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Quick Start

Forms are composed of elements and fieldsets. At the bare minimum, each element or fieldset requires a name; in most situations, you'll also provide some attributes to hint to the view layer how it might render the item. The form itself generally composes an InputFilter — which you can also create directly in the form via a factory. Individual elements can hint as to what defaults to use when generating a related input for the input filter.

Perform form validation by providing an array of data to the setData() method, and calling the isValid() method. If you want to simplify your work even more, you can bind an object to the form; on successful validation, it will be populated from the validated values.

Programmatic Form Creation

The following example demonstrates element, fieldset, and form creation, and how they are wired together.

use Laminas\Captcha;
use Laminas\Form\Element;
use Laminas\Form\Fieldset;
use Laminas\Form\Form;
use Laminas\InputFilter\Input;
use Laminas\InputFilter\InputFilter;

// Create a text element to capture the user name:
$name = new Element('name');
$name->setLabel('Your name');
$name->setAttributes([
    'type' => 'text',
]);

// Create a text element to capture the user email address:
$email = new Element\Email('email');
$email->setLabel('Your email address');

// Create a text element to capture the message subject:
$subject = new Element('subject');
$subject->setLabel('Subject');
$subject->setAttributes([
    'type' => 'text',
]);

// Create a textarea element to capture a message:
$message = new Element\Textarea('message');
$message->setLabel('Message');

// Create a CAPTCHA:
$captcha = new Element\Captcha('captcha');
$captcha->setCaptcha(new Captcha\Dumb());
$captcha->setLabel('Please verify you are human');

// Create a CSRF token:
$csrf = new Element\Csrf('security');

// Create a submit button:
$send = new Element('send');
$send->setValue('Submit');
$send->setAttributes([
    'type' => 'submit',
]);

// Create the form and add all elements:
$form = new Form('contact');
$form->add($name);
$form->add($email);
$form->add($subject);
$form->add($message);
$form->add($captcha);
$form->add($csrf);
$form->add($send);

// Create an input for the "name" element:
$nameInput = new Input('name');

/* ... configure the input, and create and configure all others ... */

// Create the input filter:
$inputFilter = new InputFilter();

// Attach inputs:
$inputFilter->add($nameInput);
/* ... */

// Attach the input filter to the form:
$form->setInputFilter($inputFilter);

As a demonstration of fieldsets, let's alter the above slightly. We'll create two fieldsets, one for the sender information, and another for the message details.

// Create the fieldset for sender details:
$sender = new Fieldset('sender');
$sender->add($name);
$sender->add($email);

// Create the fieldset for message details:
$details = new Fieldset('details');
$details->add($subject);
$details->add($message);

$form = new Form('contact');
$form->add($sender);
$form->add($details);
$form->add($captcha);
$form->add($csrf);
$form->add($send);

This manual approach gives maximum flexibility over form creation; however, it comes at the expense of verbosity. In the next section, we'll look at another approach.

Creation via Factory

You can create the entire form and input filter at once using the Factory. This is particularly nice if you want to store your forms as pure configuration; you can then pass the configuration to the factory and be done.

use Laminas\Form\Element;
use Laminas\Form\Factory;
use Laminas\Hydrator\ArraySerializable;

$factory = new Factory();
$form    = $factory->createForm([
    'hydrator' => ArraySerializable::class,
    'elements' => [
        [
            'spec' => [
                'name' => 'name',
                'options' => [
                    'label' => 'Your name',
                ],
                'type'  => 'Text',
            ],
        ],
        [
            'spec' => [
                'type' => Element\Email::class,
                'name' => 'email',
                'options' => [
                    'label' => 'Your email address',
                ]
            ],
        ],
        [
            'spec' => [
                'name' => 'subject',
                'options' => [
                    'label' => 'Subject',
                ],
                'type'  => 'Text',
            ],
        ],
        [
            'spec' => [
                'type' => Element\Textarea::class,
                'name' => 'message',
                'options' => [
                    'label' => 'Message',
                ]
            ],
        ],
        [
            'spec' => [
                'type' => Element\Captcha::class,
                'name' => 'captcha',
                'options' => [
                    'label' => 'Please verify you are human.',
                    'captcha' => [
                        'class' => 'Dumb',
                    ],
                ],
            ],
        ],
        [
            'spec' => [
                'type' => Element\Csrf::class,
                'name' => 'security',
            ],
        ],
        [
            'spec' => [
                'name' => 'send',
                'type'  => 'Submit',
                'attributes' => [
                    'value' => 'Submit',
                ],
            ],
        ],
    ],

