I want to add such filters to my internet shop:
Color:
# red
# blue
# green
Material:
# plastic
# wood
# metal
where each of points is a checkbox, color and material are fields of some Django model.
For example if i'm looking for red or blue toys with plastic material, i'll find it in such way:
filtered = SomeModel.objects.filter(material=plastic, color=red, color=blue)
But how to filter it dynamically?(if i have many filters)
# Import
from django.db.models import Q
filter_query = Q()
# Get colors to be filtered
filter_color_list = ['red', 'blue']
# Add Filter by colors
filter_query.add(Q(color__in=filter_color_list), Q.AND)
# Get materials to be filtered
filter_material_list = ['plastic']
# Add filter by material
filter_query.add(Q(material__in=filter_material_list), Q.AND)
# Get filtered objects
filtered = SomeModel.objects.filter(filter_query)
You can add as many filters you want in filter_query, and if none of the filters added it will return all objects of the model.
You can do like
query = SomeModel.objects.filter(material='plastic')
if any_bool_condition:
query = query.filter(color='red')
and you can keep adding filter on query.
For OR condition, you should look https://stackoverflow.com/a/6567918/3864717
Build your tuple with the colours you want, then use that in the query with __in.
Also, I've put strings in here, but if you're not already doing it, I'd suggest using an enum for things like this (unless the colours are user defined somehow maybe).
# this would be set from incoming checkbox values, and may be empty:
colours_to_filter = ('red', 'blue', 'green')
materials_to_filter = ()
query = SomeModel.objects.all()
if colours_to_filter:
query = query.filter(colour__in=colours_to_filter)
if materials_to_filter:
query = query.filter(material__in=materials_to_filter)
I usually do these filterings by using query parameters.
It's based on what users checks for filtering whether it's multiple values or None values.
qs = SomeModel.objects.all()
material = request.GET.get("material")
color = request.GET.get("color")
if material:
qs = qs.fitler(material__in=material)
if color:
qs = qs.fitler(color__in=color)
Notice that there is a package called django-filter. you can use this package for your filterings and it's pretty useful.
And your form would be like this: (EXAMPLE)
<form action="{% url 'view_url' %}" method="GET">
<input type="checkbox" name="color" value="RED">
<input type="checkbox" name="color" value="GREEN">
<input type="checkbox" name="color" value="BLUE">
<button type="submit" value="Submit">Submit</button>
</form>
