Django Class Based View with get_queryset()

Question

I would like to use get_queryset() with Class Based View but I don't overcome to display variables in my template.

The function is very simple :

class MyClassView(LoginRequiredMixin, ListView) :

    template_name = 'my_template.html'
    model = Foo

    def get_queryset(self) :

        foo = Foo.objects.order_by('-id')
        bar = foo.filter(Country=64)
        return foo, bar

And my template :

<table style="width:120%">
                <tbody>
                <tr>
                    <th>ID</th>
                </tr>
                {% for item in foo %}
                <tr>
                    <td>{{ foo.id }}</td>
                </tr>
                {% endfor %}
                </tbody>
            </table>
<br></br>
<table style="width:120%">
                <tbody>
                <tr>
                    <th>ID</th>
                </tr>
                {% for item in bar %}
                <tr>
                    <td>{{ bar.id }}</td>
                </tr>
                {% endfor %}
                </tbody>
            </table>

I have to use Context dictionary ?

Alasdair · Accepted Answer · 2017-10-20 09:38:07Z

16

The get_queryset method for a ListView should return a single queryset (or list of items). If you want to add another variable to the context, then override get_context_data as well:

class MyClassView(LoginRequiredMixin, ListView) :

    template_name = 'my_template.html'
    model = Foo

    def get_queryset(self) :
        queryset = Foo.objects.order_by('-id')
        return queryset

    def get_context_data(self, **kwargs):
        context = super(MyClassView, self).get_context_data(**kwargs)
        context['bar_list'] = context['foo_list'].filter(Country=64)
        return context

In the template for a ListView, you access the queryset with object_list or <model>_list (e.g. foo_list), unless you set context_object_name. I've used bar_list in get_context_data to be consistent with that. You need to change the template to loop through {% for item in foo_list %} and {% for item in bar_list %}

edited Oct 20, 2017 at 9:38

answered Oct 20, 2017 at 9:35

Alasdair

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6 Comments

user8060120 Over a year ago

by OP logic may be context['bars'] = self.get_queryset().filter(Country=64)?

Essex Over a year ago

Thank you for your answer. But I don't overcome to display foo in my template and I don't understand why ?

Alasdair Over a year ago

You're probably using the wrong variable in your template then. It's harder to help when you've used made up variable names like foo and bar in your view and template.

Alasdair Over a year ago

@BearBrown I've removed the repeated Foo.objects, but fetched the queryset from the context instead of calling get_queryset again.

Essex Over a year ago

I'm just getting an issue :

Exception Type: KeyError at /Foo/List/ Exception Value: 'foo_list' in context['bar_list'] = context['foo_list'].filter(Country=64)

|

Benjamin Hicks · Accepted Answer · 2017-10-20 09:48:04Z

1

Two things:

1) get_queryset returns, well, a QuerySet. You're returning a tuple. 2) Listview by default passes the query set into a template variable called object_list

However, you can do this all in the template with zero overrides to methods.

{% for item in object_list %}
    {% if item.country == 64 %}
    <tr>
      <td>{{ item.id }}</td>
    </tr>
   {% endif %}
{% endfor %}

That would iterate over all items Foo and only print ones that have country == 64 (If that's a foreign key, you'd need to construct the query differently.)

If for some reason you must do this in the view, you'll need to tweak by get_queryset and get_context to have two different object lists.

answered Oct 20, 2017 at 9:48

Benjamin Hicks

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