    /* If we had fieldsets, they'd go here; fieldsets contain
     * "elements" and "fieldsets" keys, and potentially a "type"
     * key indicating the specific FieldsetInterface
     * implementation to use.
    'fieldsets' => [
    ],
     */

    // Configuration to pass on to
    // Laminas\InputFilter\Factory::createInputFilter()
    'input_filter' => [
        /* ... */
    ],
]);

If we wanted to use fieldsets, as we demonstrated in the previous example, we could do the following:

use Laminas\Form\Element;
use Laminas\Form\Factory;
use Laminas\Hydrator\ArraySerializable;

$factory = new Factory();
$form    = $factory->createForm([
    'hydrator'  => ArraySerializable::class,

    // Top-level fieldsets to define:
    'fieldsets' => [
        [
            'spec' => [
                'name' => 'sender',
                'elements' => [
                    [
                        'spec' => [
                            'name' => 'name',
                            'options' => [
                                'label' => 'Your name',
                            ],
                            'type' => 'Text'
                        ],
                    ],
                    [
                        'spec' => [
                            'type' => Element\Email::class,
                            'name' => 'email',
                            'options' => [
                                'label' => 'Your email address',
                            ],
                        ],
                    ],
                ],
            ],
        ],
        [
            'spec' => [
                'name' => 'details',
                'elements' => [
                    [
                        'spec' => [
                            'name' => 'subject',
                            'options' => [
                                'label' => 'Subject',
                            ],
                            'type' => 'Text',
                        ],
                    ],
                    [
                        'spec' => [
                            'name' => 'message',
                            'type' => Element\Textarea::class,
                            'options' => [
                                'label' => 'Message',
                            ],
                        ],
                    ],
                ],
            ],
        ],
    ],

    // You can specify an "elements" key explicitly:
    'elements' => [
        [
            'spec' => [
                'type' => Element\Captcha::class,
                'name' => 'captcha',
                'options' => [
                    'label' => 'Please verify you are human.',
                    'captcha' => [
                        'class' => 'Dumb',
                    ],
                ],
            ],
        ],
        [
            'spec' => [
            'type' => Element\Csrf::class,
            'name' => 'security',
        ],
    ],

    // But entries without string keys are also considered elements:
    [
        'spec' => [
            'name' => 'send',
            'type'  => 'Submit',
            'attributes' => [
                'value' => 'Submit',
            ],
        ],
    ],

    // Configuration to pass on to
    // Laminas\InputFilter\Factory::createInputFilter()
    'input_filter' => [
        /* ... */
    ],
]);

Note that the chief difference is nesting; otherwise, the information is basically the same.

The chief benefits to using the Factory are allowing you to store definitions in configuration, and usage of significant whitespace.

Factory-backed Form Extension

The default Form implementation is backed by the Factory. This allows you to extend it, and define your form internally. This has the benefit of allowing a mixture of programmatic and factory-backed creation, as well as defining a form for re-use in your application.

namespace Contact;

use Laminas\Captcha\AdapterInterface as CaptchaAdapter;
use Laminas\Form\Element;
use Laminas\Form\Form;

class ContactForm extends Form
{
    protected $captcha;

    public function __construct(CaptchaAdapter $captcha)
    {
        parent::__construct();

        $this->captcha = $captcha;

        // add() can take an Element/Fieldset instance, or a specification, from
        // which the appropriate object will be built.
        $this->add([
            'name' => 'name',
            'options' => [
                'label' => 'Your name',
            ],
            'type'  => 'Text',
        ]);
        $this->add([
            'type' => Element\Email::class,
            'name' => 'email',
            'options' => [
                'label' => 'Your email address',
            ],
        ]);
        $this->add([
            'name' => 'subject',
            'options' => [
                'label' => 'Subject',
            ],
            'type'  => 'Text',
        ]);
        $this->add([
            'type' => Element\Textarea::class,
            'name' => 'message',
            'options' => [
                'label' => 'Message',
            ],
        ]);
        $this->add([
            'type' => Element\Captcha::class,
            'name' => 'captcha',
            'options' => [
                'label' => 'Please verify you are human.',
                'captcha' => $this->captcha,
            ],
        ]);
        $this->add(new Element\Csrf('security'));
        $this->add([
            'name' => 'send',
            'type'  => 'Submit',
            'attributes' => [
                'value' => 'Submit',
            ],
        ]);

