Screencasts

Groundhog 1: Mapping URLs to Code (35 minutes 49 seconds)

August 3, 2010

In the first screencast in this series, we use BFG to begin building (with apologies to Armin Ronacher) a clone of the open source Flask "microframework" that we name Groundhog. At the end of the first video, we have built enough of Groundhog to allow users to map URLs to code in a way that will be familiar to Flask developers.

Groundhog 2: Generating URLs (24 minutes 56 seconds)

August 4, 2010

In the second screencast in this series, we give Groundhog's users the ability to generate URLs based on routing patterns associated with user-defined view functions. At the end of the second video, a Groundhog user can use the url_for method of the application to generate URLs which point into his application. We also teach Groundhog how to redirect to slash-appended routes and we show off the interactive exception debugger (WebError's EvalException).

Groundhog 3: HTML Templating (39 minutes 38 seconds)

August 5, 2010

In the third screencast in this series, we allow Groundhog users to render HTML using Jinja2 and Chameleon-ZPT templates. We add a render_template method of the Groundhog application object and we provide custom renderer globals.

Groundhog 4: Sessions and Flash Messages (28 minutes 0 seconds)

August 6, 2010

In the fourth Groundhog screencast, we give our microframework's users a way to store information in sessions by making use of Beaker middleware. We then implement flash messaging on top of this sessioning machinery.

Groundhog 5: Exception Handling (38 minutes 33 seconds)

August 10, 2010

In the fifth screencast in the Groundhog series, we equip our microframework with a way to translate exceptions raised by developers into HTTP responses. We then allow our developers to use convenience APIs named abort and redirect to raise exceptions. Finally, we allow them to customize the appearance of exceptions they raise.

Groundhog 6: Events and Context Locals (38 minutes 45 seconds)

August 11, 2010

In the sixth and final screencast in the Groundhog series, we allow our microframework's users to subscribe to and receive events, which are objects broadcast by BFG at various well-known points during its processing cycle. We also allow our users to define and send their own custom event types. Once we've built up some event machinery, we use it to implement "importable locals" (aka "stacked object proxies" or "context locals").

An Introduction to Deform (uses Pylons) (36 minutes 37 seconds)

September 3, 2010

We introduce the Deform form generation library by building an application using the Pylons web framework. Deform is a framework-independent form generation library written by the authors of BFG (and other Repoze projects). In the screencast, we build a small application using Deform in "real time".