CODEWITHSUNDEEP
django
user2908926
user2908926

Reputation: 205

Passing a variable back to a template and updating a dropdown box value

I have a blog and would like to add a post_type variable which will be a dropdown on the webpage.

I have added post_type to my Post model as a Charfield. And setup the dropdown in the template. (this might not be the best way to do this)

It works when I'm creating a Post and also when I edit the post, if I change the dropdown value, the new value is saved. The problem I'm having is when I'm editing a post, I can't get the value to be selected in the dropdown.

I think the html tag for the value in the dropdown needed to be market as Selected but I cant figure out how to do this. I'd really appreciate the help if someone can point me in the right direction.

Upvotes: 0

Views: 208

Answers (1)

Ben Boyer
Ben Boyer

Reputation: 1234

The most simple way will be add list of choice to your charfield in the model.

model.py

class BlogPost(models.Model):
    POST_TYPE_CHOICES = (
        ('cooking', 'Cooking'),
        ('story','Amazing Stories'),
    )
    #other fields here
    post_type = models.CharField(choices=POST_TYPE_CHOICES, max_length=50)

Then if you create a ModelForm using this model the default layout in the template will be a dropdownlist.

from the doc :

choices

Field.choices

An iterable (e.g., a list or tuple) consisting itself of iterables of exactly two items (e.g. [(A, B), (A, B) ...]) to use as choices for this field. If choices are given, they’re enforced by model validation and the default form widget will be a select box with these choices instead of the standard text field.

EDITED the 20/02:

You need to pass the instance inside your view (I assume you are not using classbased view).

So you should have some thing like this:

def edit_post(request, post_id):
    #try to get the instance of the post you need to edit
    post_instance = get_object_or_404(Post, id = post_id)
    #get your form and pass it the current Post instance
    form = EditPostForm(request.POST or None, instance=post_instance)
    #validate your form
    if form.is_valid():
        #if using ModelForm the database will be saved as well 
        form.save()
    #then render your template with the form
    return render(request, "edit_post.html", {'form': form})

Then you should use the {{form.field_name}} notation in your template and see the curent value with the dropdown without problem.

Upvotes: 1

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