Application Context

In order for our application to be functional we define and intialise our Application Context. This allows us to define specific behaviour or charatersitics for each individual application based on our Context definition.

This is one of the most powerfull features of Websaw and as such we will be using it comprehensively as we build our apps.

What is meant by context?

Context is the central hub which is in charge of fixture maintenance (initialization/teardown/cleanup) as well as maintinaing communication between actions and fixtures. In addition the comtext layer maintains communication between individual fixtures themselves.

The main things to understand about context are as follows:

  • There are two builtin base classes of context namely DefaultContxt and BaseContext

    • ctxd (design context) is how we refer to our context at module level and generally override DefaultContext

    • cctx() (current context) returns the context (ctx) from any context class

    • ctx is always the first paramater in any action’s function

There is obviously a lot more to conetxt than the abouve and indeed it performs a lot of the uner-the-hood fucntionality that we need not concern ourselves with.

We will see in later sections just how much of an important role the context layer plays in our applications.

Extending Context with our fixture

So lets extend the DefaultContext by including our custom auth fixture as follows:

# apps/xauth/controllers.py

# extend default context with our fixture
class Context(DefaultContext):
    auth = auth

ctxd = Context()

Thats it! Done. We have extended our context with our custom auth fixture.

In later sections and in particular when we start looking at mixins we will expand upon this.

For now we have our auth fixture in our Context and we are ready to move on.

Important

At this stage we have ALL default fixtures as per the DefaultContext AS WELL AS our custom fixture available to our appliation.

A quick recap

So far we have :

  • defined and intialised our fixture

  • extended and intialised our context

The only thing left to do now is to intialise, mount and of course develop any applciation functionlaity that we need.

In order to do this we should look at our Application layer next where all of this takes place.

So lets get to it.