How to use InputFilterManager to construct custom InputFilters in Zf2

Question

ZF2 documentation says following on defult services documentation;

InputFilterManager, mapping to Zend\Mvc\Service\InputFilterManagerFactory. This creates and returns an instance of Zend\InputFilter\InputFilterPluginManager, which can be used to manage and persist input filter instances.

I have a custom zf2 inputfilter class and i'm adding filters and validators inside init() method like following;

namespace Application\Filter;
use Zend\InputFilter\InputFilter;

class GlassFilter extends InputFilter
{
    public function init()
    {
        $this->add(array(
                'name' => 'glassname',
                'required' => true,
                'filters' => array(
                    array('name' => 'StringToUpper'),
                ),
                'validators' => array(
                    array( 'name' => 'StringLength', 'options' => array('min' => 3),
                ),
        ));
}

Also i added following key to my module.config.php

'filters' => array(
    'invokables' => array(
        'glassfilter' => '\Application\Filter\GlassFilter',
    ),
),

My question is, how can i construct my GlassFilter using InputFilterManager? Is this a correct approach? I found this thread but i want to understand relation between custom InputFilters and InputFilterManager.

Answer 1

Ok, after spending 3 bloody hours (thanks to incredible(!) documentation) I figured it out. I'm writing my solution as an answer, hopefully it will help others who want to write their custom inputfilters.

1. You should register your custom inputfilter in module.config.php by input_filters top key, not filter, filters, filter_manger, filtermanager etc..
2. Extend default Zend\InputFilter\InputFilter when writing your own GlassFilter.
3. Write your filters inside the init() method of GlassFilter, not in the __constructor(). It will be called automatically after construction.
4. Then get it anywhere via inputfiltermanager, not servicemanager directly.

Config example:

'input_filters' => array(
    'invokables' => array(
        'glassfilter' => '\Application\Filter\GlassFilter',
     ),
),

Usage example:

$glassfilter = $serviceLocator->get('InputFilterManager')->get('glassfilter');