This document describes how to implement Modules. A Module allows packages and services to be created. They define the fields requested when adding or editing packages and services, as well as handle all communication with remote servers to provision said packages and services.
Use the Extension Generator
As of Blesta 4.12 we've included a useful tool to help developers get started and save time. Blesta's Extension Generator can be used to generate many the files necessary for a module and will create basic code with an option to include comments to help you understand each part of the code.
Getting Started with Modules
For the purpose of this manual, the module name we'll refer to is my_module. Your module name will, of course, differ.
Module names must be unique
A user will not be able to install two module with the same name.
Modules are fully contained within their named module directory and placed in the /installpath/components/modules/ directory. Each module is only required to contain a single class, representing the module, but the following is the recommended structure:
If your module requires any code to execute when installed, place that logic in your module's install() method.
If your module required code to install, it likely requires code to uninstall. Place that logic in your module's uninstall() method.
There are two parameters passed to the uninstall() method. The first ($module_id) is the ID of the module being uninstalled. Because a module can be installed independently under different companies you may need to perform uninstall logic for a single module instance. The second parameter ($last_instance) identifies whether or not this is the last instance of this module in the system. If true, be sure to remove any remaining remnants of the module.
When the version of your code differs from that recorded within Blesta a user may initiate an upgrade, which will invoke your module's upgrade() method.
The $current_version is the version currently installed. That is, the version that will be upgraded from.
Blesta facilitates error message passing through the use of the Input component. Simply load the Input component into your module and set any errors you encounter using Input::setErrors(). The setErrors() method accepts an array of errors. This can be a multi-dimensional array (in the case of multiple errors triggered for the same input or criteria) or a single dimensional array. The first dimension should be the name of the input that triggered the error. The second dimension, if necessary, is used to identify the type of error encountered.
Now that we've looked at some of the basic of creating a module, let's take a look at all of the required methods each module must implement: Module Methods.