I have a model that contains a ManyToManyField. It looks like this..
applicable_events = models.ManyToManyField(Event)
I am trying to basically search using something like this:
if 'Video' in prop.applicable_events.all():
print("here")
But it isn't fully working as I expected. I want it to search that applicable_event (which is another model). The applicable_event model contains a field named 'name' which I am trying to search against.
If I do something like this
print(prop.applicable_events.all().filter(name=cur_event))
It prints
<QuerySet [<Event: Video Sign In Started>]>
So basically I am trying to find out if the string 'Video' is contained in that.
You can search if such event exists with:
if prop.applicable_events.filter(name__icontains='Video').exists():
# …
pass
or if you want an exact name match:
if prop.applicable_events.filter(name='Video').exists():
# …
pass
The reason 'Video' in prop.applicable_events.all() does not work is because that is a QuerySet (a collection) of Events, a string like 'Video' is not the same as an Event with that name, and definitely not if 'Video' is a substring of the name.
Related
i want to show related posts by tag name However i got the error " get() returned more than one Tag -- it returned 2!"
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(Comment.objects.filter(post=post, statusc=2))
tag=get_object_or_404(Tag,post=post)
related_item=Post.objects.filter(tag__tag_name__icontains=tag.tag_name,status=2).order_by('-created_date').distinct()[:3]
You can just query like:
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(comments)
related_items = Post.objects.filter(
tag__post=post
).order_by('-created_date').distinct()[:3]
# ...
Or if you want to exclude the current post:
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(comments)
related_items = Post.objects.exclude(pk=post.pk).filter(
tag__post=pos
).order_by('-created_date').distinct()[:3]
# ...
It is also better to perform a len(..) on the comments, since that will result in making a query to fetch the comments, whereas using two separate queries, will hit the database twice.
As per documentation, get() is used for retrieving 1 item. If there are multiple items, here there could be multiple tags used in single Post, it will throw error.
So, you can change it like this:
tags=Tag.objects.filter(post=post)
related_item=Post.objects.filter(tag__in=tags,status=2).order_by('-created_date').distinct()[:3]
I was wondering what is the correct approach,
Do I create HiddenInput fields in my ModelForm and from the
View I pass in the primaryKey for the models I am about to edit into
the hiddenInput fields and then grab those hiddenInput fields from
the AJAX script to use it like this?
item.load(
"/bookmark/save/" + hidden_input_field_1,
null,
function () {
$("#save-form").submit(bookmark_save);
}
);
Or is there is some more clever way of doing it and I have no idea?
Thanks
It depends upon how you want to implement.
The basic idea is to edit 1. you need to get the existing instance, 2. Save provided information into this object.
For #1 you can do it multiple ways, like passing ID or any other primary key like attribute in url like http://myserver/edit_object/1 , Or pass ID as hidden input then you have to do it through templates.
For #2, I think you would already know this. Do something like
inst = MyModel.objects.get(id=input_id) # input_id taken as per #1
myform = MyForm(request.POST, instance=inst)
if myform.is_valid():
saved_inst = myform.save()
I just asked in the django IRC room and it says:
since js isn't processed by the django template engine, this is not
possible.
Hence the id or the object passed in from django view can't be accessed within AJAX script.
I want to serialize a QuerySet that contains an extra statement:
region_list = Region.objects.extra(select={ 'selected': 'case when id = %s then 1 else 0 end' % (new_region.id)}).all()
I use the statement below to serialize
return HttpResponse(serializers.serialize('json', region_list), mimetype='application/json')
But when I obtain the json results in the browser, only the fields of the Region model appears, the selected field dissapear.
How can I fix that?
One slightly longwinded solution would be to to dump the objects to JSON via django-piston's JSONEmitter class. When you register your Region model with piston, you can say what fields to include, and mention 'selected' there, and then use your annotation to make sure that the queryset used in the piston handler contains all the info you want.
Or just look at how piston does it and, if you don't want all of piston, just mimic the bits you do.
I want to use django's admin filter on the list page.
