1 files changed, 149 insertions, 0 deletions
diff --git a/webapp/django/contrib/databrowse/sites.py b/webapp/django/contrib/databrowse/sites.py
new file mode 100644
index 0000000000..9ef35dbc1c
--- /dev/null
+++ b/webapp/django/contrib/databrowse/sites.py
@@ -0,0 +1,149 @@
+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.__class__.__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.__class__.__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()}