        // We could also define the input filter here, or
        // lazy-create it in the getInputFilter() method.
    }
}

In the above example, elements are added in the constructor. This is done to allow altering and/or configuring either the form or input filter factory instances, which could then have bearing on how elements, inputs, etc. are created. In this case, it also allows injection of the CAPTCHA adapter, allowing us to configure it elsewhere in our application and inject it into the form.

Validating Forms

Validating forms requires three steps. First, the form must have an input filter attached. Second, you must inject the data to validate into the form. Third, you validate the form. If invalid, you can retrieve the error messages, if any.

// assuming $captcha is an instance of some Laminas\Captcha\AdapterInterface:
$form = new Contact\ContactForm($captcha);

// If the form doesn't define an input filter by default, inject one.
$form->setInputFilter(new Contact\ContactFilter());

// Get the data. In an MVC application, you might try:
$data = $request->getPost();  // for POST data
$data = $request->getQuery(); // for GET (or query string) data

$form->setData($data);

// Validate the form
if ($form->isValid()) {
    $validatedData = $form->getData();
} else {
    $messages = $form->getMessages();
}

Always populate select elements with options

Always ensure that options for a select element are populated prior to validation; otherwise, the element will fail validation, and you will receive a NotInArray error message.

If you are populating the options from a database or other data source, make sure this is done prior to validation. Alternately, you may disable the InArray validator programmatically prior to validation:

$element->setDisableInArrayValidator(true);

You can get the raw data if you want, by accessing the composed input filter.

$filter = $form->getInputFilter();

$rawValues    = $filter->getRawValues();
$nameRawValue = $filter->getRawValue('name');

Hinting to the Input Filter

Often, you'll create elements that you expect to behave in the same way on each usage, and for which you'll want specific filters or validation as well. Since the input filter is a separate object, how can you achieve these latter points?

Because the default form implementation composes a factory, and the default factory composes an input filter factory, you can have your elements and/or fieldsets hint to the input filter. If no input or input filter is provided in the input filter for that element, these hints will be retrieved and used to create them.

To do so, one of the following must occur. For elements, they must implement Laminas\InputFilter\InputProviderInterface, which defines a getInputSpecification() method; for fieldsets (and, by extension, forms), they must implement Laminas\InputFilter\InputFilterProviderInterface, which defines a getInputFilterSpecification() method.

In the case of an element, the getInputSpecification() method should return data to be used by the input filter factory to create an input. Every HTML5 (email, url, color, etc.) element has a built-in element that uses this logic. For instance, here is how the Laminas\Form\Element\Color element is defined:

namespace Laminas\Form\Element;

use Laminas\Filter;
use Laminas\Form\Element;
use Laminas\InputFilter\InputProviderInterface;
use Laminas\Validator\Regex as RegexValidator;
use Laminas\Validator\ValidatorInterface;

class Color extends Element implements InputProviderInterface
{
    /**
     * Seed attributes
     *
     * @var array
     */
    protected $attributes = [
        'type' => 'color',
    ];

    /**
     * @var ValidatorInterface
     */
    protected $validator;

    /**
     * Get validator
     *
     * @return ValidatorInterface
     */
    protected function getValidator()
    {
        if (null === $this->validator) {
            $this->validator = new RegexValidator('/^#[0-9a-fA-F]{6}$/');
        }
        return $this->validator;
    }

    /**
     * Provide default input rules for this element
     *
     * Attaches an email validator.
     *
     * @return array
     */
    public function getInputSpecification()
    {
        return [
            'name' => $this->getName(),
            'required' => true,
            'filters' => [
                ['name' => Filter\StringTrim::class],
                ['name' => Filter\StringToLower::class],
            ],
            'validators' => [
                $this->getValidator(),
            ],
        ];
    }
}

The above hints to the input filter to create and attach an input named after the element, marking it as required, giving it StringTrim and StringToLower filters, and defining a Regex validator. Note that you can either rely on the input filter to create filters and validators, or directly instantiate them.

