Drupal 7 Module Development

Creating Your First Module
We are going to divide this task of building a new module into the three parts:
• Create a new module folder and module files
• Work with the Block Subsystem
• Write automated tests using the SimpleTest framework included in Drupal
We are going to proceed in that order for the sake of simplicity. One might object
that, following agile development processes, we ought to begin by writing our
tests. This approach is called Test-driven Development (TDD), and is a justly
popular methodology.
Agile software development is a particular methodology designed to
help teams of developers effectively and efficiently build software. While
Drupal itself has not been developed using an agile process, it does
facilitate many of the agile practices. To learn more about agile, visit
http://agilemanifesto.org/.
However, our goal here is not to exemplify a particular methodology, but to discover
how to write modules. It is easier to learn module development by first writing the
module, and then learn how to write unit tests. It is easier for two reasons:
• SimpleTest (in spite of its name) is the least simple part of this chapter. It will
have double the code-weight of our actual module.
• We will need to become acquainted with the APIs we are going to use in
development before we attempt to write tests that assume knowledge of
those APIs.
In regular module development, though, you may certainly choose to follow the
TDD approach of writing tests first, and then writing the module.
Let's now move on to the first step of creating a new module.
Creating a new module
Creating Drupal modules is easy. How easy? Easy enough that over 5,000 modules
have been developed, and many Drupal developers are even PHP novices! In fact,
the code in this chapter is an illustration of how easy module coding can be. We are
going to create our first module with only one directory and two small files.
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