from django import http from django.db import models from django.contrib.databrowse.datastructures import EasyModel from django.shortcuts import render_to_response from django.utils.safestring import mark_safe class AlreadyRegistered(Exception): pass class NotRegistered(Exception): pass class DatabrowsePlugin(object): def urls(self, plugin_name, easy_instance_field): """ Given an EasyInstanceField object, returns a list of URLs for this plugin's views of this object. These URLs should be absolute. Returns None if the EasyInstanceField object doesn't get a list of plugin-specific URLs. """ return None def model_index_html(self, request, model, site): """ Returns a snippet of HTML to include on the model index page. """ return '' def model_view(self, request, model_databrowse, url): """ Handles main URL routing for a plugin's model-specific pages. """ raise NotImplementedError class ModelDatabrowse(object): plugins = {} def __init__(self, model, site): self.model = model self.site = site def root(self, request, url): """ Handles main URL routing for the databrowse app. `url` is the remainder of the URL -- e.g. 'objects/3'. """ # Delegate to the appropriate method, based on the URL. if url is None: return self.main_view(request) try: plugin_name, rest_of_url = url.split('/', 1) except ValueError: # need more than 1 value to unpack plugin_name, rest_of_url = url, None try: plugin = self.plugins[plugin_name] except KeyError: raise http.Http404('A plugin with the requested name does not exist.') return plugin.model_view(request, self, rest_of_url) def main_view(self, request): easy_model = EasyModel(self.site, self.model) html_snippets = mark_safe(u'\n'.join([p.model_index_html(request, self.model, self.site) for p in self.plugins.values()])) return render_to_response('databrowse/model_detail.html', { 'model': easy_model, 'root_url': self.site.root_url, 'plugin_html': html_snippets, }) class DatabrowseSite(object): def __init__(self): self.registry = {} # model_class -> databrowse_class self.root_url = None def register(self, model_or_iterable, databrowse_class=None, **options): """ Registers the given model(s) with the given databrowse site. The model(s) should be Model classes, not instances. If a databrowse class isn't given, it will use DefaultModelDatabrowse (the default databrowse options). If a model is already registered, this will raise AlreadyRegistered. """ databrowse_class = databrowse_class or DefaultModelDatabrowse if issubclass(model_or_iterable, models.Model): model_or_iterable = [model_or_iterable] for model in model_or_iterable: if model in self.registry: raise AlreadyRegistered('The model %s is already registered' % model.__name__) self.registry[model] = databrowse_class def unregister(self, model_or_iterable): """ Unregisters the given model(s). If a model isn't already registered, this will raise NotRegistered. """ if issubclass(model_or_iterable, models.Model): model_or_iterable = [model_or_iterable] for model in model_or_iterable: if model not in self.registry: raise NotRegistered('The model %s is not registered' % model.__name__) del self.registry[model] def root(self, request, url): """ Handles main URL routing for the databrowse app. `url` is the remainder of the URL -- e.g. 'comments/comment/'. """ self.root_url = request.path[:len(request.path) - len(url)] url = url.rstrip('/') # Trim trailing slash, if it exists. if url == '': return self.index(request) elif '/' in url: return self.model_page(request, *url.split('/', 2)) raise http.Http404('The requested databrowse page does not exist.') def index(self, request): m_list = [EasyModel(self, m) for m in self.registry.keys()] return render_to_response('databrowse/homepage.html', {'model_list': m_list, 'root_url': self.root_url}) def model_page(self, request, app_label, model_name, rest_of_url=None): """ Handles the model-specific functionality of the databrowse site, delegating to the appropriate ModelDatabrowse class. """ model = models.get_model(app_label, model_name) if model is None: raise http.Http404("App %r, model %r, not found." % (app_label, model_name)) try: databrowse_class = self.registry[model] except KeyError: raise http.Http404("This model exists but has not been registered with databrowse.") return databrowse_class(model, self).root(request, rest_of_url) site = DatabrowseSite() from django.contrib.databrowse.plugins.calendars import CalendarPlugin from django.contrib.databrowse.plugins.objects import ObjectDetailPlugin from django.contrib.databrowse.plugins.fieldchoices import FieldChoicePlugin class DefaultModelDatabrowse(ModelDatabrowse): plugins = {'objects': ObjectDetailPlugin(), 'calendars': CalendarPlugin(), 'fields': FieldChoicePlugin()}