Wille Apps

Wille Apps are special web applications that run on Wille Server, and can access services via a Wille Client. In this section, we will briefly go through what is needed in order to create a new Wille App.

Wille Apps are written in Python using Wille’s light-weight web application framework. Various third-party Python libraries (such as template engines) can be used together with Apps for easiest application development.

Creating an App

First, make sure your working directory is set to your apps folder:

cd myproject/apps

The easiest way to start creating a new Wille App is to use wille-admin script:

wille-admin.py createapp myapp

For your convenience, the following files are created to the skeleton:

• myapp.py - Your application code file
• willeapp.properties - Description of your application for Wille

The following application code is created for you as an app skeleton:

class IndexPage:
        def GET(self, request):
                # (Insert your code here)
                return "Result view"

urls = ( ("/", IndexPage),)

Once your app files have been created, you can already try it out in a Wille Server.

Writing Apps

In order to test and try out Apps, Wille Server is required. Note that when developing new Apps, it is generally good idea to enable reloader:

wille-server.py -r

When enabled, Wille Server will automatically detect and reload changed Python source code files, requiring fewer server restarts during application development. Reloader works best when combined with debug mode:

wille-server.py -dr

Note: reloader doesn’t work with Jython.

Accessing Input Parameters

Input parameters (both GET and POST) can be accessed with request.input().

For example:

var1 = request.input('var1')`

In order to retrieve all parameters at once, simply call:

vars = request.input()

Accessing Wille Client

An instance of Wille Client can be retrieved with request.wille_client().

For instance:

client = request.wille_client()

With Wille client, services and keyring can be accessed. For more information, see the section on Wille Client.

URL Mappings

Multiple URLs maybe added to urls variable. Regular expressions (^re^) can be used to match multiple URLs. In order to capture these expressions as request variables, provide them with parenthesis ().

Processing POST Data

If you wish to process input data sent via POST, make sure you encode them as multipart/form-data when sending your form.

In HTML form this requires you to add enctype header to form element:

<form enctype="multipart/form-data" method="post" />
        ...
</form>

Returning with a Response

When returning from request handler methods (GET, POST) your return value determines how the response from your application is generated.

A simple text response is generated by returning a text value (str, unicode):

return "Response"

By adding a second argument, you can add metadata fields to your response:

return ("Response", {'Content-type': 'application/xml; charset=utf-8'})

Using profiles with Apps

Similar to Wille Services, Apps can be also organised into groups by using profiles.

Profiles are specified per-app, by adding profile property into each App’s willeapp.properties file:

profile=profile1,profile2

Profile names are common between services and apps, and can be therefore used to group together various services and apps.