Survey application with TurboGears and CatWalk

This tutorial will show you how to implement a simple application for creating and managing online surveys using the Web MegaFramework TurboGears and the model browser CatWalk.

I expect that you already have downloaded TurboGears and have completed the 20 minutes wiki tutorial.

This tutorial will go trough the following steps:

1. Page one
   • Creating and configuring a new TurboGears project
   • Implementing your model
   • Installing CatWalk
   • Security
2. Page two
   • Using CatWalk to create a survey
3. Page tree
   • Rendering a survey list
   • Rendering a single survey
4. Page four
   • Collecting answers
   • Using CatWalk to review your answers
   • Wrap-up and download the survey project

Quite some stuff, so let's get started!

Part one

Creating a new project and configuring your database

Create a new project using tg-admin quickstart, and call it survey $>tg-admin quickstart

Create a database for your project, and configure your dev.cfg and prod.cfg to match your database settings. I'm using postgres and thinks look like this for me: [global] # DATABASE # pick the form for your database sqlobject.dburi="postgres://postgres@localhost/survey"

Implementing your model

Open your model file (model.py) and start defining your model classes.
First our Survey class: class Survey(SQLObject): name = StringCol(length=200) description = StringCol() publish = BoolCol() questions = MultipleJoin('Question') answers = MultipleJoin('Answer')

A Survey have a name and description, it can be publish or not, it might have multiple questions and multiple answers.

Lets add our question object: class Question(SQLObject): text = StringCol() survey = ForeignKey('Survey') options = MultipleJoin('Option') qType = EnumCol(enumValues=['text', 'textarea', 'radio', 'select', 'checkbox'])

Questions have some text, a reference to the survey they belong to, eventually some options and they can be one of 5 possible question types.

Our Option object looks like this: class Option(SQLObject): class sqlmeta: table = 'options_table' text = StringCol() question = ForeignKey('Question')

Option seams to be a protected keyword, that's why I specified another name for it. The class contains a text string and a reference to a question

To collect submitted values we need two classes, Answer and AnswerValue.

Be aware that by using DateTime.now as the default for my DateTimeCol I'm adding a dependency to mx.DateTime, so remember to add from mx import DateTime to your model.

class Answer(SQLObject): answered = DateTimeCol(default=DateTime.now) survey = ForeignKey('Survey') values = MultipleJoin('AnswerValue') class AnswerValue(SQLObject): value = StringCol() answer = ForeignKey('Answer') question = ForeignKey('Question')

I have some problems (at least with postgres) when running tg-admin sql create, due to the order in which tg-admin tries to create the tables. To circumvent it I added the create statements at the bottom of my model file.

Survey.createTable(ifNotExists=True) Question.createTable(ifNotExists=True) Option.createTable(ifNotExists=True) Answer.createTable(ifNotExists=True) AnswerValue.createTable(ifNotExists=True)

You don't need to run tg-admin sql create now, because the tables will be created for you the first time you run the application

You can download a sample model file here

Installing CatWalk

Download the latest version of CatWalk from http://www.checkandshare.com/catwalk/download.html . Save it in the same directory where your model.py file is.
Open your controller.py file and 'mount' CatWalk like this: import turbogears from turbogears import controllers class Root(controllers.Root): from catwalk import CatWalk catwalk=CatWalk() @turbogears.expose(html="survey.templates.welcome") def index(self): import time return dict(now=time.ctime())

Start your engines: $>python survey-start.py

Congratulations, CatWalk should be up an running on http://localhost:8080/catwalk

Security

One word about security. By using CatWalk you are providing an online tool with a great deal of access to your models and valuable data.

By default only localhost (127.0.01) has access to CatWalk. If you want access from another location, add your host name to the allowedHosts list when you mount CatWalk, like this: ... class Root(controllers.Root): from catwalk import CatWalk catwalk=CatWalk(allowedHosts=['127.0.0.1','192.168.2.146']) ...

Chances are that a lot of people share your host name, providing access to other hosts can compromite your data!!!

You can obscure your installation somehow by using another name for catwalk when mounting it. Like this: class Root(controllers.Root): from catwalk import CatWalk yakawakapugaPow =CatWalk( allowedHosts=['127.0.0.1', '192.168.2.146'] ) CatWalk will now gladly run under http://localhost:8080/yakawakapugaPow