On Thu, May 14, 2009 at 5:26 PM, Margie <margierogin...@yahoo.com> wrote: > > Sorry for the length of this - I hope someone knowledgable about ajax > has a minute to take a look, I've been working on it for awhile. > George - if you are reading this - this is my attempt to do the jquery/ > ajax that you recommended a few days back when I posted a more general > question. > > Ok - here's the high level: I have a Task model that contains an owner > field. In the admin change_list view for the task, I am am trying to > create a jquery ajax request that will override the queryset for the > task's owner field so that it contains the users returned by a GET > request to http://mysite.com/admin/taskmanager/task/get_owner_queryse > /<taskId>. > > In other words, I don't want the queryset for owner to contain all > Users in the system, I want it to just contain the users that are > specified in the task's 'resources' field, which is a ManyToMany > field. > > Note: all code is also at http://dpaste.com/44241 - more readable > there. > > I'm trying hard to leverage the admin interface, which I think will > work for me if I can just figure out how to configure it with some > spiffy jquery/ajax. > > I'm doing this by overriding formfield_for_foreignkey () so that it > uses a special OwnerSelectWidget for the 'owner' field, like this: > > > > def formfield_for_foreignkey(self, db_field, request, **kwargs): > if db_field.name == "owner": > kwargs["widget"] = OwnerSelectWidget() > return db_field.formfield(**kwargs) > return super(TaskAdmin, self).formfield_for_foreignkey > (db_field, request, **kwargs) > > My OwnerSelectWidget looks like this: > > class OwnerSelectWidget(widgets.Select): > > class Media: > css = {} > js = ( > 'js/jquery.js', > ) > > def render(self, name, value, attrs=None): > rendered = super(OwnerSelectWidget, self).render(name, value, > attrs) > return rendered + mark_safe(u''' > <script type="text/javascript"> > $('#id_%(name)s').mousedown(function() { > $.getJSON("get_owner_queryset/ > NEED_TASK_ID_HERE", > function(data) { > var options = ''; > for (var i = 0; i < > data.length; i++) { > /* set options based on > data - not quite sure how */ > $('#id_%(name)s').html > (options); > }) > }) > </script> > ''' % {'name': name, }) > > My code that services the GET is in my admin.py file and looks like > this: > > class TaskAdmin(admin.ModelAdmin): > > def __call__(self, request, url): > if url is None: > pass > else: > match = re.search('get_owner_queryset/(\d+)', url) > if match: > return self.getOwnerQuerySet(match.group(0)) > else: > return super(TaskAdmin, self).__call__(request, url) > > def getOwnerQuerySet(self, taskId): > task = Task.objects.get(taskId) > resourcesToReturn = task.resources.all() # resources are users > return HttpResponse(simplejson.dumps(resourcesToReturn), > mimetype='application/json') > > > I have a couple problems (so far that I know of). > > 1. In line 8 of the render() method, where I have NEED_TASK_ID_HERE, > I'm trying to figure out how I get the task id. It seems like at > this point in the code I don't have access to that. The id is > output as part of the change_list form, but it doesn't have an id > associated with it. What is the best approach to take? > > 2. In getOwnerQuerySet(), I don't think what I'm returning is > correct. When I play around in pdb and create a User queryset and > then try to call simplejson.dumps() on it: > resources = User.objects.all() > return HttpResponse(simplejson.dumps(resourcesToReturn), > mimtype='application/json') > I get the error: > > *** TypeError: [<User: buck>, <User: bob>] is not JSON serializable > > So I think I am not really returning the data correctly. And when I > run the app > this way, I get a 500 INTERNAL SERVER ERROR. > > 3. Once I do manage to return whatever it is that I'm supposed to > return (ie, question 2), I'm not quite sure what it is going to look > like when it gets back to the jquery callback function. I have a > little for loop in there, but I think I need to come up name/value > pairs. If the GET is returning a list of user names, where does the > value come from? > > > Ok - sorry for the length of this but I've been working for awhile now > on it and could really use some pointers from someone knowledgable out > there. I know there is doc on this simplejson stuff, but the first > time around, it's just hard to make sense of it all. > > Margie > > >
Re: your second question, you'll want to use django's built in serialization: http://docs.djangoproject.com/en/dev/topics/serialization/ This nicely handles django models, and you can select a subset of fields to include, etc. Instead of your simplejson call, you can use: serializers.serialize("json", resourcesToReturn) To take a stab at your third question, JSON is literally a bit of javascript syntax that gets evaluated (JavaScript Object Notation :). So from a serialized queryset you'll get (on the javascript side) a list of objects with field names / data. So {'foo':'bar'} would give you a javascript object (call it 'test'), and test.foo == 'bar'. In your code you should be able to access an object in your loop with: item = data[i] Then try item.fields.name (if your model field is "name", etc). It might be helpful to look at a serialized queryset in the shell to see how the JSON is structured. Colin --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
