Forms¶

Overview¶

Phalcon offers a components under the Phalcon\Forms namespace that help developers create and maintain forms that can be used to render HTML elements on screen but also perform validations on the input from those elements.

<?php

use Phalcon\Forms\Form;
use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Element\Select;

$form = new Form();

$form->add(
    new Text(
        'nameLast'
    )
);

$form->add(
    new Text(
        'nameFirst'
    )
);

$form->add(
    new Select(
        'phoneType',
        [
            1 => 'Home',
            2 => 'Work',
            3 => 'Mobile',
        ]
    )
);

In the template:

<h1>
    Contacts
</h1>

<form method='post'>

    <p>
        <label>
            Last Name
        </label>

        <?php echo $form->render('nameLast'); ?>
    </p>

    <p>
        <label>
            First Name
        </label>

        <?php echo $form->render('nameFirst'); ?>
    </p>

    <p>
        <label>
            Gender
        </label>

        <?php echo $form->render('phoneType'); ?>
    </p>

    <p>
        <input type='submit' value='Save' />
    </p>

</form>

Each element in the form can be rendered as required by the developer. Internally, Phalcon\Tag is used to produce the correct HTML for each element and you can pass additional HTML attributes as the second parameter of render():

<p>
    <label>
        Name
    </label>

    <?php 
        echo $form->render(
            'nameFirst', 
            [
                'maxlength'   => 30, 
                'placeholder' => 'First Name',
            ]
        ); ?>
</p>

HTML attributes also can be set in the element's definition:

<?php

use Phalcon\Forms\Form;

$form = new Form();

$form->add(
    new Text(
        'nameFirst',
        [
            'maxlength'   => 30, 
            'placeholder' => 'First Name',
        ]
    )
);

Methods¶

Phalcon\Forms\Form exposes a number of methods that help with setting up a form with the necessary elements so that it can be used for validation, rendering elements etc.

public function __construct(
    mixed $entity = null, 
    array $userOptions = []
)

Constructor. Accepts optionally an entity object which will be read internally. If the properties of the object contain properties that match the names of the elements defined in the form, those elements will be populated with the values of the corresponding properties of the entity. The entity can be an object such as a Phalcon\Mvc\Model or even a \stdClass. The second parameter is userOptions an optional array with user defined data.

NOTE

If the form has the initialize method present, the constructor will call it automatically with the same parameters

<?php

use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Element\Select;
use Phalcon\Forms\Form;

$form = new Form(
    null,
    [
        'phoneTypes' => [
            1 => 'Home',
            2 => 'Work',
            3 => 'Mobile',
        ],
    ]
);

$form->add(
    new Text(
        'nameLast'
    )
);

$form->add(
    new Text(
        'nameFirst'
    )
);

$options    = $this->getUserOptions();
$phoneTypes = $options['phoneTypes'] ?? [];
$form->add(
    new Select(
        'phoneType',
        $phoneTypes
    )
);

If the entity is passed and it is not an object, a Phalcon\Forms\Exception will be thrown.

public function add(
    ElementInterface $element, 
    string $position = null, 
    bool $type = null
): Form

Adds an element to the form. The first parameter is an ElementInterface object. The second parameter position (if defined) is the name of the existing element we are targeting. The third boolean parameter type if set to true the new element will be added before the element defined in position. If not set or set to null/false, the new element will be added after the one defined by the position parameter.

public function bind(
    array $data, 
    mixed $entity, 
    array $whitelist = []
): Form

Binds data to the entity. The first parameter data is an array of key/values. This usually is the $_POST array. The second parameter entity is an entity object. If the properties of the entity object contain properties that match the names of the dataelements defined in the form, those elements will be populated with the values of the corresponding properties of the entity. The entity can be an object such as a Phalcon\Mvc\Model or even a \stdClass. The third parameter whitelist is an array of whitelisted elements. Any element in the whitelist array that has the same name as an element in the data array will be ignored.

The bind method takes the first array (e.g $_POST) and an entity object (e.g. Invoices). It loops through the array and if it finds an array key that exists in the form, it applies the necessary filters (defined in the form) to the value of the array. After that, it checks the entity object (Invoices) and assigns this value to any property that matches the array key. If a method exists as a setter with the same name as an array key, it will be called first (i.e. name -> setName()). This method allows us to quickly filter input and assign this input to the passed entity object.

