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diff --git a/app/static/doc/flask-docs/_sources/patterns/wtforms.txt b/app/static/doc/flask-docs/_sources/patterns/wtforms.txt deleted file mode 100644 index 93824df..0000000 --- a/app/static/doc/flask-docs/_sources/patterns/wtforms.txt +++ /dev/null @@ -1,124 +0,0 @@ -Form Validation with WTForms -============================ - -When you have to work with form data submitted by a browser view code -quickly becomes very hard to read. There are libraries out there designed -to make this process easier to manage. One of them is `WTForms`_ which we -will handle here. If you find yourself in the situation of having many -forms, you might want to give it a try. - -When you are working with WTForms you have to define your forms as classes -first. I recommend breaking up the application into multiple modules -(:ref:`larger-applications`) for that and adding a separate module for the -forms. - -.. admonition:: Getting most of WTForms with an Extension - - The `Flask-WTF`_ extension expands on this pattern and adds a few - handful little helpers that make working with forms and Flask more - fun. You can get it from `PyPI - <http://pypi.python.org/pypi/Flask-WTF>`_. - -.. _Flask-WTF: http://packages.python.org/Flask-WTF/ - -The Forms ---------- - -This is an example form for a typical registration page:: - - from wtforms import Form, BooleanField, TextField, validators - - class RegistrationForm(Form): - username = TextField('Username', [validators.Length(min=4, max=25)]) - email = TextField('Email Address', [validators.Length(min=6, max=35)]) - password = PasswordField('New Password', [ - validators.Required(), - validators.EqualTo('confirm', message='Passwords must match') - ]) - confirm = PasswordField('Repeat Password') - accept_tos = BooleanField('I accept the TOS', [validators.Required()]) - -In the View ------------ - -In the view function, the usage of this form looks like this:: - - @app.route('/register', methods=['GET', 'POST']) - def register(): - form = RegistrationForm(request.form) - if request.method == 'POST' and form.validate(): - user = User(form.username.data, form.email.data, - form.password.data) - db_session.add(user) - flash('Thanks for registering') - return redirect(url_for('login')) - return render_template('register.html', form=form) - -Notice that we are implying that the view is using SQLAlchemy here -(:ref:`sqlalchemy-pattern`) but this is no requirement of course. Adapt -the code as necessary. - -Things to remember: - -1. create the form from the request :attr:`~flask.request.form` value if - the data is submitted via the HTTP `POST` method and - :attr:`~flask.request.args` if the data is submitted as `GET`. -2. to validate the data, call the :func:`~wtforms.form.Form.validate` - method which will return `True` if the data validates, `False` - otherwise. -3. to access individual values from the form, access `form.<NAME>.data`. - -Forms in Templates ------------------- - -Now to the template side. When you pass the form to the templates you can -easily render them there. Look at the following example template to see -how easy this is. WTForms does half the form generation for us already. -To make it even nicer, we can write a macro that renders a field with -label and a list of errors if there are any. - -Here's an example `_formhelpers.html` template with such a macro: - -.. sourcecode:: html+jinja - - {% macro render_field(field) %} - <dt>{{ field.label }} - <dd>{{ field(**kwargs)|safe }} - {% if field.errors %} - <ul class="errors"> - {% for error in field.errors %}<li>{{ error }}{% endfor %} - </ul> - {% endif %} - </dd> - {% endmacro %} - -This macro accepts a couple of keyword arguments that are forwarded to -WTForm's field function that renders the field for us. The keyword -arguments will be inserted as HTML attributes. So for example you can -call ``render_field(form.username, class='username')`` to add a class to -the input element. Note that WTForms returns standard Python unicode -strings, so we have to tell Jinja2 that this data is already HTML escaped -with the `|safe` filter. - -Here the `register.html` template for the function we used above which -takes advantage of the `_formhelpers.html` template: - -.. sourcecode:: html+jinja - - {% from "_formhelpers.html" import render_field %} - <form method="post" action="/register"> - <dl> - {{ render_field(form.username) }} - {{ render_field(form.email) }} - {{ render_field(form.password) }} - {{ render_field(form.confirm) }} - {{ render_field(form.accept_tos) }} - </dl> - <p><input type=submit value=Register> - </form> - -For more information about WTForms, head over to the `WTForms -website`_. - -.. _WTForms: http://wtforms.simplecodes.com/ -.. _WTForms website: http://wtforms.simplecodes.com/ |