The models I have are something like this:
class Location(model):
name = CharField()
class Inquiry(Model):
name = CharFiled()
location = ManyToManyField(Location)
Now I want to filter Inquiries, to display only those that contain relation to specific Location object. If I use
class InqAdmin(ModelAdmin):
list_filter = ['location', ]
admin.site.register(Inquiry, InqAdmin)
the admin page displays me the list of all Locations and allows to filter.
What I would like to get, is to get list of only those locations that have some Inquiries in relation to them (so I don't ever get the empty list result after filtering).
How can this be done?
You could create a custom manager for Locations that only returns Locations that have an Inquiry associated with them. If you make this the default manager, the admin will use it.
Only caveat is that you'll need create another manager that returns all Locations and use that in the rest of your app whenever you want to retrieve Locations that don't have an associated Inquiry.
The managers section in the Django docs is quite good, and should be all you need to get this set up.
EDIT:
sienf brings up a good point. Another way to accomplish this would be to define a subclass of django.contrib.admin.SimpleListFilter, and write the queryset method to filter out Inquiries with empty Locations. See https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.list_filter
Given the following models (cut down for understanding):
class Venue(models.Model):
name = models.CharField(unique=True)
class Band(models.Model):
name = models.CharField(unique=True)
class Event(models.Model):
name = models.CharField(max_length=50, unique=True)
bands = models.ManyToManyField(Band)
venue = models.ForeignKey(Venue)
start = models.DateField()
end = models.DateField()
The admin area works great for what I'm doing, but I'd like to open the site up a bit so that certain users can add new Events. For the public portions, I have several "administrative" fields on these models that I don't want the public to see (which is easy enough to fix).
My specific problem, though, is changing the display of the ManyToMany selections when creating a new Event. Because the number of Bands possible to list for an event should not be sent along as a multiselect box, I'd like to use an AutoComplete that handles multiples (like the Tags box, here on StackOverflow!).
I have this part working, and it correctly fills in a hidden input with the Band.id's separated by commas for a value. However, I can't understand how to put together letting Django do the validation using the ModelForms, and somehow also validating the 'Bands' selection.
Ideally, I want to auto-complete like the tags here on StackOverflow, and send along the selected Bands ID's in some kind of Delimited string - all while letting Django validate that the bands passed exist, etc, as if I left the annoying multi-select list in place.
Do I have to create my own Auto-Complete Field type for a form or model, and use that? Is there something else I'm overlooking?
I have seen some existing AutoComplete widgets, but I'd really-really-really like to use my own Autocomplete code, since it's already set up, and some of them look a bit convoluted.
There was a lot more text/explanation here, but I cut back because I'm avoiding Wall Of Text. If I left important stuff out, let me know.
It's a little hard to say without knowing exactly what your autocomplete code is doing, but as long as it is sending the ids of the bands like they would be sent with the <select>, the ModelForm should validate them as usual.
Basically, your POST string should look like:
name=FooBar2009&bands=1&bands=3&bands=4&venue=7&start=...
The easiest way to do this might be to use Javascript to add (and remove) a hidden input field for each band entered with the name band and the id of the band as the value. Then, when the user submits the form, the browser will take care of posting the right stuff, and the ModelForm will validate it.
Using the annointed jquery autocomplete plugin,
On the client-side I have something like this:
jQuery("#id_tags").autocomplete('/tagging_utils/autocomplete/tasks/task/', {
max: 10,
highlight: false,
multiple: true,
multipleSeparator: " ",
scroll: true,
scrollHeight: 300,
matchContains: true,
autoFill: true,
});
So, I have a view that returns when I type in a:
http://skyl.org/tagging_utils/autocomplete/tasks/task/?q=a&limit=10×tamp=1259652876009
You can see the view that serves that here:
http://github.com/skyl/skyl.org/blob/master/apps/tagging_utils/views.py
Now, it's going to be a little tricky .. you might except the POST, then in the clean method of the field try to .get() based on the strings and raise a form validation error if you can't get it ... right, name = ... unique=True .. so something like (off the top of my head) ... :
def clean_bands(self):
return Band.objects.filter( name__in = self.cleaned_data['bands'].split(' ') )
You could also check each string and raise a form error if there are no bands by that name .. not sure that the clean method should return a qs. Let me know if this helps and you want me to keep going/clarify.