Writing custom form elements

Question

Writing custom form elements

ias2 Jun '17

Created Jun '17	Last Reply May '20	Replies 1	Views 823	Votes 0

ias2 1.5k

Jun '17

Hi, I'm writing a new custom Element to use in Phalcon generated forms. This is my element code:

<?php
  namespace MyNameSpace\MyElementLocation;

  use Phalcon\Forms\Element;

  class Dummy extends Element
  {
    public function render($attributes = null)
    {
      $html = '<pre>' . print_r($attributes, true) . '</pre>';

      return $html;
    }
  }
?>

as you can see, it's only a test. To use it, I wrote this code:

<?php
  // namespace and other init stuff.

  class CustomElementTestForm extends Form
  {
    public function initialize($entity = null, $options = null)
    {
      $this->add(new Dummy('dummy', ['foo' => 'bar']));
    }
  }
?>

the problem is that the $attributes array in the custom element code contains no data, even i've used an array as function parameter in then test code ($html is always equal to '<pre></pre>')... suggestions on what I'm missing?

danseciu
935

Accepted
answer

Jul '17

I'm guessing you're rendering the form element as follows:

$form = new CustomElementTestForm();
$form->render('dummy-el');

In order to get the default attributes you'll need to use $this->getAttributes() in the render method:

public function render($attributes = null)
{
    $html = '<pre>' . print_r($this->getAttributes(), true) . '</pre>';
    return $html;
}

The $attributes parameter contains attributes passed directly to the render method:

$form = new CustomElementTestForm();
$form->render('dummy-el', ['class' => 'my-class']);

A better solution would be to implement both of these options:

public function render($attributes = null)
{
    if(!$attributes) {
        $attributes = $this->getAttributes();
    }

    $html = '<pre>' . print_r($attributes, true) . '</pre>';

    return $html;
}

ias2 · Answer 1 · 2017-07-15T03:13:04-07:00

Your "better solution" works great, thanks! In the meantime, I've uset custom tags to acheive the same result but using custom elements is better for a more consistent project design.