For fieldsets, you do very similarly; the difference is that getInputFilterSpecification() must return configuration for an input filter.

namespace Contact\Form;

use Laminas\Filter;
use Laminas\Form\Fieldset;
use Laminas\InputFilter\InputFilterProviderInterface;
use Laminas\Validator;

class SenderFieldset extends Fieldset implements InputFilterProviderInterface
{
    public function getInputFilterSpecification()
    {
        return [
            'name' => [
                'required' => true,
                'filters'  => [
                    ['name' => Filter\StringTrim::class],
                ],
                'validators' => [
                    [
                        'name' => Validator\StringLength::class,
                        'options' => [
                            'min' => 3,
                            'max' => 256
                        ],
                    ],
                ],
            ],
            'email' => [
                'required' => true,
                'filters'  => [
                    ['name' => Filter\StringTrim::class],
                ],
                'validators' => [
                    new Validator\EmailAddress(),
                ],
            ],
        ];
    }
}

Specifications are a great way to make forms, fieldsets, and elements re-usable trivially in your applications. In fact, the Captcha and Csrf elements define specifications in order to ensure they can work without additional user configuration!

Use the most specific input type

If you set custom input filter specification either in getInputSpecification() or in getInputFilterSpecification(), the Laminas\InputFilter\InputInterface set for that specific field is reset to the default Laminas\InputFilter\Input.

Some form elements may need a particular input filter, like Laminas\Form\Element\File: in this case it's mandatory to specify the type key in your custom specification to match the original one (e.g., for the file element, use Laminas\InputFilter\FileInput).

Binding an object

As noted in the introduction, forms bridge the domain model and the view layer. Let's see that in action.

When you bind() an object to the form, the following happens:

  • The composed Hydrator calls extract() on the object, and uses the values returned, if any, to populate the value attributes of all elements. If a form contains a fieldset that itself contains another fieldset, the form will recursively extract the values.
  • When isValid() is called, if setData() has not been previously set, the form uses the composed Hydrator to extract values from the object, and uses those during validation.
  • If isValid() is successful (and the bindOnValidate flag is enabled, which is true by default), then the Hydrator will be passed the validated values to use to hydrate the bound object. (If you do not want this behavior, call setBindOnValidate(FormInterface::BIND_MANUAL)).
  • If the object implements Laminas\InputFilter\InputFilterAwareInterface, the input filter it composes will be used instead of the one composed on the form.

This is easier to understand with an example.

$contact = new ArrayObject;
$contact['subject'] = '[Contact Form] ';
$contact['message'] = 'Type your message here';

$form = new Contact\ContactForm;

$form->bind($contact); // form now has default values for
                       // 'subject' and 'message'

$data = [
    'name'    => 'John Doe',
    'email'   => 'j.doe@example.tld',
    'subject' => '[Contact Form] \'sup?',
];
$form->setData($data);

if ($form->isValid()) {
    // $contact now has the following structure:
    // [
    //     'name'    => 'John Doe',
    //     'email'   => 'j.doe@example.tld',
    //     'subject' => '[Contact Form] \'sup?',
    //     'message' => 'Type your message here',
    // ]
    // But is an ArrayObject instance!
}

When an object is bound to the form, calling getData() will return that object by default. If you want to return an associative array instead, you can pass the FormInterface::VALUES_AS_ARRAY flag to the method.

use Laminas\Form\FormInterface;
$data = $form->getData(FormInterface::VALUES_AS_ARRAY);

Laminas ships several standard hydrators; you can create custom hydrators by implementing Laminas\Hydrator\HydratorInterface, which looks like this:

namespace Laminas\Hydrator;

interface HydratorInterface
{
    /** @return array */
    public function extract($object);
    public function hydrate(array $data, $object);
}

Rendering

As noted previously, forms are meant to bridge the domain model and view layer. We've discussed the domain model binding, but what about the view?

