Making Silverstripe Modules fit for purpose

_config.php

<?php

//..
// below we are updating the private static `my_array_static` in 
// the `MyClassName` class.
// Because it is an array, you can only add additional entries to the 
// end of the array, if you are keen to add a new entry at the beginning
// or, for example, remove one entry - then this is the way to go.
$newArray = array(
    'A',
    'B',
    'C'
);
Config::inst()->update(
    'MyClassName', 
    'my_array_static', 
    $newArray
);


Object::useCustomClass('MyModuleClass', 'MyClass');

ExampleBuildTask.php

<?php

class ExampleBuildTask extends BuildTask
{

    protected $title = 'Add more data to our example';

    protected $description = 'Takes the Example Objects and populates the example fields';

    protected $enabled = true;

    public function run($request) 
    {   
        
        //.. take the Example Objects and populates the example fields here
        
    	DB::alteration_message('Done now');
    }
}

MyModuleClassExtension.php

<?php

class MyModuleClassExtension extends DataExtension
{
  
    private static $db = array(
        'MyAdditionalField' => 'HTMLText'
    );
    
    function updateCMSFields(FieldList $fields) {
        $fields->removeFieldFromTab('Root.Main', 'Content');
    }
}

MyPageWhichExtendsModulePage.php

<?php

class MyPageWhichExtendsModulePage extends ModulePage 
{
//..
}

class MyPageWhichExtendsModulePage_Controller extends ModulePage_Controller 
{
    function init()
    {
        parent::init();
        //block a CSS file
        Requirements::block('module_name/css/FancyModuleCSS.css');
        //replace a JS file
        Requirements::block('module_name/javascript/FancyModuleJS.js');
        Requirements::javascript('themes/themename_module_name/javascript/FancyModuleJS.js');
    }
}

mysite._config.module-name.yml

---
Name: module_name_fixes
After: 'framework/*','cms/*', ‘module-name/*’
---
#set a variable
MyClass:
  my_private_static_var: 21
  
# use a custom class
Injector:
  ModuleClass:
    class: MyClass
    
ModuleClass:
  extensions:
    - MyModuleClassExtension

---
Only:
  environment: 'dev'
---

SSViewer:
  source_file_comments: true
    

mysite.code.model.MyDataObject.php

<?php

class MyDataObject extends DataObject {

  /**
   * this method can be added to any 
   * page type and/or DataObject
   * and it will run every time you do a dev/build
   */
  function requireDefaultRecords()
  {
    parent::requireDefaultRecords();
    DB::alteration_message('Setting first MyDataObject.Foo to Bar to make it shine', 'created');
    $myObject = MyDataObject::get()->first();
    $myObject->Foo = 'bar';
    $myObject->write();
  }
}

mysite.lang-en.yml

en:
  LeftAndMain:
    PERMALREADY: ‘Sorry, but the CMS is not for you.'