from flask import Flask, render_template
from flask.ext.wtf import Form, SubmitField, Field, TextInput

app = Flask(__name__)
app.config['SECRET_KEY'] = 'Shh!'


class CustomField(Field):
    widget = TextInput()
    
    def _value(self):
        if self.data:
            return u', '.join(self.data)
        else:
            return u''

    def process_formdata(self, valuelist):
        if valuelist:
            self.data = [x.strip() for x in valuelist[0].split(',')]
        else:
            self.data = []


class ExampleForm(Form):
    status = CustomField()
    submit = SubmitField('POST')