The form component ships a set of form-specific view helpers. These accept the various form objects, and introspect them in order to generate markup. Typically, they will inspect the attributes, but in special cases, they may look at other properties and composed objects.

When preparing to render, you will generally want to call prepare(). This method ensures that certain injections are done, and ensures that elements nested in fieldsets and collections generate names in array notation (e.g., scoped[array][notation]).

The base view helpers used everywhere are Form, FormElement, FormLabel, and FormElementErrors. Let's use them to display the contact form.

<?php
// within a view script
$form = $this->form;
$form->prepare();

// Assuming the "contact/process" route exists...
$form->setAttribute('action', $this->url('contact/process'));

// Set the method attribute for the form
$form->setAttribute('method', 'post');

// Get the form label plugin
$formLabel = $this->plugin('formLabel');

// Render the opening tag
echo $this->form()->openTag($form);
?>
<div class="form_element">
<?php
    $name = $form->get('name');
    echo $formLabel->openTag() . $name->getOption('label');
    echo $this->formInput($name);
    echo $this->formElementErrors($name);
    echo $formLabel->closeTag();
?></div>

<div class="form_element">
<?php
    $subject = $form->get('subject');
    echo $formLabel->openTag() . $subject->getOption('label');
    echo $this->formInput($subject);
    echo $this->formElementErrors($subject);
    echo $formLabel->closeTag();
?></div>

<div class="form_element">
<?php
    $message = $form->get('message');
    echo $formLabel->openTag() . $message->getOption('label');
    echo $this->formTextarea($message);
    echo $this->formElementErrors($message);
    echo $formLabel->closeTag();
?></div>

<div class="form_element">
<?php
    $captcha = $form->get('captcha');
    echo $formLabel->openTag() . $captcha->getOption('label');
    echo $this->formCaptcha($captcha);
    echo $this->formElementErrors($captcha);
    echo $formLabel->closeTag();
?></div>

<?= $this->formElement($form->get('security')) ?>
<?= $this->formElement($form->get('send')) ?>

<?= $this->form()->closeTag() ?>

There are a few things to note about this. First, to prevent confusion in IDEs and editors when syntax highlighting, we use helpers to both open and close the form and label tags. Second, there's a lot of repetition happening here; we could easily create a partial view script or a composite helper to reduce boilerplate. Third, note that not all elements are created equal — the CSRF and submit elements don't need labels or error messages. Finally, note that the FormElement helper tries to do the right thing — it delegates actual markup generation to other view helpers. However, it can only guess what specific form helper to delegate to based on the list it has. If you introduce new form view helpers, you'll need to extend the FormElement helper, or create your own.

Following the example above, your view files can quickly become long and repetitive to write. While we do not currently provide a single-line form view helper (as this reduces the form customization), we do provide convenience wrappers around emitting individual elements via the FormRow view helper, and collections of elements (Laminas\Form\Element\Collection, Laminas\Form\Fieldset, or Laminas\Form\Form) via the FormCollection view helper (which, internally, iterates the collection and calls FormRow for each element, recursively following collections).

The FormRow view helper automatically renders a label (if present), the element itself using the FormElement helper, as well as any errors that could arise. Here is the previous form, rewritten to take advantage of this helper:

<?php
// within a view script
$form = $this->form;
$form->prepare();

// Assuming the "contact/process" route exists...
$form->setAttribute('action', $this->url('contact/process'));

// Set the method attribute for the form
$form->setAttribute('method', 'post');

// Render the opening tag
echo $this->form()->openTag($form);
?>
<div class="form_element">
    <?= $this->formRow($form->get('name')) ?>
</div>

<div class="form_element">
    <?= $this->formRow($form->get('subject')) ?>
</div>

<div class="form_element">
    <?= $this->formRow($form->get('message')) ?>
</div>

<div class="form_element">
    <?= $this->formRow($form->get('captcha')) ?>
</div>

<?= $this->formElement($form->get('security')) ?>
<?= $this->formElement($form->get('send')) ?>

<?= $this->form()->closeTag() ?>

Note that FormRow helper automatically prepends the label. If you want it to be rendered after the element itself, you can pass an optional parameter to the FormRow view helper :

<div class="form_element">
    <?= $this->formRow($form->get('name'), 'append') ?>
</div>

As noted previously, the FormCollection view helper will iterate any collection — including Laminas\Form\Element\Collection, fieldsets, and forms — emitting each element discovered using FormRow. FormCollection does not render fieldset or form tags; you will be responsible for emitting those yourself.

