Creating custom wtforms.widgets in a Flask.app. Custom Form, Custom Field and Custom Widget.

flask_wtforms_custom_widget.py

from flask import Flask
from wtforms import Form, Field, TextField
from wtforms.widgets import TextInput, html_params

# http://wtforms.simplecodes.com/docs/0.6/widgets.html#custom-widgets
def render_ul_users(field, ul_class='awesome_class', **kwargs):
    kwargs.setdefault('id', field.id)
    if hasattr(field, 'users'):
        html = [u'<ul %s>' % html_params(id=field.id, class_=ul_class)]
        # A sure hope users is iterable:
        for u in field.users:
            params = dict(kwargs,id=u['_id'])
            html.append(u'<li %s>%s</li>' % (html_params(**params),u['name']))
        html.append('<li>Muhahahaha <--- This is hard-code</li>')
        html.append(u'</ul>')
    else:
        html = '<h1>Too bad, so sad</h1>'
    return u''.join(html)

class CoxinhaWidget(object):
    _js = """alert('{} says: Torresmo eh mto da hora.');"""
    html_params = staticmethod(html_params)

    def __init__(self, input_type='submit', text=''):
        self.input_type = input_type
        self.text = text

    def __call__(self, field, **kwargs):
        kwargs.setdefault('id', field.id)
        if hasattr(field, 'users'):
            html = [u'<ul %s>' % html_params(id=field.id)]
            # A sure hope users is iterable:
            for u in field.users:
                params = dict(kwargs,id=u['_id'],onclick=self._js.format(u['name']))
                html.append(u'<li %s>%s</li>' % (html_params(**params),u['name']))
            html.append('<li>TUKA EH + TORRESMO</li>')
            html.append(u'</ul>')
        else:
            html = '<h1>Too bad, so sad</h1>'
        return u''.join(html)

class CoxinhaField(Field):
  widget = CoxinhaWidget()
  def __init__(self, label=None, validators=None, text='Save', **kwargs):
    super(CoxinhaField, self).__init__(label, validators, **kwargs)

class SomeRandomForm(Form):
    name = TextField('Name')
    h4x0r_field = Field(widget=render_ul_users)
    neat_field = CoxinhaField()

    def __init__(self, users, *args, **kwargs):
        super(SomeRandomForm, self).__init__(*args,**kwargs)
        self.h4x0r_field.users = users
        self.neat_field.users = users


app = Flask(__name__, static_url_path='')

import itertools
from random import randint
def _gen_users(s):
    return [ dict(_id=randint(1,101111), name=n) for n in list(map("".join, itertools.permutations(s)))[0:10] ]

@app.route('/')
def index():
    users = _gen_users('tutuca')
    form = SomeRandomForm(users)
    print form.h4x0r_field
    print form.neat_field
    return form.neat_field()

@app.route('/h4x')
def h4x():
    users = _gen_users('tuanny')
    form = SomeRandomForm(users)
    return form.h4x0r_field()

@app.route('/neat')
def neat():
    users = _gen_users('hipopotuka')
    form = SomeRandomForm(users)
    return form.neat_field()


if __name__ == '__main__':
    app.run(debug=True)