X-Git-Url: http://git.tremily.us/?a=blobdiff_plain;ds=sidebyside;f=hooke%2Futil%2Fpluggable.py;h=1379c82c4ed5f6d05d950743d127a08656d3bd99;hb=b90995fb4b6d8151df862d40edc8c369d7052cfa;hp=0a491cb67b9491f4719292c86697422a6fd749a6;hpb=c46aaa51003a6722a28eea0e49f63ef1bb0e882d;p=hooke.git

diff --git a/hooke/util/pluggable.py b/hooke/util/pluggable.py
index 0a491cb..1379c82 100644
--- a/hooke/util/pluggable.py
+++ b/hooke/util/pluggable.py
@@ -2,24 +2,27 @@
 #
 # This file is part of Hooke.
 #
-# Hooke 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 3 of the License, or (at your option) any later version.
+# Hooke 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 3 of the
+# License, or (at your option) any later version.
 #
-# Hooke 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.
+# Hooke 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 Hooke.  If not, see
 # <http://www.gnu.org/licenses/>.
 
-"""`pluggable`
+"""``pluggable`` provides utility functions for extensible plugin modules.
 """
 
-from ..util.graph import Node, Graph
+import logging
+
+from ..compat.odict import odict
+from .graph import Node, Graph
 
 
 class IsSubclass (object):
@@ -58,6 +61,48 @@ class IsSubclass (object):
             return False
         return subclass
 
+
+def submods(this_modname, submodnames):
+    """Iterate through (submodname, submod) pairs.
+    """
+    for submodname in submodnames:
+        count = len([s for s in submodnames if s == submodname])
+        assert count > 0, 'No %s entries: %s' % (submodname, submodnames)
+        assert count == 1, 'Multiple (%d) %s entries: %s' \
+            % (count, submodname, submodnames)
+        try:
+            this_mod = __import__(this_modname, fromlist=[submodname])
+        except ImportError, e:
+            # Use the root logger because the 'hooke' logger is
+            # configured by a Hooke instance after module imports.
+            logging.warn('could not import %s from %s: %s'
+                         % (submodname, this_modname, e))
+            continue
+        submod = getattr(this_mod, submodname)
+        yield (submodname, submod)
+
+
+def construct_odict(this_modname, submodnames, class_selector,
+                    instantiate=True):
+    """Search the submodules `submodnames` of a module `this_modname`
+    for class objects for which `class_selector(class)` returns
+    `True`.  If `instantiate == True` these classes are instantiated
+    and stored in the returned :class:`hooke.compat.odict.odict` in
+    the order in which they were discovered.  Otherwise, the class
+    itself is stored.
+    """
+    objs = odict()
+    for submodname,submod in submods(this_modname, submodnames):
+        for objname in dir(submod):
+            obj = getattr(submod, objname)
+            if class_selector(obj):
+                if instantiate == True:
+                    obj = obj()
+                name = getattr(obj, 'name', submodname)
+                objs[name] = obj
+    return objs
+
+
 def construct_graph(this_modname, submodnames, class_selector,
                     assert_name_match=True):
     """Search the submodules `submodnames` of a module `this_modname`
@@ -72,13 +117,7 @@ def construct_graph(this_modname, submodnames, class_selector,
     is returned.
     """
     instances = {}
-    for submodname in submodnames:
-        count = len([s for s in submodnames if s == submodname])
-        assert count > 0, 'No %s entries: %s' % (submodname, submodnames)
-        assert count == 1, 'Multiple (%d) %s entries: %s' \
-            % (count, submodname, submodnames)
-        this_mod = __import__(this_modname, fromlist=[submodname])
-        submod = getattr(this_mod, submodname)
+    for submodname,submod in submods(this_modname, submodnames):
         for objname in dir(submod):
             obj = getattr(submod, objname)
             if class_selector(obj):