# this is the abstract interface for Plugin instances # so it should be specialized in real plugin classes # like e.g. plugins.simplelist.SimpleList import json from django.template.loader import render_to_string from engine.prelude import Prelude # set to # . False : silent # [ 'SliceList', 'TabbedView' ] : to debug these classes # True : to debug all slices DEBUG= [ 'SliceList' ] class Plugin: uid=0 def __init__ (self, visible=True, hidable=True, hidden_by_default=False, **settings): # xxx should generate some random id self.uuid=Plugin.uid Plugin.uid += 1 self.visible=visible self.hidable=hidable self.hidden_by_default=hidden_by_default # we store as a dictionary the arguments passed to constructor # e.g. SimpleList (list=[1,2,3]) => _settings = { 'list':[1,2,3] } # our own settings are not made part of _settings but could be.. self._settings=settings if self.need_debug(): print "Plugin.__init__ Created plugin with settings %s"%self._settings.keys() # subclasses might handle some fields in their own way, # in which case this call is needed to capture that setting # see e.g. SimpleList or SliceList for an example of that def add_to_settings (self, setting_name): self._settings[setting_name]=getattr(self,setting_name) def classname (self): try: return self.__class__.__name__ except: return 'Plugin' # shorthands to inspect _settings def get_setting (self, setting, default=None): if setting not in self._settings: return default else: return self._settings[setting] def is_visible (self): return self.visible def is_hidable (self): return self.hidable def is_hidden_by_default (self): return self.hidden_by_default ########## def need_debug (self): if not DEBUG: return False if DEBUG is True: return True else: return self.classname() in DEBUG # returns the html code for that plugin # in essence, wraps the results of self.render_content () def render (self, request): uuid = self.uuid classname = self.classname() # initialize prelude placeholder self._init_request (request) # call render_content plugin_content = self.render_content (request) # expose _settings in json format to js settings_json = json.dumps (self._settings, separators=(',',':')) result = render_to_string ('plugin.html', {'uuid':uuid, 'classname':classname, 'visible':self.is_visible(), 'hidable':self.is_hidable(), 'hidden':self.is_hidden_by_default(), 'plugin_content' : plugin_content, 'settings_json' : settings_json, }) # handle requirements() if defined on this class try: self.handle_requirements (request, self.requirements()) except AttributeError: # most likely the object does not have that method defined, which is fine pass except: import traceback traceback.print_exc() pass return result # you may redefine this completely, but if you don't we'll just use methods # . template() to find out which template to use, and # . render_env() to compute a dictionary to pass along to the templating system def render_content (self, request): """Should return an HTML fragment""" template = self.template() env=self.render_env(request) if not isinstance (env,dict): raise Exception, "%s.render_env returns wrong type"%self.classname() # expose this class's settings to the template # xxx we might need to check that this does not overwrite env.. env.update(self._settings) result=render_to_string (template, env) if self.need_debug(): print "%s.render_content: BEG --------------------"%self.classname() print "template=%s"%template print "env=%s"%env.keys() # print result print "%s.render_content: END --------------------"%self.classname() return result #################### requirements/prelude management def _init_request (self, request): if not hasattr (request, 'plugin_prelude'): # include css/plugins.css request.plugin_prelude=Prelude(css_files='css/plugin.css') def inspect_request (self, request, message): has=hasattr(request,'plugin_prelude') get=getattr(request,'plugin_prelude','none-defined') print "INSPECT (%s), hasattr %s, getattr %s"%(message,has,get) # can be used directly in render_content() def add_js_files (self, request, files): self._init_request (request) request.plugin_prelude.add_js_files (files) def add_css_files (self, request, files): self._init_request (request) request.plugin_prelude.add_css_files (files) def add_js_chunks (self, request, chunks): self._init_request (request) request.plugin_prelude.add_js_chunks (chunks) def add_css_chunks (self, request, chunks): self._init_request (request) request.plugin_prelude.add_css_chunks (chunks) # or from the result of self.requirements() def handle_requirements (self, request, d): for (k,v) in d.iteritems(): if self.need_debug(): print "%s: handling requirement %s"%(self.classname(),v) method_name='add_'+k method=Plugin.__dict__[method_name] method(self,request,v) ######################################## abstract interface def title (self): return "you should redefine title()" # your plugin is expected to implement either # (*) def render_content(self, request) -> html fragment # -- or -- # (*) def template(self) -> filename # relative to STATIC # (*) def render_env (self, request) -> dict # this is the variable->value association used to render the template # in which case the html template will be used # if you see this string somewhere your template() code is not kicking in def template (self): return "undefined_template" def render_env (self, request): return {} # # tell the framework about requirements (for the document
) # # the notion of 'Media' in django provides for medium-dependant # # selection of css files # # as a first attempt however we keep a flat model for now # # can use one string instead of a list or tuple if needed, # # see requirements.py for details # def requirements (self): # return { 'js_files' : [], # a list of relative paths for js input files # 'css_files': [], # ditto for css, could have been a dict keyed on # # media instead # 'js_chunk' : [], # (lines of) verbatim javascript code # 'css_chunk': [], # likewise for css scripts # }