Zend\Form\Select and empty options

Questions Components & MVC
1

Hi folks,

I’ve got a form that uses a Select element with the empty_option set.

The form is bound to an object.

When the POST comes in with the empty option selected, that’s a value of “” (empty string) in HTML-land. Single-stepping through bind, populateValues, and friends, that value stays all the way through the process, and my object’s setProperty gets called with the empty string.

Is there a canonical way to convert that empty string to null so that by the time setProperty gets called, a null is passed in? Is that the hydrator’s job?

2

Ah, or maybe Zend\Filter\ToNull

But seems like too common a need to not be built-in somewhere.

3

:+1:

No, at the moment the empty option is only used for the output. It would be a feature request, but with a BC break. The current behaviour with the empty string is different.

4

Would it be a BC break if it were just an option like ‘use_null_for_empty’ ?

The resulting code in my entity doesn’t seem to be too different from just testing for an empty string. My type hints can stay intact, which adds to expressiveness I guess…

public function setSupersedes(Competency $competency = null)
{
    if (null === $competency)   {
        if ($this->supersedes) {
            $this->supersedes->setSupersededBy();
        }
        $this->supersedes = null;
    } else {
        $this->supersedes = $competency;
        $competency->setSupersededBy($this);
    }
}
5

Please keep in mind, bloating the class with more options means:

  • more code to maintain
  • more tests
  • more documentation
  • more areas for problems
  • more which the user has to know
  • …

At the moment the current behaviour adapted the normal usage with POST values in PHP. Compare with all other text elements.
If you need something different, then add your own input-filter specification.

6

Beaut, thanks for the discussion @froschdesign