python - Django:如何根据选择的其他表单字段选项更改具有不同查询集的表单字段选择选项？

Question

当用户使用 jquery 在“BuySell”下拉选项中选择“Sell”时，我希望我的硬币字段的查询集发生变化。更改下拉列表后，我使用 AJAX 发送获取请求，在我的 View 中选择该请求，然后重新加载表单，这是我在 TransactionForm 的 init 方法中覆盖默认硬币字段查询集的地方。

这没有按预期工作，硬币下拉选项没有发生任何变化，我也没有收到任何错误(包括在检查元素时在“网络”选项卡中出现的错误)。

我想知道这是否与我在这里调用表单的方式有关:

form = TransactionForm(user = request.user, coin_price = GetCoin("Bitcoin").price)

和表单初始化方法:

def __init__(self, coin_price = None, user = None, *args, **kwargs):    
        super(TransactionForm, self).__init__(*args, **kwargs)

        if user:

            self.user = user
            qs_coin = Portfolio.objects.filter(user = self.user).values('coin').distinct()
            print("qs_coin test: {}".format(qs_coin))
            self.fields['coin'].queryset = qs_coin

完整代码:

表格

class TransactionForm(forms.ModelForm):     
    CHOICES = (('Buy', 'Buy'), ('Sell', 'Sell'),)

    coin = forms.ModelChoiceField(queryset = Coin.objects.all()) 
    buysell = forms.ChoiceField(choices = CHOICES)

    field_order = ['buysell', 'coin', 'amount', 'trade_price']

    class Meta:
        model = Transaction
        fields = {'buysell', 'coin', 'amount', 'trade_price'}

    def __init__(self, coin_price = None, user = None, *args, **kwargs):
        super(TransactionForm, self).__init__(*args, **kwargs)
        print("Transaction form init: ", user, coin_price)

        if user:
            self.user = user
            qs_coin = Portfolio.objects.filter(user = self.user).values('coin').distinct()
            print("qs_coin test: {}".format(qs_coin))
            self.fields['coin'].queryset = qs_coin

View 片段

def add_transaction(request):

    if request.method == "GET":
        if request.is_ajax():
            print("ajax test")

            #print(request.GET.get)
            print(request.GET.get('coin'))
            print(request.GET.get('buysell'))

            view_coin = None 
            if request.GET.get('coin'):
                view_coin = GetCoin(request.GET.get('coin')).price

            data = {
                'view_buysell': request.GET.get('buysell'),
                'view_coin': request.GET.get('coin'),
                'view_amount': "test",
                'view_price': view_coin
            }

            form = TransactionForm(user = request.user, coin_price = GetCoin("Bitcoin").price)

            return JsonResponse(data)

j查询

$('#id_buysell').on('change', function(){

        console.log("buysell");

        var $id_buysell = $('#id_buysell').val();
        console.log($id_buysell);

        $.ajax({
            method: "GET",
            url: "/myportfolio/add_transaction",
            dataType: 'json',
            data: { buysell: $id_buysell },
            success: function(data, status) {
                console.log("SUCCESS:");
                console.log(data);
                console.log(data['view_buysell']);

            },
            error: function(response) {

            }
        });

    });

$('#id_coin').on('change', function(){

    console.log("test")
    console.log("coin change")

    var $id_coin = $('#id_coin').find("option:selected").text();
    console.log($id_coin);

    $.ajax({
        method: "GET",
        url: "/myportfolio/add_transaction",
        dataType: 'json',
        data: {coin: $id_coin},
        success: function(data, status) {
            console.log("SUCCESS:");
            console.log(data);
            console.log(data['view_buysell']);

            $("#id_trade_price").val(data['view_price']);
        },
        error: function(response) {

        }
    });

Answer 1

我试图做的是不必要的。

实现此目的的正确方法是将我所有的查询集转换为列表，然后将它们传递给 JsonResponse 中的 jquery。然后我可以在需要时清除这些列表并将其作为我的 jquery 中的选择选项加载。

更新代码:

观看次数

if request.method == "GET":
        if request.is_ajax():
            print("ajax test")

            #print(request.GET.get)
            print(request.GET.get('coin'))
            print(request.GET.get('buysell'))

            view_coin = None 
            if request.GET.get('coin'):
                view_coin = GetCoin(request.GET.get('coin')).price

            coin_sell_options = Portfolio.objects.filter(user = request.user).values('coin').distinct()
            coin_buy_options = Coin.objects.all()

            coin_buy_options = [x.coin for x in coin_buy_options]

            coins = [key['coin'] for key in coin_sell_options]
            coin_amount = list(Portfolio.objects.filter(user = request.user, coin__in = coins).values_list('amount', flat = True))
            coin_amount = [str(x) for x in coin_amount]
            print(coin_amount)

            data = {
                'view_buysell': request.GET.get('buysell'),
                'view_coin': request.GET.get('coin'),
                'view_amount': "test",
                'view_price': view_coin,
                'coin_sell_options': list(coin_sell_options),
                'coin_buy_options': list(coin_buy_options),
                'coin_amounts': coin_amount
            }

            form = TransactionForm(user = request.user, coin_price = GetCoin("Bitcoin").price)

            return JsonResponse(data)

j查询

$('#id_buysell').on('change', function(){

            console.log("buysell");

            var $id_buysell = $('#id_buysell').val();
            console.log($id_buysell);

            $.ajax({
                method: "GET",
                url: "/myportfolio/add_transaction",
                dataType: 'json',
                data: { buysell: $id_buysell },
                success: function(data, status) {
                    console.log("SUCCESS:");
                    console.log(data);
                    console.log(data['view_buysell']);

                    $("#id_coin").empty();                  

                    var items = data['coin_options'];

                    console.log(items);

                    $.each(items, function(key, value) {
                        console.log(value.coin);
                        $("#id_coin").append(new Option(value.coin));
                    });


                },
                error: function(response) {

                }
            });

        });