1 # this is the abstract interface for Plugin instances
2 # so it should be specialized in real plugin classes
3 # like e.g. plugins.simplelist.SimpleList
7 from django.template.loader import render_to_string
9 from engine.prelude import Prelude
13 # [ 'SliceList', 'TabbedView' ] : to debug these classes
14 # True : to debug all slices
16 DEBUG= [ 'SliceList' ]
20 # using a simple incremental scheme to generate uuids for now
23 # xxx should generate some random id
32 # . title: is used visually for displaying the widget
33 # . name: a simple id suitable for forging css names
35 # . hidable: whether it can be turned on and off from the UI
36 # like e.g. PleKitToggle
37 # . hidden_by_default: if hidable, what's the initial status
38 # . visible: if not set the plugin does not show up at all,
39 # not quite sure what this was for
41 # . uuid: created internally
42 # . rank: this is for plugins sons of a composite plugin
44 # any other setting can also be set when creating the object, like
46 # which will result in 'foo' being accessible to the template engine
48 def __init__ (self, title, name,
49 visible=True, hidable=True, hidden_by_default=False, **settings):
50 # what is in this dictionary will get exposed to template and to javascript
51 self._settings=settings
54 self.add_to_settings ( ['title','name'] )
55 self.uuid=Plugin.newuuid()
58 self.hidden_by_default=hidden_by_default
59 self.add_to_settings( ['uuid','visible','hidable','hidden_by_default'] )
60 # we store as a dictionary the arguments passed to constructor
61 # e.g. SimpleList (list=[1,2,3]) => _settings = { 'list':[1,2,3] }
62 # our own settings are not made part of _settings but could be..
64 print "Plugin.__init__ Created plugin with settings %s"%self._settings.keys()
66 # subclasses might handle some fields in their own way,
67 # in which case this call is needed to capture that setting
68 # see e.g. SimpleList or SliceList for an example of that
69 def add_to_settings (self, setting_name_s):
70 if not isinstance (setting_name_s, list):
71 self._settings[setting_name_s]=getattr(self,setting_name_s)
73 for setting_name in setting_name_s:
74 self._settings[setting_name]=getattr(self,setting_name)
77 try: return self.__class__.__name__
78 except: return 'Plugin'
80 # shorthands to inspect _settings
81 def get_setting (self, setting, default=None):
82 if setting not in self._settings: return default
83 else: return self._settings[setting]
85 def is_visible (self): return self.visible
86 def is_hidable (self): return self.hidable
87 def is_hidden_by_default (self): return self.hidden_by_default
90 def need_debug (self):
91 if not DEBUG: return False
92 if DEBUG is True: return True
93 else: return self.classname() in DEBUG
95 # returns the html code for that plugin
96 # in essence, wraps the results of self.render_content ()
97 def render (self, request):
99 classname = self.classname()
100 # initialize prelude placeholder
101 self._init_request (request)
103 # call render_content
104 plugin_content = self.render_content (request)
105 # expose _settings in json format to js
106 settings_json = json.dumps (self._settings, separators=(',',':'))
108 result = render_to_string ('plugin.html',
110 'classname':classname,
111 'visible':self.is_visible(),
112 'hidable':self.is_hidable(),
113 'hidden':self.is_hidden_by_default(),
114 'plugin_content' : plugin_content,
115 'settings_json' : settings_json,
118 # handle requirements() if defined on this class
120 self.handle_requirements (request, self.requirements())
121 except AttributeError:
122 # most likely the object does not have that method defined, which is fine
126 traceback.print_exc()
131 # you may redefine this completely, but if you don't we'll just use methods
132 # . template_file() to find out which template to use, and
133 # . template_env() to compute a dictionary to pass along to the templating system
134 def render_content (self, request):
135 """Should return an HTML fragment"""
136 template = self.template_file()
137 env=self.template_env(request)
138 if not isinstance (env,dict):
139 raise Exception, "%s.template_env returns wrong type"%self.classname()
140 # expose this class's settings to the template
141 # xxx we might need to check that this does not overwrite env..
142 env.update(self._settings)
143 result=render_to_string (template, env)
144 if self.need_debug():
145 print "%s.render_content: BEG --------------------"%self.classname()
146 print "template=%s"%template
147 print "env=%s"%env.keys()
149 print "%s.render_content: END --------------------"%self.classname()
152 #################### requirements/prelude management
153 def _init_request (self, request):
154 if not hasattr (request, 'plugin_prelude'):
155 # include css/plugins.css
156 request.plugin_prelude=Prelude(css_files='css/plugin.css')
158 def inspect_request (self, request, message):
159 has=hasattr(request,'plugin_prelude')
160 get=getattr(request,'plugin_prelude','none-defined')
161 print "INSPECT (%s), hasattr %s, getattr %s"%(message,has,get)
163 # can be used directly in render_content()
164 def add_js_files (self, request, files):
165 self._init_request (request)
166 request.plugin_prelude.add_js_files (files)
167 def add_css_files (self, request, files):
168 self._init_request (request)
169 request.plugin_prelude.add_css_files (files)
170 def add_js_chunks (self, request, chunks):
171 self._init_request (request)
172 request.plugin_prelude.add_js_chunks (chunks)
173 def add_css_chunks (self, request, chunks):
174 self._init_request (request)
175 request.plugin_prelude.add_css_chunks (chunks)
177 # or from the result of self.requirements()
178 def handle_requirements (self, request, d):
179 for (k,v) in d.iteritems():
180 if self.need_debug():
181 print "%s: handling requirement %s"%(self.classname(),v)
183 method=Plugin.__dict__[method_name]
184 method(self,request,v)
186 ######################################## abstract interface
187 # your plugin is expected to implement either
188 # (*) def render_content(self, request) -> html fragment
190 # (*) def template_file(self) -> filename
192 # (*) def template_env (self, request) -> dict
193 # this is the variable->value association used to render the template
194 # in which case the html template will be used
196 # if you see this string somewhere your template_file() code is not kicking in
197 def template_file (self): return "undefined_template"
198 def template_env (self, request): return {}
200 # # tell the framework about requirements (for the document <header>)
201 # # the notion of 'Media' in django provides for medium-dependant
202 # # selection of css files
203 # # as a first attempt however we keep a flat model for now
204 # # can use one string instead of a list or tuple if needed,
205 # # see requirements.py for details
206 # def requirements (self):
207 # return { 'js_files' : [], # a list of relative paths for js input files
208 # 'css_files': [], # ditto for css, could have been a dict keyed on
210 # 'js_chunk' : [], # (lines of) verbatim javascript code
211 # 'css_chunk': [], # likewise for css scripts