[ADD] module install/uninstall hooks.

Since 4ec71c74d1, migration scripts
are not executed at module install anymore.
As this behavior was missused as "init" scripts (see [1]), this
commit re-add this possiblity via hooks.

There are 3 hooks that can be declared in the manifest file:
 - pre_init_hook: called before module installation
 - post_init_hook: called after module installation
 - uninstall_hook: called before module uninstallation

Like the "post_load" manifest option, the values for these hooks
must be a string containing the name of a method available at the
module root.
The signatures of these functions are:
 - (cr) for pre_init_hook
 - (cr, registry) for post_init_hook and uninstall_hook

[1] https://bugs.launchpad.net/openobject-server/+bug/1314680

openerp/modules/graph.py

@@ -3,7 +3,7 @@
 #
 #    OpenERP, Open Source Management Solution
 #    Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
-#    Copyright (C) 2010-2011 OpenERP s.a. (<http://openerp.com>).
+#    Copyright (C) 2010-2014 OpenERP s.a. (<http://openerp.com>).
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU Affero General Public License as
@@ -149,7 +149,14 @@ class Graph(dict):
             level += 1
 
 
-class Singleton(object):
+class Node(object):
+    """ One module in the modules dependency graph.
+
+    Node acts as a per-module singleton. A node is constructed via
+    Graph.add_module() or Graph.add_modules(). Some of its fields are from
+    ir_module_module (setted by Graph.update_from_db()).
+
+    """
     def __new__(cls, name, graph, info):
         if name in graph:
             inst = graph[name]
@@ -160,22 +167,13 @@ class Singleton(object):
             graph[name] = inst
         return inst
 
-
-class Node(Singleton):
-    """ One module in the modules dependency graph.
-
-    Node acts as a per-module singleton. A node is constructed via
-    Graph.add_module() or Graph.add_modules(). Some of its fields are from
-    ir_module_module (setted by Graph.update_from_db()).
-
-    """
-
     def __init__(self, name, graph, info):
         self.graph = graph
         if not hasattr(self, 'children'):
             self.children = []
         if not hasattr(self, 'depth'):
             self.depth = 0
+        self.info = info or {}
 
     def add_child(self, name, info):
         node = Node(name, self.graph, info)
@@ -189,7 +187,7 @@ class Node(Singleton):
         return node
 
     def __setattr__(self, name, value):
-        super(Singleton, self).__setattr__(name, value)
+        super(Node, self).__setattr__(name, value)
         if name in ('init', 'update', 'demo'):
             tools.config[name][self.name] = 1
             for child in self.children:

openerp/modules/loading.py

@@ -148,6 +148,13 @@ def load_module_graph(cr, graph, status=None, perform_checks=True, skip_modules=
         migrations.migrate_module(package, 'pre')
         load_openerp_module(package.name)
 
+        new_install = package.installed_version is None
+        if new_install:
+            py_module = sys.modules['openerp.addons.%s' % (module_name,)]
+            pre_init = package.info.get('pre_init_hook')
+            if pre_init:
+                getattr(py_module, pre_init)(cr)
+
         models = registry.load(cr, package)
 
         loaded_modules.append(package.name)
@@ -181,6 +188,11 @@ def load_module_graph(cr, graph, status=None, perform_checks=True, skip_modules=
 
             migrations.migrate_module(package, 'post')
 
+            if new_install:
+                post_init = package.info.get('post_init_hook')
+                if post_init:
+                    getattr(py_module, post_init)(cr, registry)
+
             registry._init_modules.add(package.name)
             # validate all the views at a whole
             registry['ir.ui.view']._validate_module_views(cr, SUPERUSER_ID, module_name)
@@ -401,10 +413,17 @@ def load_modules(db, force_demo=False, status=None, update_module=False):
         if update_module:
             # Remove records referenced from ir_model_data for modules to be
             # removed (and removed the references from ir_model_data).
-            cr.execute("SELECT id FROM ir_module_module WHERE state=%s", ('to remove',))
-            mod_ids_to_remove = [x[0] for x in cr.fetchall()]
-            if mod_ids_to_remove:
-                registry['ir.module.module'].module_uninstall(cr, SUPERUSER_ID, mod_ids_to_remove)
+            cr.execute("SELECT name, id FROM ir_module_module WHERE state=%s", ('to remove',))
+            modules_to_remove = dict(cr.fetchall())
+            if modules_to_remove:
+                pkgs = reversed([p for p in graph if p.name in modules_to_remove])
+                for pkg in pkgs:
+                    uninstall_hook = pkg.info.get('uninstall_hook')
+                    if uninstall_hook:
+                        py_module = sys.modules['openerp.addons.%s' % (pkg.name,)]
+                        getattr(py_module, uninstall_hook)(cr, registry)
+
+                registry['ir.module.module'].module_uninstall(cr, SUPERUSER_ID, modules_to_remove.values())
                 # Recursive reload, should only happen once, because there should be no
                 # modules to remove next time
                 cr.commit()