Refactor plugin initialization and enablement

Move most plugin enablement and initialization code in plugin.py to
reduce code duplication and simplify and unifify plugin enablement
for all base plugin types (login, info, providers).

This patch breaks backwards compatibility as it changes how the list
of enabled plugins is stored in the database tables.

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Patrick Uiterwijk <puiterwijk@redhat.com>

1 files changed, 46 insertions, 70 deletions

diff --git a/ipsilon/login/common.py b/ipsilon/login/common.py
index ad09ce1..b394fa0 100755
--- a/ipsilon/login/common.py
+++ b/ipsilon/login/common.py
@@ -31,14 +31,13 @@ USERNAME_COOKIE = 'ipsilon_default_username'
 
 class LoginManagerBase(PluginConfig, PluginObject):
 
-    def __init__(self):
+    def __init__(self, *args):
         PluginConfig.__init__(self)
-        PluginObject.__init__(self)
+        PluginObject.__init__(self, *args)
+        self._root = None
         self._site = None
         self.path = '/'
-        self.next_login = None
         self.info = None
-        self.is_enabled = False
 
     def redirect_to_path(self, path):
         base = cherrypy.config.get('base.mount', "")
@@ -94,8 +93,9 @@ class LoginManagerBase(PluginConfig, PluginObject):
 
     def auth_failed(self, trans):
         # try with next module
-        if self.next_login:
-            return self.redirect_to_path(self.next_login.path)
+        next_login = self.next_login()
+        if next_login:
+            return self.redirect_to_path(next_login.path)
 
         # return to the caller if any
         session = UserSession()
@@ -117,62 +117,26 @@ class LoginManagerBase(PluginConfig, PluginObject):
     def get_tree(self, site):
         raise NotImplementedError
 
-    def enable(self, site):
-        if self.is_enabled:
-            return
+    def register(self, root, site):
+        self._root = root
+        self._site = site
 
-        if not self._site:
-            self._site = site
+    def next_login(self):
         plugins = self._site[FACILITY]
+        try:
+            idx = plugins.enabled.index(self.name)
+            item = plugins.enabled[idx + 1]
+            return plugins.available[item]
+        except (ValueError, IndexError):
+            return None
 
-        # configure self
-        if self.name in plugins['config']:
-            self.import_config(plugins['config'][self.name])
+    def on_enable(self):
 
         # and add self to the root
-        root = plugins['root']
-        root.add_subtree(self.name, self.get_tree(site))
-
-        # finally add self in login chain
-        prev_obj = None
-        for prev_obj in plugins['enabled']:
-            if prev_obj.next_login:
-                break
-        if prev_obj:
-            while prev_obj.next_login:
-                prev_obj = prev_obj.next_login
-            prev_obj.next_login = self
-        if not root.first_login:
-            root.first_login = self
-
-        plugins['enabled'].append(self)
-        self.is_enabled = True
-        self._debug('Login plugin enabled: %s' % self.name)
+        self._root.add_subtree(self.name, self.get_tree(self._site))
 
         # Get handle of the info plugin
-        self.info = root.info
-
-    def disable(self, site):
-        if not self.is_enabled:
-            return
-
-        plugins = self._site[FACILITY]
-
-        # remove self from chain
-        root = plugins['root']
-        if root.first_login == self:
-            root.first_login = self.next_login
-        elif root.first_login:
-            prev_obj = root.first_login
-            while prev_obj.next_login != self:
-                prev_obj = prev_obj.next_login
-            if prev_obj:
-                prev_obj.next_login = self.next_login
-        self.next_login = None
-
-        plugins['enabled'].remove(self)
-        self.is_enabled = False
-        self._debug('Login plugin disabled: %s' % self.name)
+        self.info = self._root.info
 
 
 class LoginPageBase(Page):
@@ -207,8 +171,9 @@ class LoginFormBase(LoginPageBase):
 
     def create_tmpl_context(self, **kwargs):
         next_url = None
-        if self.lm.next_login is not None:
-            next_url = '%s?%s' % (self.lm.next_login.path,
+        next_login = self.lm.next_login()
+        if next_login:
+            next_url = '%s?%s' % (next_login.path,
                                   self.trans.get_GET_arg())
 
         cookie = SecureCookie(USERNAME_COOKIE)
@@ -253,31 +218,42 @@ class Login(Page):
     def __init__(self, *args, **kwargs):
         super(Login, self).__init__(*args, **kwargs)
         self.cancel = Cancel(*args, **kwargs)
-        self.first_login = None
         self.info = Info(self._site)
 
-        loader = PluginLoader(Login, FACILITY, 'LoginManager')
-        self._site[FACILITY] = loader.get_plugin_data()
-        plugins = self._site[FACILITY]
+        plugins = PluginLoader(Login, FACILITY, 'LoginManager')
+        plugins.get_plugin_data()
+        self._site[FACILITY] = plugins
 
-        available = plugins['available'].keys()
+        available = plugins.available.keys()
         self._debug('Available login managers: %s' % str(available))
 
-        plugins['root'] = self
-        for item in plugins['whitelist']:
-            self._debug('Login plugin in whitelist: %s' % item)
-            if item not in plugins['available']:
+        for item in plugins.available:
+            plugin = plugins.available[item]
+            plugin.register(self, self._site)
+
+        for item in plugins.enabled:
+            self._debug('Login plugin in enabled list: %s' % item)
+            if item not in plugins.available:
                 continue
-            plugins['available'][item].enable(self._site)
+            plugins.available[item].enable()
 
     def add_subtree(self, name, page):
         self.__dict__[name] = page
 
+    def get_first_login(self):
+        plugin = None
+        plugins = self._site[FACILITY]
+        if plugins.enabled:
+            first = plugins.enabled[0]
+            plugin = plugins.available[first]
+        return plugin
+
     def root(self, *args, **kwargs):
-        if self.first_login:
+        plugin = self.get_first_login()
+        if plugin:
             trans = self.get_valid_transaction('login', **kwargs)
             redirect = '%s/login/%s?%s' % (self.basepath,
-                                           self.first_login.path,
+                                           plugin.path,
                                            trans.get_GET_arg())
             raise cherrypy.HTTPRedirect(redirect)
         return self._template('login/index.html', title='Login')
@@ -312,5 +288,5 @@ class Cancel(Page):
 class LoginMgrsInstall(object):
 
     def __init__(self):
-        pi = PluginInstaller(LoginMgrsInstall)
+        pi = PluginInstaller(LoginMgrsInstall, FACILITY)
         self.plugins = pi.get_plugins()