Backport PLIP 1406 for plone.app.registry 1.2.x

CHANGES.rst

@@ -4,7 +4,16 @@ Changelog
 1.2.5 (unreleased)
 ------------------
 
-- Nothing changed yet.
+New features:
+
+- Add support for *have* and *have-not* import conditions in
+  registry.xml
+  [datakurre]
+
+- Add support for optional condition attribute in registry.xml entries
+  to allow conditional importing of records. Conditions themselves are
+  not import (nor exported).
+  [datakurre]
 
 
 1.2.4 (2015-05-04)

README.rst

@@ -159,6 +159,38 @@ pairs. They can be configured like so::
         </value>
     </record>
 
+
+Conditional records
+~~~~~~~~~~~~~~~~~~~
+
+Importable records in ``registry.xml`` can be marked conditional with
+``condition`` attribute, which supports the following condition values:
+
+* ``installed my.package``, which causes record to be imported only when
+  python module ``my.package`` is available to be imported.
+
+* ``not-installed my.package``, which causes record to be imported only when
+  python module ``my.package`` is *not* available to be imported:
+
+* ``have my-feature``, which causes record to be imported only when
+  ZCML feature flag ``my-feature`` has been registered (Zope2 only)
+
+* ``not-have my-feature``, which causes record to be imported only when
+  ZCML feature flag ``my-feature`` has *not* been registered (Zope2 only)
+
+For example, the following ``registry.xml`` step at the GenericSetup profile of
+your policy product, would only import records when module ``my.package`` is
+available::
+
+    <registry>
+      <records interface="my.package.interfaces.IZooSettings"
+               condition="installed my.package">
+        <value key="entryPrice">40</value>
+        <value key="messageOfTheDay">We've got lions and tigers!</value>
+      </records>
+    </registry>
+
+
 Field references
 ~~~~~~~~~~~~~~~~
 

plone/app/registry/exportimport/handler.py

@@ -20,9 +20,33 @@
 
 from plone.supermodel.utils import prettyXML, elementToValue, valueToElement, ns
 
+from zope.configuration import config
+from zope.configuration import xmlconfig
+
 _marker = object()
 
 
+def evaluateCondition(expression):
+    """Evaluate import condition.
+
+    ``expression`` is a string of the form "verb arguments".
+
+    Currently the supported verbs are 'have', 'not-have',
+    'installed' and 'not-installed'.
+
+    The 'have' verb takes one argument: the name of a feature.
+    """
+    try:
+        import Zope2.App.zcml
+        context = Zope2.App.zcml._context or config.ConfigurationMachine()
+    except ImportError:
+        context = config.ConfigurationMachine()
+
+    handler = xmlconfig.ConfigurationHandler(context)
+    return handler.evaluateCondition(expression)
+
+
+
 def shouldPurgeList(value_node, key):
     for child in value_node:
         attrib = child.attrib
@@ -88,6 +112,9 @@ def importDocument(self, document):
         for node in tree:
             if not isinstance(node.tag, str):
                 continue
+            condition = node.attrib.get('condition', None)
+            if condition and not evaluateCondition(condition):
+                continue
             if node.tag.lower() == 'record':
                 self.importRecord(node)
             elif node.tag.lower() == 'records':

plone/app/registry/tests/test_exportimport.py

@@ -27,7 +27,9 @@
 from plone.app.registry.tests import data
 
 configuration = """\
-<configure xmlns="http://namespaces.zope.org/zope">
+<configure xmlns="http://namespaces.zope.org/zope"
+           xmlns:meta="http://namespaces.zope.org/meta">
+    <meta:provides feature="plone" />
     <include package="zope.component" file="meta.zcml" />
     <include package="plone.registry" />
     <include package="plone.app.registry.exportimport" file="handlers.zcml" />
@@ -43,7 +45,20 @@ def setUp(self):
         self.site = ObjectManager('plone')
         self.registry = Registry('portal_registry')
         provideUtility(provides=IRegistry, component=self.registry)
-        xmlconfig.xmlconfig(StringIO(configuration))
+        context = xmlconfig.string(configuration, execute=True)
+        try:
+            import Zope2.App.zcml
+            self._context = Zope2.App.zcml._context
+            Zope2.App.zcml._context = context
+        except ImportError:
+            pass
+
+    def tearDown(self):
+        try:
+            import Zope2.App.zcml
+            Zope2.App.zcml._context = self._context
+        except ImportError:
