Custom Post Processors
======================

You can implement custom post processors to accomplish your tasks. Each post processor must extend the class **PHPModelGenerator\\SchemaProcessor\\PostProcessor\\PostProcessor**. If you have implemented a post processor add the post processor to your `ModelGenerator` and the post processor will be executed for each class.

A custom post processor which adds a custom trait to the generated model (eg. a trait adding methods for an active record pattern implementation) may look like:

.. code-block:: php

    namespace MyApp\Model\Generator\PostProcessor;

    use MyApp\Model\ActiveRecordTrait;
    use PHPModelGenerator\SchemaProcessor\PostProcessor\PostProcessor;

    class ActiveRecordPostProcessor extends PostProcessor
    {
        public function process(Schema $schema, GeneratorConfiguration $generatorConfiguration): void
        {
            $schema->addTrait(ActiveRecordTrait::class);
        }
    }

.. hint::

    For examples how to implement a custom post processor have a look at the built in post processors located at **src/SchemaProcessor/PostProcessor/**

What can you do inside your custom post processor?

* Add additional traits and interfaces to your models
* Add additional methods and properties to your models
* Hook via **SchemaHooks** into the generated source code and add your snippets at defined places inside the model:

    * Implement the **ConstructorBeforeValidationHookInterface** to add code to the beginning of your constructor
    * Implement the **ConstructorAfterValidationHookInterface** to add code to the end of your constructor
    * Implement the **GetterHookInterface** to add code to your getter methods
    * Implement the **SetterBeforeValidationHookInterface** to add code to the beginning of your setter methods
    * Implement the **SetterAfterValidationHookInterface** to add code to the end of your setter methods
    * Implement the **SerializationHookInterface** to add code to the end of your serialization process

.. warning::

    If a setter for a property is called with the same value which is already stored internally (consequently no update of the property is required), the setters will return directly and as a result of that the setter hooks will not be executed.

    This behaviour also applies also to properties changed via the *populate* method added by the `PopulatePostProcessor <#populatepostprocessor>`__ and the *setAdditionalProperty* method added by the `AdditionalPropertiesAccessorPostProcessor <#additionalpropertiesaccessorpostprocessor>`__

To execute code before/after the processing of the schemas override the methods **preProcess** and **postProcess** inside your custom post processor.