Using Marius Gedminas's excellent blog post, I have created a custom traverser for a folder in my site.
This allows me to show: http://foo.com/folder/random_id
Instead of: http://foo.com/folder/object.html?id=random_id
The configuration side works great, I can catch the random_ids and search through my messages for the correct one, ready to display.
My problem is that I'm unsure how to then display the data via my usual page templates - at the TODO point in his original code ;)
if name == 'mycalendar':
mycalendar = ... # TODO: do something to get the appropriate object
return mycalendar
Usually I'd use something similar to:
class Test(BrowserPage):
template = ViewPageTemplateFile('atest.pt')
def __call__(self):
return self.template()
But I can't work out how to do this correctly in the context of the custom traversal.
UPDATE: To be clear I want to avoid adding anything else to the url (No: http://foo.com/folder/random_id/read).
I don't need the view to be available via any other address (No: http://foo.com/folder/read)
The ZCML for the view I'd like to use is:
<browser:page
for="foo.interfaces.IFooFolderContainer"
name="read"
template="read.pt"
permission="zope.ManageContent"
/>
I'm guessing (on further advice), something along the lines of:
return getMultiAdapter((mycalendar, self.request), IPageTemplate, name=u'read')
Or even a default view for the object type (a dict in this case) that's being returned:
<browser:page
for="dict"
name="read"
template="read.pt"
permission="zope.ManageContent"
/>
It would be easier to answer your question if you showed what your custom traverser is doing.
Essentially, you want something like this:
def publishTraverse(self, request, name):
if name in self.context:
return MyMessageView(self.context[name], request)
# fall back to views such as index.html
view = queryMultiAdapter((self.context, request), name=name)
if view is not None:
return view
# give up and return a 404 Not Found error page
raise NotFound(self.context, name, request)
where MyMessageView can be something as simple as
class MyMessageView(BrowserPage):
__call__ = ViewPageTemplateFile('read.pt')
Disclaimer: I'm not sure if the view you instantiate directly will be protected by a security wrapper; make sure your functional tests ensure anonymous users can't view messages if that's what you want.
If you end up at a proper object with your custom traverser, you can just tack on the template name and user "context" in that template. So http://foo.com/folder/random_id/my_template and in the template do the normal <h1 tal:content="context/title" /> stuff.
IIUC, what you want is to render the 'read' view when somebody requests /folder/random_id. If that's the case, all you need to do is make your traversal return an object (IFolderContent, maybe) representing a random_id and specify the 'view' page as the defaultView for IFolderContent.
The defaultView is needed because there's no view specified for the random_id object in your URL.
Related
Sorry if this is a noob question I am still learning. I have passed a variable from python code to a jinja2 HTML template to set up a URL, like this:
Delete
When this link is pressed it should run a query that deletes the entity with that ID. But when the link is pressed it goes to /delete/1827424298 for example, which results in a 404 error as the request handler doesn't exist.
I need to pass that ID back into my python code so it can run a method to delete the entity with that same ID. How do I go about doing this? Using webapp2 if that is important.
class DeleteRequestHandler(webapp2.RequestHandler):
def get():
template = template_env.get_template('myrequests.html')
context = {
'results': results.key.id()
}
self.response.out.write(template.render(context))
EDIT: I've added my delete handler - it is incomplete as I have yet to add the query to delete the entity. My thinking behind it so far is I can grab the results.key.id() from the jinja2 template and put it into results but I am not sure if this would work.
So I think what you're confused about is how to set up a route handler with a dynamic part to the URL. It's a shame that this is completely skipped over in the webapp2 tutorial, as it's a fundamental part of writing any web application. However, it is covered well in the guide to routing, which you should read.
At its simplest, it's just a matter of putting a regex in the route:
app = webapp2.WSGIApplication([
...
(r'/delete/(\d+)', MyDeleteHandler),
])
which will now route any URL of the form /delete/<number>/ to your deletion handler.
