1 files changed, 63 insertions, 0 deletions
diff --git a/src/buildstream/_elementfactory.py b/src/buildstream/_elementfactory.py
new file mode 100644
index 000000000..d6591bf4c
--- /dev/null
+++ b/src/buildstream/_elementfactory.py
@@ -0,0 +1,63 @@
+#
+#  Copyright (C) 2016 Codethink Limited
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
+
+from . import _site
+from ._plugincontext import PluginContext
+from .element import Element
+
+
+# A ElementFactory creates Element instances
+# in the context of a given factory
+#
+# Args:
+#     plugin_base (PluginBase): The main PluginBase object to work with
+#     plugin_origins (list):    Data used to search for external Element plugins
+#
+class ElementFactory(PluginContext):
+
+    def __init__(self, plugin_base, *,
+                 format_versions={},
+                 plugin_origins=None):
+
+        super().__init__(plugin_base, Element, [_site.element_plugins],
+                         plugin_origins=plugin_origins,
+                         format_versions=format_versions)
+
+    # create():
+    #
+    # Create an Element object, the pipeline uses this to create Element
+    # objects on demand for a given pipeline.
+    #
+    # Args:
+    #    context (object): The Context object for processing
+    #    project (object): The project object
+    #    meta (object): The loaded MetaElement
+    #
+    # Returns: A newly created Element object of the appropriate kind
+    #
+    # Raises:
+    #    PluginError (if the kind lookup failed)
+    #    LoadError (if the element itself took issue with the config)
+    #
+    def create(self, context, project, meta):
+        element_type, default_config = self.lookup(meta.kind)
+        element = element_type(context, project, meta, default_config)
+        version = self._format_versions.get(meta.kind, 0)
+        self._assert_plugin_format(element, version)
+        return element