I'd like a URL of the form:
... field1/eq/value1/field2/gt/value2/ ...
Where I want to filter the contents of the page in the view function based on an arbitrary number of fields (the names of which are not known in advance).
I've tried:
(r'^((?P<field>\w+)/(?P<op>[a-z]+)/(?P<value>\w+)/)*$', my_view)
But the keyword arguments are filled with the last set of three field/op/value to occur in the URL.
Is there any way that I could populate a list or dictionary based on a variable number of URl fields like this?
Or should I be doing this some completely different way?
Don't do this.
Use the query string. ?field,eq,value&field,gt,value will work out much better.
Related
Using a ListView Class-based-view, I am looping over the objects present in the database of a certain model in my HTML template, and, for instance, I can access an object's "body_text" attribute with the following syntax: {{object.body_text}}
What if I wanted to only show the first 20 characters of that "body_text" attribute in my HTML template?
How can I set that?
1st Method
Use the truncatechars filter in your HTML template.Truncates a string if it is longer than the specified number of characters. Truncated strings will end with a translatable ellipsis character (“…”).
{{object.body_text|truncatechars:20}}
Reference:
https://docs.djangoproject.com/en/dev/ref/templates/builtins/?from=olddocs#truncatechars
2nd Method
Use the slice filter in your HTML template.
{{object.body_text|slice:":20"}}
Referernce: https://docs.djangoproject.com/en/dev/ref/templates/builtins/#slice
Found it, eventually.
Use the |slice:":" filter in your HTML template.
For example, if you only want to display the first 10 characters of a given attribute, use:
{{object.body_text|slice:":10"}}
I'm wanting to pass information relating to orders into my template via an ajax call. The problem is that that I've got more than two values that I want to pass in.
Key: Email address
Values that pertain to each key that I want to pass in:
Invoice Date
Name
Phone number
I'm wondering what the best way to do this is. Does the dictionary value need to be a list?
eg.
order_dict[order.email] = ['order.invoice_date', 'order.name', 'order.phone']
If the dictionary value does need to be a list, how would I iterate over it in my template?
Thanks for your help!
Suppose I have a model Order, which has a column num -- an order number. Now I want to filter several rows from this model in admin view. Having 1 value, I do:
http://bla-bla-bla/admin/app/order/?num__exact=11534
How can I do this when I have several values?
Or should I use queryset()? How then I should send a list of values to request?
in should work, try this in the url
http://bla-bla-bla/admin/app/order/?num__in=11534,11535,11536
Don't forget that whatever you put in the query string has to be allowed for the admin interface. You can't put in filters that weren't defined there - ever since this security release https://www.djangoproject.com/weblog/2010/dec/22/security/
I normally use something like this "Tag.object.annotate(num_post=Count('post')).filter(num_post__gt=2)" to get tags with more than 2 posts. I want to get number of posts with a field value (e.g post.published=True) and annote over them so that I get tags with number of published posts bigger than some value. How would I do that?
Edit:
What I want is not filter over annotated objects. What I want is something like this: Tag.objects.annotate(num_post=Count("posts that have published field set to true!")). What I am trying to learn is, how to put post that have published field set to true in Count function.
You can just replace the 2 in ..._gt=2 with some other variable - for example, a variable that gets passed into the view, or a request.GET value, or similar.
Is that what you're trying to do?
I'm trying to do a django query, but with the possibility of several different WHERE parameters. So I was thinking of doing something like:
querystring = "subcat__id__in=[1,3,5]"
Listing.objects.filter(querystring)
Here Listing is defined in my model, and it contains the Many-To-Many field subcat. However, that raises a ValueError because filter doesn't accept a string as its argument. Is there a way in Python to have a string evaluated as just its contents rather than as a string? Something like a print statement that prints the value of the string inline rather than to the standard output.
By the way, the reason I don't just do
querystring = [1,3,5]
Listing.objects.filter(subcat__id__in=querystring)
is that I'm not always filtering for subcat__id, sometimes it's one or several other parameters, and I'd rather not have to write out a bunch of separate queries controlled by if statements. Any advice is much appreciated.
Perhaps...
filter_dict = {'subcat__id__in': [1,3,5]}
Listing.objects.filter(**filter_dict)
Listing.objects.filter(**{"subcat__id__in": ast.literal_eval("[1,3,5]")})