The above examples can now be rewritten again:

<?php
// within a view script
$form = $this->form;
$form->prepare();

// Assuming the "contact/process" route exists...
$form->setAttribute('action', $this->url('contact/process'));

// Set the method attribute for the form
$form->setAttribute('method', 'post');

// Render the opening tag
echo $this->form()->openTag($form);
echo $this->formCollection($form);
echo $this->form()->closeTag();

Finally, the Form view helper can optionally accept a Laminas\Form\Form instance; if provided, it will prepare the form, iterate it, and render all elements using either FormRow (for non-collection elements) or FormCollection (for collections and fieldsets):

<?php
// within a view script
$form = $this->form;

// Assuming the "contact/process" route exists...
$form->setAttribute('action', $this->url('contact/process'));

// Set the method attribute for the form
$form->setAttribute('method', 'post');

echo $this->form($form);

One important point to note about the last two examples: while they greatly simplifies emitting the form, you also lose most customization opportunities. The above, for example, will not include the <div class="form_element"></div> wrappers from the previous examples! As such, you will generally want to use this facility only when prototyping.

Taking advantage of HTML5 input attributes

HTML5 brings a lot of exciting features, one of them being simplified client form validations. laminas-form provides elements corresponding to the various HTML5 elements, specifying the client-side attributes required by them. Additionally, each implements InputProviderInterface, ensuring that your input filter will have reasonable default validation and filtering rules that mimic the client-side validations.

Always validate server-side

Although client validation is nice from a user experience point of view, it must be used in addition to server-side validation, as client validation can be easily bypassed.

Validation Groups

Sometimes you want to validate only a subset of form elements. As an example, let's say we're re-using our contact form over a web service; in this case, the Csrf, Captcha, and submit button elements are not of interest, and shouldn't be validated.

laminas-form provides a proxy method to the underlying InputFilter's setValidationGroup() method, allowing us to perform this operation.

$form->setValidationGroup('name', 'email', 'subject', 'message');
$form->setData($data);
if ($form->isValid()) {
    // Contains only the "name", "email", "subject", and "message" values
    $data = $form->getData();
}

If you later want to reset the form to validate all elements, pass the FormInterface::VALIDATE_ALL flag to the setValidationGroup() method:

use Laminas\Form\FormInterface;
$form->setValidationGroup(FormInterface::VALIDATE_ALL);

When your form contains nested fieldsets, you can use an array notation to validate only a subset of the fieldsets :

$form->setValidationGroup(['profile' => [
    'firstname',
    'lastname',
] ]);

$form->setData($data);
if ($form->isValid()) {
    // Contains only the "firstname" and "lastname" values from the
    // "profile" fieldset
    $data = $form->getData();
}

Using Annotations

Creating a complete form solution can often be tedious: you'll create a domain model object, an input filter for validating it, a form object for providing a representation for it, and potentially a hydrator for mapping the form elements and fieldsets to the domain model. Wouldn't it be nice to have a central place to define all of these?

Annotations allow us to solve this problem. You can define the following behaviors with the shipped annotations in laminas-form:

