在烧瓶中发布/重定向/获取模式

我的玩具应用程序的查看功能是:

The view function of my toy app was:

@app.route('/', methods=['GET', 'POST'])
def index():
    name = None
    form = NameForm()
    if form.validate_on_submit():
        name = form.name.data
        form.name.data = ''
    return render_template('index.html', form=form, name=name)

当我使用PRG时，它看起来像这样:

And it looks like this when I use PRG:

@app.route('/', methods=['GET', 'POST'])
def index():
    form = NameForm()
    if form.validate_on_submit():
        session['name'] = form.name.data
        return redirect(url_for('index'))
    return render_template('index.html', form=form, name=session.get('name'))

如您所见，form.name.data = ''行用于在第一个版本中清除输入字段，但在第二个版本中则不需要.我以为Flask-WTF会自动将StringField中的文本传递到新的form实例中，但是由于某些原因，它没有.

As you can see, the form.name.data = '' line is used to clear the input field in the first version, but it's not needed in the second version. I thought Flask-WTF would automatically pass the text in StringField into the new form instance, but for some reasons, it didn't.

我的问题是:为什么在使用PRG时，不同请求之间的form.name.data不再可用?

My question is: Why form.name.data is no longer available between different requests when I use PRG?