector """
+        return _('Learning outcomes')
+
+    @property
+    def allowed_values(self):
+        """ Allowed values for the learning outcome selector """
+        return {'test1': 'Test 1', 'test2': 'Test 2', 'test3': 'Test 3'}
+
+
+class StructuredTagsAside(XBlockAside):
+    """
+    Aside that allows tagging blocks
+    """
+    saved_tags = Dict(help=_("Dictionary with the available tags"),
+                      scope=Scope.content,
+                      default={},)
+    available_tags = [LearningOutcomeTag()]
+
+    @XBlockAside.aside_for(STUDENT_VIEW)
+    def student_view_aside(self, block, context):
+        """
+        Display the tag selector with specific categories and allowed values,
+        depending on the context.
+        """
+        if isinstance(block, CapaModule):
+            tags = []
+            for tag in self.available_tags:
+                tags.append({
+                    'key': tag.key,
+                    'title': tag.name,
+                    'values': tag.allowed_values,
+                    'current_value': self.saved_tags.get(tag.key, None),
+                })
+            return Fragment(render_to_string('structured_tags_block.html', {'tags': tags}))
+            #return Fragment(u'<div class="xblock-render">Hello world!!!</div>')
+        else:
+            return Fragment(u'')