From 7c110d15b872cfdd3ac5cdd4342f1f60a833bc57 Mon Sep 17 00:00:00 2001
From: Doug Blank <doug.blank@gmail.com>
Date: Wed, 25 Aug 2010 13:30:59 +0000
Subject: [PATCH] Added plugin.depends_on = ['plugin_id', ...] for
 plugin.load_on_reg plugins

svn: r15816
---
 src/gen/plug/_manager.py   | 31 +++++++++++++++++++++++++++++++
 src/gen/plug/_pluginreg.py | 10 ++++++++++
 2 files changed, 41 insertions(+)

diff --git a/src/gen/plug/_manager.py b/src/gen/plug/_manager.py
index 949304888..85465d30a 100644
--- a/src/gen/plug/_manager.py
+++ b/src/gen/plug/_manager.py
@@ -129,9 +129,40 @@ class BasePluginManager(object):
         if load_on_reg:
             # Run plugins that request to be loaded on startup and
             # have a load_on_reg callable.
+            # first, remove hidden
+            plugins_to_load = []
             for plugin in self.__pgr.filter_load_on_reg():
                 if plugin.id in config.get("plugin.hiddenplugins"):
                     continue
+                plugins_to_load.append(plugin)
+            # next, sort on dependencies
+            # Probably a more effecient method to get dependency graph:
+            plugins_sorted = []
+            count = 0
+            max_count = len(plugins_to_load)
+            while plugins_to_load:
+                for plugin in plugins_to_load[:]: # copy of list
+                    delay = False
+                    for depend in plugin.depends_on:
+                        if depend not in [p.id for p in plugins_sorted]:
+                            delay = True
+                            break
+                    if delay:
+                        pass # wait till next loop
+                    else:
+                        if plugin not in plugins_sorted:
+                            plugins_sorted.append(plugin)
+                        if plugin in plugins_to_load:
+                            plugins_to_load.remove(plugin)
+                count += 1
+                if count > max_count:
+                    print "Cannot resolve the following plugin dependencies:"
+                    for plugin in plugins_to_load:
+                        print "   Plugin '%s' requires: %s" % (
+                            plugin.id, plugin.depends_on)
+                    break
+            # now load them:
+            for plugin in plugins_sorted:
                 mod = self.load_plugin(plugin)
                 if hasattr(mod, "load_on_reg"):
                     try:
diff --git a/src/gen/plug/_pluginreg.py b/src/gen/plug/_pluginreg.py
index 2d5e4daf6..f0def694e 100644
--- a/src/gen/plug/_pluginreg.py
+++ b/src/gen/plug/_pluginreg.py
@@ -351,6 +351,7 @@ class PluginData(object):
         self._load_on_reg = False
         self._icons = []
         self._icondir = None
+        self._depends_on = []
         #derived var
         self.mod_name = None
         #RELCALC attr
@@ -527,6 +528,14 @@ class PluginData(object):
     def _set_icondir(self, icondir):
         self._icondir = icondir
 
+    def _get_depends_on(self):
+        return self._depends_on
+
+    def _set_depends_on(self, depends):
+        if not isinstance(depends, list):
+            raise ValueError, 'Plugin must have depends_on as a list'
+        self._depends_on = depends
+
     id = property(_get_id, _set_id)
     name = property(_get_name, _set_name)
     name_accell = property(_get_name_accell, _set_name_accell)
@@ -544,6 +553,7 @@ class PluginData(object):
     load_on_reg = property(_get_load_on_reg, _set_load_on_reg)
     icons = property(_get_icons, _set_icons)
     icondir = property(_get_icondir, _set_icondir)
+    depends_on = property(_get_depends_on, _set_depends_on)
     
     def statustext(self):
         return STATUSTEXT[self.status]