Create a filterset with arrayfield

[Michele Gatti]

Hi i have a problem,i use postgreSQL and django.

I have a field in model with arrayField i can't underestand in which way is possible create a filter contain on that field.

Thanks

[Carlton Gibson]

You can query by hand right? See https://docs.djangoproject.com/en/1.11/ref/contrib/postgres/fields/#querying-arrayfield

So first option is (always) to specify a custom `method` — you can use any logic you like there. 

But have you tried specifying `lookup_expr` https://django-filter.readthedocs.io/en/develop/ref/filters.html#lookup-expr — the contrib fields should make that Just Work™. 

If you run into specific issues it'll be easier to say something concrete. 

[Michele Gatti]

i create this filter class 

class PhotoFilter(filters.FilterSet):

    class Meta:
        model = Photo
        fields = {'brand__id':['exact'],
                  'mention_language':['exact'],
                  'user__sex':['exact'],
                  'mv_comments_count':['gte'],
                  'mv_likes_count':['gte'],
                  'mention_tags':['contains']}

When i run the project i recived thi error 

AssertionError: PhotoFilter resolved field 'mention_tags' with 'contains' lookup to an unrecognized field type ArrayField. Try adding an override to 'Meta.filter_overrides'. See: https://django-filter.readthedocs.io/en/develop/ref/filterset.html#customise-filter-generation-with-filter-overrides

but in django-filter there isn't a ArrayFilter to overrides 

[Carlton Gibson]

I think you'd want a CharFilter. Try adding an override for that for ArrayField.

Or better, declare filters explicitly.

Either should work.

📱

[Michele Gatti]

I try this code:

filter_overrides = {
    ArrayField: {
        'filter_class': filters.CharFilter,
        'extra': lambda f: {
            'lookup_expr': 'icontains',
        },
    },
}

and work with one word if i want more than one how can do it?

[Carlton Gibson]

Hi Michele, 

First I'd stop using the dict fields syntax and explicitly declare fields. 

If you're looking to filter for a list of values you can use the CSV filtering...

class CharInFilter(django_filters.BaseInFilter, django_filters.CharFilter):
    pass

class PhotoFilter(django_filters.FilterSet):
    mention_tags = CharInFilter(lookup_expr='icontains')

... or such.

See: https://django-filter.readthedocs.io/en/develop/ref/filters.html#baseinfilter

C.

[Michele Gatti]

Thanks i resolved