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.page import Page
10 from engine.prelude import Prelude
15 # . [ 'SliceList', 'TabbedView' ] : to debug these classes
16 # . True : to debug all plugin
19 #DEBUG= [ 'SliceList' ]
21 # decorator to deflect calls on Plugin to its Prelude through self.page.prelude
22 def to_prelude (method):
23 def actual (self, *args, **kwds):
24 prelude_method=Prelude.__dict__[method.__name__]
25 return prelude_method(self.page.prelude,*args, **kwds)
30 # using a simple incremental scheme to generate domids for now
31 # we just need this to be unique in a page
37 return "plugin-%d"%Plugin.domid
42 # . page: the context of the request being served
43 # . title: is used visually for displaying the widget
45 # . togglable: whether it can be turned on and off (like PleKitToggle)
46 # . toggled: if togglable, what's the initial status
47 # . visible: if not set the plugin does not show up at all
48 # (not quite sure what this was for)
50 # . domid: created internally, but can be set at creation time if needed
51 # useful for hand-made css, or for selecting an active plugin in a composite
52 # . rank: this is for plugins sons of a composite plugin
54 # any other setting can also be set when creating the object, like
56 # which will result in 'foo' being accessible to the template engine
58 def __init__ (self, page, title, domid=None,
59 visible=True, togglable=True, toggled=True, **settings):
62 # callers can provide their domid for css'ing
63 if not domid: domid=Plugin.newdomid()
65 self.classname=self._py_classname()
66 self.plugin_classname=self._js_classname()
68 self.togglable=togglable
70 # what comes from subclasses
71 for (k,v) in settings.iteritems():
73 if self.need_debug(): print "%s init - subclass setting %s"%(self.classname,k)
76 print "%s init dbg .... BEG"%self.classname
77 for (k,v) in self.__dict__.items(): print "dbg %s:%s"%(k,v)
78 print "%s init dbg .... END"%self.classname
79 # do this only once the structure is fine
80 self.page.record_plugin(self)
82 def _py_classname (self):
83 try: return self.__class__.__name__
84 except: return 'Plugin'
86 def _js_classname (self):
87 try: return self.plugin_classname ()
88 except: return self._py_classname()
91 def need_debug (self):
92 if not DEBUG: return False
93 if DEBUG is True: return True
94 else: return self.classname in DEBUG
96 def setting_json (self, setting):
97 # TMP: js world expects plugin_uuid
98 if setting=='plugin_uuid':
100 elif setting=='query_uuid':
101 try: value=self.query.uuid
102 except: return '%s:"undefined"'%setting
104 value=getattr(self,setting,None)
105 if not value: value = "unknown-setting-%s"%setting
106 # first try to use to_json method (json.dumps not working on class instances)
107 try: value_json=value.to_json()
108 except: value_json=json.dumps(value,separators=(',',':'))
109 return "%s:%s"%(setting,value_json)
111 # expose in json format to js the list of fields as described in json_settings_list()
112 # and add plugin_uuid: domid in the mix
113 # NOTE this plugin_uuid thing might occur in js files from joomla/js, ** do not rename **
114 def settings_json (self):
116 result += ",".join([ self.setting_json(setting) for setting in self.json_settings_list() ])
120 # as a first approximation, only plugins that are associated with a query
121 # need to be prepared for js - others just get displayed and that's it
122 def is_asynchroneous (self):
123 return 'query' in self.__dict__
125 # returns the html code for that plugin
126 # in essence, wraps the results of self.render_content ()
127 def render (self, request):
128 # call render_content
129 plugin_content = self.render_content (request)
130 # shove this into plugin.html
132 env ['plugin_content']= plugin_content
133 env.update(self.__dict__)
134 result = render_to_string ('plugin.html',env)
136 # export this only for relevant plugins
137 if self.is_asynchroneous():
138 env ['settings_json' ] = self.settings_json()
139 # compute plugin-specific initialization
140 js_init = render_to_string ( 'plugin-setenv.js', env )
141 self.add_js_chunks (js_init)
143 # interpret the result of requirements ()
144 self.handle_requirements (request)
148 # you may redefine this completely, but if you don't we'll just use methods
149 # . template_file() to find out which template to use, and
150 # . template_env() to compute a dictionary to pass along to the templating system
151 def render_content (self, request):
152 """Should return an HTML fragment"""
153 template = self.template_file()
154 env=self.template_env(request)
155 if not isinstance (env,dict):
156 raise Exception, "%s.template_env returns wrong type"%self.classname
157 result=render_to_string (template, env)
158 if self.need_debug():
159 print "%s.render_content: BEG --------------------"%self.classname
160 print "template=%s"%template
161 print "env.keys=%s"%env.keys()
164 print "%s.render_content: END --------------------"%self.classname
167 # or from the result of self.requirements()
168 def handle_requirements (self, request):
170 d=self.requirements()
171 for (k,v) in d.iteritems():
172 if self.need_debug():
173 print "%s: handling requirement %s"%(self.classname,v)
174 # e.g. js_files -> add_js_files
176 method=Page.__dict__[method_name]
178 except AttributeError:
179 # most likely the object does not have that method defined, which is fine
183 traceback.print_exc()
186 #################### requirements/prelude management
187 # just forward to our prelude instance - see decorator above
189 def add_js_files (self):pass
191 def add_css_files (self):pass
193 def add_js_chunks (self):pass
195 def add_css_chunks (self):pass
197 ######################################## abstract interface
198 # your plugin is expected to implement either
199 # (*) def render_content(self, request) -> html fragment
201 # (*) def template_file (self) -> filename
203 # (*) def template_env (self, request) -> dict
204 # this is the variable->value association used to render the template
205 # in which case the html template will be used
207 # if you see this string somewhere your template_file() code is not kicking in
208 def template_file (self): return "undefined_template"
209 def template_env (self, request): return {}
211 # # tell the framework about requirements (for the document <header>)
212 # # the notion of 'Media' in django provides for medium-dependant
213 # # selection of css files
214 # # as a first attempt however we keep a flat model for now
215 # # can use one string instead of a list or tuple if needed,
216 # # see requirements.py for details
217 # def requirements (self):
218 # return { 'js_files' : [], # a list of relative paths for js input files
219 # 'css_files': [], # ditto for css, could have been a dict keyed on
221 # 'js_chunk' : [], # (lines of) verbatim javascript code
222 # 'css_chunk': [], # likewise for css scripts
225 # # for better performance
226 # # you can specify a list of keys that won't be exposed as json attributes
227 # def exclude_from_json (self): return []
229 # mandatory : define the fields that need to be exposed to json as part of
230 # plugin initialization
231 # mention 'domid' if you need plugin_uuid
232 # also 'query_uuid' gets replaced with query.uuid
233 def json_settings_list (self): return ['json_settings_list-must-be-redefined']
235 # might also define this one; see e.g. slicelist.py that piggybacks simplelist js code
236 # def plugin_classname (self):