CODEWITHSUNDEEP
phpsymfonysymfony-forms
Sergio Negri
Sergio Negri

Reputation: 2063

Symfony2 dynamically assign attr to form field

I'm in a situation where I want to be able to dynamically set the required=true/false option or the array(...other stuff..., 'class' => ' hidden') of a form field.

The context is the following: there is a "Project" entity with some fields. When I create other entities with forms I want to check some attributes of the Project entity and make decisions on the visibility/requiredness of certain fields of the entity I'm creating.

For example if a Project is with attribute "timePressure=high" then a field of a given entity is not required (but is visible). If there are other conditions it becomes invisible etc...

So basically I was hoping to call a function inside each ->add() of the form builder to spit out the relevant portions (e.g. that function would return a string with "required=true" or the other related to the hidden class). The thing is that the function should take as arguments: the projectID (ok, this can be passed as options of the form builder), the class and the field we are talking about to decide. I was envisioning something like:

->add('background', 'textarea', array('attr' => array('rows' => 4, functionToDecideIfInvisible($projectId)), functionToDecideRequiredness($projectId)))

The two function would return the string 'class' => ' hidden' and required=true (or false)

I'd like to avoid to having to specify the field name (in this case background) to avoid code repetition.

Can this be done?

Other suggestions on how to solve the thing?

Thank you!

SN

Upvotes: 0

Views: 1327

Answers (2)

Sergio Negri
Sergio Negri

Reputation: 2063

I found a way to do it.

My add would be like:

->add('background', 'textarea', array_merge($this->vr->fieldReq(get_class($this), 
'background', $projectID), array('attr' => array_merge(array('rows' => 4, ),
$this->vr->fieldCssClass(get_class($this), 'background', $projectID) ) )))

To do that I had to define the form as service, plus I created another class as service (the one which holds the two methods I need).

This is the class:

class FieldReqAndCssClass
{
public function fieldReq($parentEntity, $field, $projectID)
    {
    $required = array();
    $required['required'] = false; //do stuff on the database instead of setting it to false hardcoded
    return $required;
    }

public function fieldCssClass($parentEntity, $field, $projectID)
    {
    $cssClass= array();
    //do stuff on the database instead of setting the class as hidden hardcoded
    //$cssClass['class'] = ' hidden';
    $cssClass['class'] = '';
    return $cssClass;
    }
}

Of course in my form I had to:

public function __construct(\AppBundle\Util\FieldReqAndCssClass $fieldReqAndCssClass)
{
$this->vr = $fieldReqAndCssClass; // vr stands for visibility and requiredness
}

And these are the two services:

app_bundle.field_req_and_css_class:
    class: AppBundle\Util\FieldReqAndCssClass
    arguments: []

app_bundle.form.type.projectdetail:
    class: AppBundle\Form\Type\ProjectDetailFormType
    arguments: [@app_bundle.field_req_and_css_class]
    tags:
        - { name: form.type, alias: ProjectDetail }

Of course here in the first service I'll need to inject the entity manager and add it to the construct, and probably also in the form service, but the basic skeleton is working :)

I'm a happy man :)

EDIT The only problem of the above is that it makes hidden the widget but not the label. To fix it:

->add('background', 'textarea', array_merge($vr->fieldReq($myClass,
'background', $project), array('label_attr' => $vr->fieldCssClass($myClass, 
'background', $project),'attr' => array_merge(array('rows' => 4, ), 
$vr->fieldCssClass($myClass, 'background', $project) ) )))

Obviously before I have to declare:

$myClass = get_class($this);
$vr = $this->vr;

Upvotes: -1

Marin Bînzari
Marin Bînzari

Reputation: 5348

What you need are Form Events: http://symfony.com/doc/current/cookbook/form/dynamic_form_modification.html#cookbook-form-events-underlying-data

They allow you to modify your form based on your data.

You create you project form in the controller:

$form = $this->createForm(new ProjectType(), $project, array(
    'action' => $this->generateUrl('project.edit'),
    'method' => 'POST',
));

Then you add the FormEvents::PRE_SET_DATA listener:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
        $project = $event->getData();
        $form = $event->getForm();

        // check timePressure on the Project object
        if ('high' === $project->timePressure) {
            $form->add('timePressure', 'text', array(
                'required' => false
            );
        }
    });
}

Upvotes: 2

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