Site Layout and Structure ¶

There is an example App Engine site within the Tipfy package contained in the in the project/app/ directory (src).

For this example, we'll copy this directory to a new demo App named fooapp.appspot.com.

cp -R app/ fooapp.appspot.com

Default Site Structure¶

The "site" structure is basic and has the following featured elements.

• fooapp.appspot.com/
  • app.yaml - the app engine site configuration file (src)
  • main.py - Entry point of application (src)
  • config.py - covered in the next section configuration (src)
  • urls.py - TODO - covered in guide/routing (src)
  • apps/ - this is where all your apps go (ie apps within your application, think modules), such as wiki, pastebin, etc.
    • hello_world/ - and example app/module (more below)
      • urls.py - the routes for this app/module (src).
      • handlers.py - the Request handlers for this app/module (src)
  • lib/ - TODO - where should the tipfy lib go?
  • locale/ - where translations are stored.
  • static/ - location of staticly served appengine files.
    • favicon.ico and robots.txt as placeholders
  • templates/ - where the templates go. Jinja2 is the templating engine used by default.
    • hello_world.html - a placeholder jinja2 template for hello_world app/module.

Running the App¶

Before running the fooapp, here's a brief explanation of the "execution path" that occurs..

• Browser requests http://localhost:8080/pretty
• The App Engine fires up the Application with app.yaml configuration.
• main.py is loaded.
  • config.py and config dictionary is loaded
  • WSGI app created and run
• tipfy
  • loads the /urls.py in root which in turn loads apps/*/urls.py included" in /config.py
  • Finds the handler for http://localhost:8080**/pretty
    • Handler is apps.hello_world.handlers.PrettyHelloWorldHandler
• import apps.hello_world.handlers.PrettyHelloWorldHandler class
• class PrettyHelloWorldHandler(RequestHandler) is created
  • def get(self): is called as its a GET request
    • return render_response('hello_world.html', message='Hello, World!')
      • templates/hello_world.html is loaded and parsed.
        • Response object returned
• WSGI app send to browser.
  • Or some error message if caught

• Version: latest
• Edited by Vinay Sajip on 10/23/10 5:44 AM
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