Django: Search form in Class Based ListView

Question

I am trying to realize a `Class Based ListView` which displays a selection of a table set. If the site is requested the first time, the dataset should be displayed. I would prefer a POST submission, but GET is also fine. That is a problem, which was easy to handle with `function based views`, however with class based views I have a hard time to get my head around. My problem is that I get a various number of error, which are caused by my limited understanding of the classed based views. I have read various documentations and I understand views for direct query requests, but as soon as I would like to add a form to the query statement, I run into different error. For the code below, I receive an `ValueError: Cannot use None as a query value`. What would be the best practise work flow for a class based ListView depending on form entries (otherwise selecting the whole database)? This is my sample code: models.py ``` class Profile(models.Model): name = models.CharField(_('Name'), max_leng…

Accepted Answer

I think your goal is trying to filter queryset based on form submission, if so, by using GET :

```
class ProfileSearchView(ListView)
    template_name = '/your/template.html'
    model = Person

def get_queryset(self):
        name = self.kwargs.get('name', '')
        object_list = self.model.objects.all()
        if name:
            object_list = object_list.filter(name__icontains=name)
        return object_list
```

Then all you need to do is write a `get` method to render template and context.

Maybe not the best approach. By using the code above, you no need define a Django form.

Here's how it works : Class based views separates its way to render template, to process form and so on. Like, `get` handles GET response, `post` handles POST response, `get_queryset` and `get_object` is self explanatory, and so on. The easy way to know what's method available, fire up a shell and type :

`from django.views.generic import ListView` if you want to know about `ListView`

and then type `dir(ListView)`. There you can see all the method defined and go visit the source code to understand it. The `get_queryset` method used to get a queryset. Why not just define it like this, it works too :

```
class FooView(ListView):
    template_name = 'foo.html'
    queryset = Photo.objects.all()  # or anything
```

We can do it like above, but we can't do dynamic filtering by using that approach. By using `get_queryset` we can do dynamic filtering, using any data/value/information we have, it means we also can use `name` parameter that is sent by `GET`, and it's available on `kwargs`, or in this case, on `self.kwargs["some_key"]` where `some_key` is any parameter you specified

Django: Search form in Class Based ListView

Solution

Problem

Related problems