+            pass
 
     def assertXmlEquals(self, expected, actual):
 
@@ -293,6 +308,29 @@ def test_import_records_with_values(self):
         self.assertEqual(self.registry['plone.app.registry.tests.data.SomethingElse.name'], 'Magic')
         self.assertEqual(self.registry['plone.app.registry.tests.data.SomethingElse.age'], 42)
 
+    def test_import_records_nonexistant_interface(self):
+        xml = """\
+<registry>
+    <records interface="non.existant.ISchema" />
+</registry>
+"""
+        context = DummyImportContext(self.site, purge=False)
+        context._files = {'registry.xml': xml}
+
+        self.assertRaises(ImportError, importRegistry, context)
+
+    def test_import_records_nonexistant_interface_condition_not_installed(self):  # noqa
+        xml = """\
+<registry>
+    <records interface="non.existant.ISchema"
+             condition="not-installed non" />
+</registry>
+"""
+        context = DummyImportContext(self.site, purge=False)
+        context._files = {'registry.xml': xml}
+
+        self.assertRaises(ImportError, importRegistry, context)
+
     def test_import_value_only(self):
         xml = """\
 <registry>
@@ -310,8 +348,95 @@ def test_import_value_only(self):
         importRegistry(context)
 
         self.assertEquals(1, len(self.registry.records))
-        self.assertEquals(u"Simple record", self.registry.records['test.export.simple'].field.title)
-        self.assertEquals(u"Imported value", self.registry['test.export.simple'])
+        self.assertEquals(
+            u"Simple record",
+            self.registry.records['test.export.simple'].field.title
+        )
+        self.assertEquals(
+            u"Imported value",
+            self.registry['test.export.simple']
+        )
+
+    def test_import_value_only_condition_installed(self):
+        xml = """\
+<registry>
+    <record name="test.export.simple"
+            condition="installed non">
+        <value>Imported value</value>
+    </record>
+</registry>
+"""
+        context = DummyImportContext(self.site, purge=False)
+        context._files = {'registry.xml': xml}
+
+        self.registry.records['test.export.simple'] = \
+            Record(field.TextLine(title=u"Simple record", default=u"N/A"),
+                   value=u"Sample value")
+        importRegistry(context)
+
+        self.assertEquals(1, len(self.registry.records))
+        self.assertEquals(
+            u"Simple record",
+            self.registry.records['test.export.simple'].field.title
+        )
+        self.assertEquals(
+            u"Sample value",
+            self.registry['test.export.simple']
+        )
+
+    def test_import_value_only_condition_have(self):
+        xml = """\
+<registry>
+    <record name="test.export.simple"
+            condition="have plone">
+        <value>Imported value</value>
+    </record>
+</registry>
+"""
+        context = DummyImportContext(self.site, purge=False)
+        context._files = {'registry.xml': xml}
+
+        self.registry.records['test.export.simple'] = \
+            Record(field.TextLine(title=u"Simple record", default=u"N/A"),
+                   value=u"Sample value")
+        importRegistry(context)
+
+        self.assertEquals(1, len(self.registry.records))
+        self.assertEquals(
+            u"Simple record",
+            self.registry.records['test.export.simple'].field.title
+        )
+        self.assertEquals(
+            u"Imported value",
+            self.registry['test.export.simple']
+        )
+
+    def test_import_value_only_condition_not_have(self):
+        xml = """\
+<registry>
+    <record name="test.export.simple"
+            condition="not-have plone">
+        <value>Imported value</value>
+    </record>
+</registry>
+"""
+        context = DummyImportContext(self.site, purge=False)
+        context._files = {'registry.xml': xml}
+
+        self.registry.records['test.export.simple'] = \
+            Record(field.TextLine(title=u"Simple record", default=u"N/A"),
+                   value=u"Sample value")
+        importRegistry(context)
+
+        self.assertEquals(1, len(self.registry.records))
+        self.assertEquals(
+            u"Simple record",
+            self.registry.records['test.export.simple'].field.title
+        )
+        self.assertEquals(
+            u"Sample value",
+            self.registry['test.export.simple']
+        )
 
     def test_import_interface_and_value(self):
         xml = """\