[FIXED] How to validate form field in django?

Issue

I want to make shure that the current value of the bid field is not less than current biggest bid. This is my form with a custom clean method.

Form:

class Place_A_Bid_Form(forms.Form):
    listing = forms.CharField(widget=forms.TextInput(attrs={"type":"hidden"}))
    bid = forms.IntegerField(widget=forms.NumberInput(attrs={"class":"form-control"}), min_value=1)

    def clean_bid(self, biggestBid):
        bid = self.cleaned_data["bid"]
        if bid < biggestBid:
            raise ValidationError("""New bid shouldn't be less than starting bid, or 
                                    if any bids have been placed then new bid 
                                    should be greater than current biggest bid""")
        return bid

View:

def place_a_bid(request):
    if request.method == "POST":
        form = Place_A_Bid_Form(request.POST)
        user = User.objects.get(username=request.user.username)
        biggest_bid = Bid.objects.filter(user=user).aggregate(Max("amount"))
        if form.is_valid():
            data = form.cleaned_data
            user_obj = User.objects.get(username=request.user.username)
            listing_obj = Listing.objects.get(title=data["listing"])
            Bid.objects.update_or_create(
                user=user_obj,
                listing=listing_obj,
                amount=data["bid"]
            )
        return redirect(listing_obj)

In view I am extracting current value that I am going to compare to, and I can't figure out how to pass this value to my form field's clean method. Or maybe I'm doing this wrong? So how to do properly this sort of validation?

Solution

class Place_A_Bid_Form(forms.Form):
    listing = forms.CharField(widget=forms.TextInput(attrs={"type":"hidden"}))
    bid = forms.IntegerField(widget=forms.NumberInput(attrs={"class":"form-control"}),
    min_value=1)

    def __init__(self,biggestBid=0 *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.biggestBid = biggestBid

    def clean_bid(self):
        bid = self.cleaned_data["bid"]
        if bid < self.biggestBid:
            raise ValidationError("""New bid shouldn't be less than starting bid, or 
                                    if any bids have been placed then new bid 
                                    should be greater than current biggest bid""")
        return bid

and then in views.py:

def place_a_bid(request):
    if request.method == "POST":
        dict = Bid.objects.filter(user=user).aggregate(Max("amount"))
        form = Place_A_Bid_Form(biggestBid=dict['amount__max'], data=request.POST)
        user = User.objects.get(username=request.user.username)
        if form.is_valid():
            data = form.cleaned_data
            user_obj = User.objects.get(username=request.user.username)
            listing_obj = Listing.objects.get(title=data["listing"])
            Bid.objects.update_or_create(
                user=user_obj,
                listing=listing_obj,
                amount=data["bid"]
            )
        return redirect(listing_obj)

Answered By - eisa nahardani