Change form input from text value to model instance in django - django

Question

I want to create Aviz entry using AJAX form.
In the form the input material has a jquery ui function autocomplete, that gets all the material names from the Material Model.
When I submit the form I get this error in the console : ValueError: Cannot assign "'ADEZIV LIPIRE VATA MINERALA, CT 180, 25 KG CERESIT'": "Aviz.material" must be a "Material" instance.
I know that I need to get the input from the form, and turn it in a Material instance...but do not know how/did not find any info about this.
models.py:
class Material(models.Model):
name = models.CharField(max_length=255,default=None,verbose_name='Nume material')
class Aviz(models.Model):
material = models.ForeignKey(Material, on_delete=models.CASCADE,related_name="aviz")
quantity = models.FloatField(default=0,verbose_name="Cantitate")
views.py:
class AvizCreate(LoginRequiredMixin, AjaxCreateView):
model = Aviz
form_class = AvizForm
def get_form_kwargs(self):
kwargs = super().get_form_kwargs()
kwargs['pk'] = self.kwargs.get('centrudecost')
return kwargs
#login_required
def autocomplete(request):
if 'term' in request.GET:
qs = Material.objects.filter(name__icontains=request.GET.get('term'))
name = list()
id = list()
cod_nexus = list()
name = [prod.name for prod in qs]
id = [prod.pk for prod in qs]
cod_nexus = [prod.cod_nexus for prod in qs]
return JsonResponse({"name": name, "id":id, "cod_nexus":cod_nexus}, safe=False)
templates.html
$('#id_material').autocomplete({
source: function(request, response) {
$.ajax({
url: "{% url 'materiale:autocomplete' %}",
dataType: "json",
data: {
term: request.term
},
success: function(data) {
response($.map(data.name, function(value, key) {
return {
label: data.name[key],
value: data.name[key],
id:data.id[key],
cod_nexus:data.cod_nexus[key]
}
}));
}
});
},
select: async function(event, ui) {
let resp = await fetch("{% url 'materiale:get_um' 1 %}".replace('1',ui.item.id));
let json = await resp.json()
$('#id_um').val(json);
}
})
}
forms.py:
class AvizForm(BootstrapHelperForm, forms.ModelForm):
material = forms.CharField()
um = forms.CharField()
class Meta:
model = Aviz
fields = ('centrudecost','data','aviz', 'material','um','quantity',)
widgets = {
'data': DateInput(),
'centrudecost': forms.HiddenInput(),
# 'material': forms.Select(attrs={'class': 'form-control'})
}
def __init__(self, *args, **kwargs):
pk = kwargs.pop('pk', None)
super(AvizForm, self).__init__(*args, **kwargs)
self.fields['um'].widget.attrs['readonly'] = True
I know that by deleting this material = forms.CharField() from the forms.py, the form works, and a Aviz instance is created referencing the material model, but i need to use the autocomplete function in the form