Is it ok to define main logic in block constructor?

Question

I would love to be sure, if it is not a ugly practice to do the following.

In my controller I render a block template layout:

    public function saveactionAction() {
        $this->loadLayout();
        $this->rendereLayout();
    }

Render some simple HTML form for saving:

    <form action="" method="POST">
        <input name="somevar" type="text">
        <input type="submit">
    </form>

and in my block's template, I receive a form data, filter it and save it in the constructor:

 class MyModule_MyCompany_Block_SaveAction extends Mage_Core_Block_Template {

        public function __construct() {
            if($params = $this->getRequest()->getParams()){

                // custom filtering and saving to data database
            }
            parent::__constuct();
        }
    }

The question is: is it normal or should I do the logic inside the controller preferably?

Answer 1

The short answer is "no" but I will provide some arguments.

The block script is to define everything that is linked with the display of the block. Filtering can be one action that can be done in there.

The controller makes the link between view and models. The assertion that you can do custom filtering and saving to data database is half false as you can do the filtering in controller but all the logic that involve database should be done with the help of models (both basic and resource ones). The controller should only call these models. Moreover, prefer the functions like indexAction() to do the logic than the constructor in controller and elsewhere.

The basic model has a large amount of tools that permits to retrieve easily data from the database without calling resource's models.

The resource and collections permit to retrieve data from database.