The ID that you pass in the URL will be the first positional argument to the handler method:
class MyDeleteHandler:
def get(self, item_id):
key = ndb.Key(MyModel, item_id) # or whatever
I have written what I hope to be a re-usable Django app, but I have a bit of a conundrum on how to make the post form handling flexible. The simplified version of my view code looks like:
def do_form(request, entity_id, template_name, success_url):
form = MyForm(request.POST or None)
if request.method =='POST':
if form.is_valid():
#do some business logic
return HttpResponseRedirect(finished_url)
return render_to_response(template_name,
{'form': form},
context_instance=RequestContext(request))
I have followed the advice in James Bennets book "Practical Django Projects" and so you can now configure the template and the success url in the url conf, so for example my url conf could look like this:
urlpatterns = patterns('myapp.views',
url(r'^do/(?P<entity_id>\d+)/$',
view = 'do_form',
name = 'do_form_view',
kwargs={'template_name':'form.html',
'success_url':'/finish/'},),
url(r'^finish/$',
view = 'finish',
name = 'finish_view')
)
This is all very well and good but when I have come to use this in my real world application I find myself in a situation that this form sits in the middle of some workflow, and I want the success url to be something like /continue/<workflow_id>/ , and the problem is that you can only have a hardcoded url in the url conf, and the workflow_id will vary every time I hit the do_form code.
Can any one suggest a way to get around this?
You can achieve that by changing the following..
in do_form() in views.py
change the return HttpResponseRedirect to
return HttpResponseRedirect('/continue/%s' %(workflowid))
And in urls.py, you can have
url(r'^continue/(?P<workflowid>\d+)/$',
view = 'continue',
name = 'continue_view')
and for the continue() view in views.py
def continue(request, workflowid=None):
...
This way.. whenever you access the url /continue/ without a number, workflowid will be equal to None. Every other time when you do have a workflowid attached for e.g. like /continue/23/ , then inside your continue() view you can access that id through the variable workflowid.
When you pass a hypothethical "flexible" success_url to a view, that view MUST supply the desired identifier. So if you mismatch the URL and the view, we can't avoid having a "breach of contract" between the two.
Therefore if we are to have flexible URLs, some kind of contract shall have to be enforced, and there will be no loss of generality if we do this through a special syntax for URLs:
'finished_url': '/finish/<workflow_id>/'
Then, of course, the view shall have to instantiate the variable through a string replacement to honor its side of the contract: instead of
return HttpResponseRedirect(finished_url)
you will have
return HttpResponseRedirect(finished_url.replace('<workflow_id>', WorkflowID))
This should keep things reasonably simple.
When reusing code, you will have to keep in mind that <workflow_id> is whatever that app uses to call workflow id, and that's why I use a complicated string such as workflow_id instead of id or maybe $1.
EDIT: I was going to add the code for the next step (intercepting workflow ID in argument of finish), but I see that keithxm23 beat me to the punch :-)
You can do it the same way people have been "overriding" Django's function-based generic views for years: simply wrap the view in another view:
def custom_do_form(request, entity_id, template_name, success_url):
template_name = some_method_to_get_template()
return do_form(request, entity_id, template_name, success_url)
I'd like to check a condition before each request and call different views.
How is that achieved?
One solution I can think of is adding something to subscriber NewRequest, but I am stuck:
#subscriber(NewRequest)
def new_request_subscriber(event):
if condition:
#what now?
#subscriber(NewRequest)
def new_request_subscriber(event):
if condition:
raise pyramid.httpexceptions.HTTPFound(location=somelocation) ## to issue a proper redirect
More info can be found here:
http://pyramid.readthedocs.org/en/latest/api/httpexceptions.html#pyramid.httpexceptions.HTTPFound
Well you've given very little information about the "condition" or what you mean by "call different views", so I'll assume you do not want to invoke a redirect but instead you want the application to think a different URL is being requested. To do that you can look at pyramid_rewrite, which is pretty handy for these things, or you can just change the request's path within the NewRequest subscriber, since it is invoked before Pyramid dispatches to a view.
if request.path == '/foo':
request.path = '/bar':
config.add_route('foo', '/foo') # never matches
config.add_route('bar', '/bar')
Yet another option to "check a condition ... and call different views" is to use custom view predicates
From Cris McDonough's blog post:
def example_dot_com_host(info, request):
if request.host == 'www.example.com:
return True
That's a custom predicate there. It returns True if the hostname is www.example.com. Here's how we use it:
#view_config(route_name='blogentry', request_method='GET')
def get_blogentry(request):
...
#view_config(route_name='blogentry', request_method='POST')
def post_blogentry(request):
...
#view_config(route_name='blogentry', request_method='GET',
custom_predicates=(example_dot_com_host,))
def get_blogentry_example_com(request):
...
#view_config(route_name='blogentry', request_method='POST',
custom_predicates=(example_dot_com_host,))
def post_blogentry_example_com(request):
...
