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()}
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