  • AllowEmpty: mark an input as allowing an empty value. This annotation does not require a value.
  • Attributes: specify the form, fieldset, or element attributes. This annotation requires an associative array of values, in a JSON object format: @Attributes({"class":"laminas_form","type":"text"}).
  • ComposedObject: specify another object with annotations to parse. Typically, this is used if a property references another object, which will then be added to your form as an additional fieldset. Expects a string value indicating the class for the object being composed: @ComposedObject("Namespace\Model\ComposedObject"); or an array to compose a collection: @ComposedObject({ "target_object":"Namespace\Model\ComposedCollection", "is_collection":"true", "options":{"count":2}}); target_object is the element to compose, is_collection flags this as a collection, and options can take an array of options to pass into the collection.
  • ErrorMessage: specify the error message to return for an element in the case of a failed validation. Expects a string value.
  • Exclude: mark a property to exclude from the form or fieldset. This annotation does not require a value.
  • Filter: provide a specification for a filter to use on a given element. Expects an associative array of values, with a "name" key pointing to a string filter name, and an "options" key pointing to an associative array of filter options for the constructor: @Filter({"name": "Boolean", "options": {"casting":true}}). This annotation may be specified multiple times.
  • Flags: flags to pass to the fieldset or form composing an element or fieldset; these are usually used to specify the name or priority. The annotation expects an associative array: @Flags({"priority": 100}).
  • Hydrator: specify the hydrator class to use for this given form or fieldset. A string value is expected.
  • InputFilter: specify the input filter class to use for this given form or fieldset. A string value is expected.
  • Input: specify the input class to use for this given element. A string value is expected.
  • Instance: specify an object class instance to bind to the form or fieldset.
  • Name: specify the name of the current element, fieldset, or form. A string value is expected.
  • Object: specify an object class instance to bind to the form or fieldset. (Note: this is deprecated in 2.4.0; use Instance instead.)
  • Options: options to pass to the fieldset or form that are used to inform behavior — things that are not attributes; e.g. labels, CAPTCHA adapters, etc. The annotation expects an associative array: @Options({"label": "Username:"}).
  • Required: indicate whether an element is required. A boolean value is expected. By default, all elements are required, so this annotation is mainly present to allow disabling a requirement.
  • Type: indicate the class to use for the current element, fieldset, or form. A string value is expected.
  • Validator: provide a specification for a validator to use on a given element. Expects an associative array of values, with a "name" key pointing to a string validator name, and an "options" key pointing to an associative array of validator options for the constructor: @Validator({"name": "StringLength", "options": {"min":3, "max": 25}}). This annotation may be specified multiple times.
  • ContinueIfEmpty: indicate whether the element can be submitted when it is empty. A boolean value is expected. If @Required is set to false, this needs to be set to true to allow the field to be empty.

To use annotations, include them in your class and/or property docblocks. Annotation names will be resolved according to the import statements in your class; as such, you can make them as long or as short as you want depending on what you import.

doctrine/common dependency

Form annotations require doctrine\common, which contains an annotation parsing engine. Install it using composer:

$ composer require doctrine/common

Here's an example:

use Laminas\Form\Annotation;

/**
 * @Annotation\Name("user")
 * @Annotation\Hydrator("Laminas\Hydrator\ObjectProperty")
 */
class User
{
    /**
     * @Annotation\Exclude()
     */
    public $id;

    /**
     * @Annotation\Filter({"name":"StringTrim"})
     * @Annotation\Validator({"name":"StringLength", "options":{"min":1, "max":25}})
     * @Annotation\Validator({"name":"Regex",
"options":{"pattern":"/^[a-zA-Z][a-zA-Z0-9_-]{0,24}$/"}})
     * @Annotation\Attributes({"type":"text"})
     * @Annotation\Options({"label":"Username:"})
     */
    public $username;

    /**
     * @Annotation\Type("Laminas\Form\Element\Email")
     * @Annotation\Options({"label":"Your email address:"})
     */
    public $email;
}

The above will hint to the annotation builder to create a form with name "user", which uses the hydrator Laminas\Hydrator\ObjectProperty. That form will have two elements, "username" and "email". The "username" element will have an associated input that has a StringTrim filter, and two validators: a StringLength validator indicating the username is between 1 and 25 characters, and a Regex validator asserting it follows a specific accepted pattern. The form element itself will have an attribute "type" with value "text" (a text element), and a label "Username:". The "email" element will be of type Laminas\Form\Element\Email, and have the label "Your email address:".

To use the above, we need Laminas\Form\Annotation\AnnotationBuilder:

use Laminas\Form\Annotation\AnnotationBuilder;

$builder = new AnnotationBuilder();
$form    = $builder->createForm(User::class);

At this point, you have a form with the appropriate hydrator attached, an input filter with the appropriate inputs, and all elements.

You're not done

In all likelihood, you'll need to add some more elements to the form you construct. For example, you'll want a submit button, and likely a CSRF-protection element. We recommend creating a fieldset with common elements such as these that you can then attach to the form you build via annotations.