However, for your particular problem (display a sign in page if user has no permission to view the page) a better way to achieve this would be to set up permissions for views so the framework raises an exception when user has no permission, and then register a custom view for that exception which will show a sign in form.
this is very specific to what I am trying to do so I start describing what it is:
a Pyramid app serving plots like http://localhost:6543/path/to/myplot/plot001.png
if the plot is not available another image is served (work.png)
another part is the deform view which provides a HTML form to enter the configuration for a plot like: http://localhost:6543/path/to/myplot/plot001.png?action=edit. Note here the query string "action=edit".
the configuration consists of datafile, templates etc.
the form has save (to save the config) and render buttons (http://localhost:6543/path/to/myplot/plot001.png?action=render). Rendering results into a png file which then is used in a static way.
I figured out all the pieces like rendering using Matplotlib etc. but I am new to Pyramid and Deform. I also have a working view that serves the plot from file. The deform form kind of works, too. At the moment it is unclear to me how to best structure the ULRs to distinguish the serve, edit and render usecases. I guess in Pyramid talk this means how to configure the routes for serve_view and edit_view.
__init__.py:
config.add_route('serve_route',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
config.add_route('edit_route',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
# can I use query strings like "?action=edit" here to distinguish the difference?
views.py:
#view_config(context=Root, route_name='serve_route')
def plot_view(context, request):
...
#view_config(context=Root, renderer='bunseki:templates/form.pt', route_name='edit_route')
def edit_view(request):
...
I the Pyramid manual I could not find reference how to set parameters in the route. I guess a pointer to some documentation or sample would be sufficient and I can figure out the details myself. Thank you!
There are two ways to do this depending on what you prefer for separating your code.
Put all of the logic into your view, separated by 'if' statements on request.GET.get('action').
config.add_route('plot', '/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
config.scan()
#view_config(route_name='plot')
def plot_view(request):
action = request.GET('action')
if action == 'edit':
# do something
return render_to_response('bunseki:templates/form.pt', {}, request)
# return the png
Register multiple views and delegate between them using Pyramid's view lookup mechanics.
config.add_route('plot', '/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
config.scan()
#view_config(route_name='plot')
def plot_image_view(request):
# return the plot image
#view_config(route_name='plot', request_param='action=edit',
renderer='bunseki:templates/form.pt')
def edit_plot_view(request):
# edit the plot
return {}
# etc..
Hope this helps. It's an excellent example of registering a single url pattern, and using different views for different types of requests on that url.
I'm not sure you can use contex=Root in that situation, but what you are asking for is probably the matchdict.
__init__.py:
config.add_route('serve_route',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
views.py:
#view_config(route_name='serve_route')
def plot_view(request):
project_name = request.matchdict['project_name']
action = request.params.get('action', None)
http://docs.pylonsproject.org/projects/pyramid/1.1/narr/urldispatch.html#matchdict
Edit:
If your question is more a general question regarding routing, you should create one route per action to keep the code of your view functions shorter and clearer. For example, if you want to edit and render, your routes could look something like this:
__init__.py:
config.add_route('render_plot',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
config.add_route('edit_plot',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}/edit')
views.py:
#view_config('render_plot')
def render(request):
pass
#view_config('edit_plot', renderer='bunseki:templates/form.pt')
def edit(request):
pass
A more effective way will be to specify the action in the url. And you can even serve different actions on the same route name or multiple.
config.add_route('serve_route', '/{project_name}/testruns/{testrun_name}/plots/{action}/{plot_name}.png')
views.py
#view_config(context=Root, route_name='serve_route', action='view')
def plot_view(request):
pass
Or with query string
`config.add_route('serve_route',
'/{project_name}/testruns/{testrun_name}/plots/{plot_name}.png')
views.py
#view_config(context=Root, route_name='serve_route')
def plot_view(request):
try:
action = getattr(self._request.GET, 'action')
except AttributeError:
raise
I have the following middleware class:
class CommonContextMiddleware:
def process_template_response(self, request, response):
# Get the context and top videos
context = response.context_data
...
# Add most_recent and most_viewed to the context...
context['most_recent'] = top_videos['most_recent'][:3]
context['most_viewed'] = top_videos['most_viewed'][:3]
# ...then continue rendering
return response
However, no matter what I put in the function, it's never being called. I presumed that this method would be called for every single template response generated, am I wrong?
Thanks in advance.
I assume when you're talking about "template response", you are actually returning a TemplateResponse from your Django view?
This isn't really the best place for this sort of thing. If you just want to add variables into every template context, the best place to do it is in a context processor.