将字段动态添加到 WTForms 表单

Question

我想定义一个表单类，其字段基于name: label 的字典。我尝试了以下方法，几乎​​奏效了。但是，在模板中呈现字段会给出AttributeError: 'UnboundField' object has no attribute '__call__'。如何在表单中动态添加字段？

def build_form(name, record):
    class ContactForm(FlaskForm):
        name = StringField(name)
        fieldlist = {}

        for key, value in record.items():
            fieldlist[key] = StringField(key)

    @app.route('/', methods=['GET', 'POST'])
    def showform():
        form = ContactForm(request.form)

        if request.method == 'POST':
            return 'form processed'

        return render_template('cardcompare.tpl', record=record, form=form)

<form method=post>
    {{ form.name() }}
    {% for key, value in record.items() %}
        {{ form.fieldlist[key]() }}
    {% endfor %}
    <input type=submit value=Register>
</form>

Answer 1

使用setattr 添加新字段作为表单类的属性。这将导致 WTForms 正确设置字段，而不是保留未绑定的字段。

# form class with static fields
class MyForm(FlaskForm):
    name = StringField('static field')

record = {'field1': 'label1', 'field2': 'label2'}

# add dynamic fields
for key, value in record.items():
    setattr(MyForm, key, StringField(value))

在模板中，您可以使用 attr 过滤器遍历字段。

{% for key, value in record.items() %}:
    {{ form|attr(key)() }}
{% endfor %}