Flask wtforms - 'UnboundField' 对象不可调用，动态字段无法正确初始化

Question

app.py

from flask import Flask, render_template
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, FieldList, FormField

app = Flask(__name__)
app.config['SECRET_KEY'] = 'apple pie'


class BookForm(FlaskForm):
    book = StringField('book title')


class LibraryForm(FlaskForm):
    def __init__(self, min_entries=0, *args, **kwargs):
        super(LibraryForm, self).__init__(*args, **kwargs)
        self.books = FieldList(FormField(BookForm), min_entries=min_entries)

    library = StringField('Library name')
    books = FieldList(FormField(BookForm), min_entries=3)
    submit = SubmitField('Submit')


@app.route('/book', methods=['GET', 'POST'])
def book():
    form = LibraryForm(min_entries=5)
    if form.validate_on_submit():
        return 'aww yeah'
    return render_template('books.html', form=form)

books.html

<html>
<form method="POST" action="">
    {{ form.hidden_tag() }}
    <div>{{ form.library.label }}: {{ form.library() }}</div>
    <div>{{ form.books.label }}: {{ form.books() }}</div>
    <div>{{ form.submit.label }}: {{ form.submit() }}</div>
</html>

我的目标是让我的表单初始化时包含灵活数量的条目，例如 link 中所示的示例。每当我运行我的代码时，我都会收到以下错误：

TypeError: 'UnboundField' object is not callable

当我注释掉 init 函数时，表单按预期工作，除了不灵活的 Book Fields 数量。我花了很多时间寻找答案，但找不到任何解决问题的方法。

example of how it should look

感谢任何帮助！

Answer 1

这不是理想的解决方案，但它确实有效。

from flask import Flask, render_template
from flask_wtf import FlaskForm, Form
from wtforms import StringField, SubmitField, FieldList, FormField

app = Flask(__name__)
app.config['SECRET_KEY'] = 'apple pie'


class BookForm(FlaskForm):
    book = StringField('book title')


class LibraryForm(FlaskForm):
    library = StringField('Library name')
    books = FieldList(FormField(BookForm))
    submit = SubmitField('Submit')


@app.route('/book', methods=['GET', 'POST'])
def book():
    form = LibraryForm()
    if form.validate_on_submit():
        return 'aww yeah'
    for i in range(6):
        form.books.append_entry()

    return render_template('books.html', form = form)

Flask wtforms - 'UnboundField' 对象不可调用，动态字段无法正确初始化

Flask wtforms - 'UnboundField' object is not callable, dynamic field won't init properly

flask

wtforms

flask-wtforms