Merge pull request #10253 from edx/renzo/studio-entity-plugins

Groundwork for Studio extensibility

cms/lib/studio_tabs.py

+"""Studio tab plugin manager and API."""
+import abc
+
+from openedx.core.lib.api.plugins import PluginManager
+
+
+class StudioTabPluginManager(PluginManager):
+    """Manager for all available Studio tabs.
+
+    Examples of Studio tabs include Courses, Libraries, and Programs. All Studio
+    tabs should implement `StudioTab`.
+    """
+    NAMESPACE = 'openedx.studio_tab'
+
+    @classmethod
+    def get_enabled_tabs(cls):
+        """Returns a list of enabled Studio tabs."""
+        tabs = cls.get_available_plugins()
+        enabled_tabs = [tab for tab in tabs.viewvalues() if tab.is_enabled()]
+
+        return enabled_tabs
+
+
+class StudioTab(object):
+    """Abstract class used to represent Studio tabs.
+
+    Examples of Studio tabs include Courses, Libraries, and Programs.
+    """
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractproperty
+    def tab_text(self):
+        """Text to display in a tab used to navigate to a list of instances of this tab.
+
+        Should be internationalized using `ugettext_noop()` since the user won't be available in this context.
+        """
+        pass
+
+    @abc.abstractproperty
+    def button_text(self):
+        """Text to display in a button used to create a new instance of this tab.
+
+        Should be internationalized using `ugettext_noop()` since the user won't be available in this context.
+        """
+        pass
+
+    @abc.abstractproperty
+    def view_name(self):
+        """Name of the view used to render this tab.
+
+        Used within templates in conjuction with Django's `reverse()` to generate a URL for this tab.
+        """
+        pass
+
+    @abc.abstractmethod
+    def is_enabled(cls, user=None):  # pylint: disable=no-self-argument,unused-argument
+        """Indicates whether this tab should be enabled.
+
+        This is a class method; override with @classmethod.
+
+        Keyword Arguments:
+            user (User): The user signed in to Studio.
+        """
+        pass

cms/lib/tests/test_studio_tabs.py

+"""Tests for the Studio tab plugin API."""
+from django.test import TestCase
+import mock
+
+from cms.lib.studio_tabs import StudioTabPluginManager
+from openedx.core.lib.api.plugins import PluginError
+
+
+class TestStudioTabPluginApi(TestCase):
+    """Unit tests for the Studio tab plugin API."""
+
+    @mock.patch('cms.lib.studio_tabs.StudioTabPluginManager.get_available_plugins')
+    def test_get_enabled_tabs(self, get_available_plugins):
+        """Verify that only enabled tabs are retrieved."""
+        enabled_tab = self._mock_tab(is_enabled=True)
+        mock_tabs = {
+            'disabled_tab': self._mock_tab(),
+            'enabled_tab': enabled_tab,
+        }
+
+        get_available_plugins.return_value = mock_tabs
+
+        self.assertEqual(StudioTabPluginManager.get_enabled_tabs(), [enabled_tab])
+
+    def test_get_invalid_plugin(self):
+        """Verify that get_plugin fails when an invalid plugin is requested."""
+        with self.assertRaises(PluginError):
+            StudioTabPluginManager.get_plugin('invalid_tab')
+
+    def _mock_tab(self, is_enabled=False):
+        """Generate a mock tab."""
+        tab = mock.Mock()
+        tab.is_enabled = mock.Mock(return_value=is_enabled)
+
+        return tab