From cf326c24c9ce3fa119d29cf47fcf7ba92c3beb52 Mon Sep 17 00:00:00 2001
From: John Chilton <jmchilton@gmail.com>
Date: Sun, 21 Sep 2014 21:48:58 -0400
Subject: [PATCH] Reduce code duplication between job metrics and dependency
 resolution plugins. Same code reused again downstream in workflow schedulers
 plugin framework.

---
 lib/galaxy/jobs/metrics/__init__.py | 22 +++-----------------
 lib/galaxy/tools/deps/__init__.py   | 23 ++++-----------------
 lib/galaxy/util/plugin_config.py    | 32 +++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 38 deletions(-)
 create mode 100644 lib/galaxy/util/plugin_config.py

diff --git a/lib/galaxy/jobs/metrics/__init__.py b/lib/galaxy/jobs/metrics/__init__.py
index 19001622adb..d1b5db1db2b 100644
--- a/lib/galaxy/jobs/metrics/__init__.py
+++ b/lib/galaxy/jobs/metrics/__init__.py
@@ -3,7 +3,7 @@ import os
 
 from xml.etree import ElementTree
 
-from galaxy.util.submodules import submodules
+from galaxy.util import plugin_config
 from galaxy import util
 
 from ..metrics import formatting
@@ -49,17 +49,8 @@ class JobMetrics( object ):
         return self.job_instrumenters[ destination_id ].collect_properties( job_id, job_directory )
 
     def __plugins_dict( self ):
-        plugin_dict = {}
-        for plugin_module in self.__plugin_modules():
-            for clazz in plugin_module.__all__:
-                plugin_type = getattr( clazz, 'plugin_type', None )
-                if plugin_type:
-                    plugin_dict[ plugin_type ] = clazz
-        return plugin_dict
-
-    def __plugin_modules( self ):
         import galaxy.jobs.metrics.instrumenters
-        return submodules( galaxy.jobs.metrics.instrumenters )
+        return plugin_config.plugins_dict( galaxy.jobs.metrics.instrumenters, 'plugin_type' )
 
 
 class NullJobInstrumenter( object ):
@@ -117,14 +108,7 @@ class JobInstrumenter( object ):
         return per_plugin_properites
 
     def __plugins_for_element( self, plugins_element ):
-        plugins = []
-        for plugin_element in plugins_element.getchildren():
-            plugin_type = plugin_element.tag
-            plugin_kwds = dict( plugin_element.items() )
-            plugin_kwds.update( self.extra_kwargs )
-            plugin = self.plugin_classes[ plugin_type ]( **plugin_kwds )
-            plugins.append( plugin )
-        return plugins
+        return plugin_config.load_plugins_from_element(self.plugin_classes, plugins_element, self.extra_kwargs)
 
     @staticmethod
     def from_file( plugin_classes, conf_file, **kwargs ):
diff --git a/lib/galaxy/tools/deps/__init__.py b/lib/galaxy/tools/deps/__init__.py
index 0b72cb0ebeb..dd0b46961ed 100644
--- a/lib/galaxy/tools/deps/__init__.py
+++ b/lib/galaxy/tools/deps/__init__.py
@@ -12,7 +12,7 @@ from xml.etree import ElementTree
 from .resolvers import INDETERMINATE_DEPENDENCY
 from .resolvers.galaxy_packages import GalaxyPackageDependencyResolver
 from .resolvers.tool_shed_packages import ToolShedPackageDependencyResolver
-from galaxy.util.submodules import submodules
+from galaxy.util import plugin_config
 
 
 def build_dependency_manager( config ):
@@ -110,24 +110,9 @@ class DependencyManager( object ):
         :param root: Object representing the root ``<dependency_resolvers>`` object in the file.
         :type root: ``xml.etree.ElementTree.Element``
         """
-        resolvers = []
-        resolvers_element = root
-        for resolver_element in resolvers_element.getchildren():
-            resolver_type = resolver_element.tag
-            resolver_kwds = dict(resolver_element.items())
-            resolver = self.resolver_classes[resolver_type](self, **resolver_kwds)
-            resolvers.append(resolver)
-        return resolvers
+        extra_kwds = dict( dependency_manager=self )
+        return plugin_config.load_plugins_from_element( self.resolver_classes, root, extra_kwds )
 
     def __resolvers_dict( self ):
-        resolver_dict = {}
-        for resolver_module in self.__resolver_modules():
-            for clazz in resolver_module.__all__:
-                resolver_type = getattr(clazz, 'resolver_type', None)
-                if resolver_type:
-                    resolver_dict[resolver_type] = clazz
-        return resolver_dict
-
-    def __resolver_modules( self ):
         import galaxy.tools.deps.resolvers
-        return submodules( galaxy.tools.deps.resolvers )
+        return plugin_config.plugins_dict( galaxy.tools.deps.resolvers, 'resolver_type' )
diff --git a/lib/galaxy/util/plugin_config.py b/lib/galaxy/util/plugin_config.py
new file mode 100644
index 00000000000..823a1054658
--- /dev/null
+++ b/lib/galaxy/util/plugin_config.py
@@ -0,0 +1,32 @@
+from galaxy.util.submodules import submodules
+
+
+def plugins_dict(module, plugin_type_identifier):
+    """ Walk through all classes in submodules of module and find ones labelled
+    with specified plugin_type_identifier and throw in a dictionary to allow
+    constructions from plugins by these types later on.
+    """
+    plugin_dict = {}
+
+    for plugin_module in submodules( module ):
+        # FIXME: this is not how one is suppose to use __all__ why did you do
+        # this past John?
+        for clazz in plugin_module.__all__:
+            plugin_type = getattr( clazz, plugin_type_identifier, None )
+            if plugin_type:
+                plugin_dict[ plugin_type ] = clazz
+
+    return plugin_dict
+
+
+def load_plugins_from_element(plugins_dict, plugins_element, extra_kwds={}):
+    plugins = []
+
+    for plugin_element in plugins_element.getchildren():
+        plugin_type = plugin_element.tag
+        plugin_kwds = dict( plugin_element.items() )
+        plugin_kwds.update( extra_kwds )
+        plugin = plugins_dict[ plugin_type ]( **plugin_kwds )
+        plugins.append( plugin )
+
+    return plugins