<?php

$form->bind($_POST, $customer);

if (true === $form->isValid()) {
    $customer->save();
}

If there are no elements in the form, a Phalcon\Forms\Exception will be thrown.

public function clear(mixed $fields = null): Form

Clears every element in the form to its default value. If the passed parameter fields is a string, only that field will will be cleared. If an array is passed, all elements in the array will be cleared. Finally, if nothing is passed, all fields will be cleared.

public function count(): int

Returns the number of elements in the form

public function current(): ElementInterface | bool

Returns the current element in the iterator

public function get(string $name): ElementInterface

Returns an element added to the form by its name. If the element is not found in the form, a Phalcon\Forms\Exception will be thrown.

public function getAction(): string

Returns the form's action

public function getAttributes(): Attributes

Returns the form's attributes collection. The object returned is Phalcon\Html\Attributes.

public function getElements(): ElementInterface[]

Returns the form elements added to the form

public function getEntity()

Returns the entity related to the model

public function getLabel(string $name): string

Returns a label for an element. If the element is not found in the form, a Phalcon\Forms\Exception will be thrown.

public function getMessages(): Messages | array

Returns the messages generated in the validation.

if (false === $form->isValid($_POST)) {
    $messages = $form->getMessages();
    foreach ($messages as $message) {
        echo $message, "<br>";
    }
}

public function getMessagesFor(string $name): Messages

Returns the messages generated for a specific element

public function getValidation(): ValidationInterface

Returns the validator object registered in the form

public function getUserOption(
    string option, 
    mixed defaultValue = null
): mixed

Returns the value of an option if present. If the option is not present the defaultValue will be returned.

public function getUserOptions(): array

Returns the options for the element

public function getValue(string $name): mixed | null

Gets a value from the internal related entity or from the default value

public function has(string $name): bool

Check if the form contains an element

public function hasMessagesFor(string $name): bool

Check if messages were generated for a specific element

public function isValid(
    array $data = null, 
    object $entity = null
): bool

Validates the form. The first element is the data that has been provided by the user. This is usually the $_POST array.

The second optional parameter is entity (object). If passed, internally the component will call bind() which will: - Loop through the passed data - Check if the element from the data exists (with the same name) in the entity - If yes, check the form's whitelist array. If the element exists there, it will not be changed - The value of the element (from the data array) will be sanitized based on the defined filters (if any) - Call any setters on the entity if present - Assign the value to the property with the same name on the entity.

Once the bind() process finishes, the modified entity will be passed in the beforeValidation event (if events are enabled) and after that all the validators will be called on the form using the modified entity object.

NOTE

Passing an entity object will result in the object being modified by the user input as described above. If you do not wish this behavior, you can clone the entity before passing it, so as to keep a copy of the original object

<?php

use MyApp\Models\Customers;
use Phalcon\Forms\Form;

$customer = Customers::findFirst();
$form = new Form($customer);

if (true === $form->isValid($_POST, $customer)) {
    $customer->save();
}

public function key(): int

Returns the current position/key in the iterator

public function label(
    string $name, 
    array $attributes = null
): string

Generate the label of an element added to the form including HTML. The first parameter is the name of the element while the second one is an array with optional parameters that need to be added to the <label> HTML tag. Such parameter can be CSS classes for instance. If the element is not found in the form, a Phalcon\Forms\Exception will be thrown.

public function next(): void

Moves the internal iteration pointer to the next position

public function render(
    string $name, 
    array attributes = []
): string

Renders a specific item in the form. The optional attributes array parameter can be used to pass additional parameters for the element to be rendered. If the element is not found in the form, a Phalcon\Forms\Exception will be thrown.

public function remove(string $name): bool

Removes an element from the form

public function rewind(): void

Rewinds the internal iterator

public function setAction(string $action): Form

Sets the form's action

public function setEntity(object $entity): Form

Sets the entity related to the model

public function setAttributes(
    Attributes> $attributes
): AttributesInterface

Set form attributes collection

public function setValidation(
    ValidationInterface $validation
);

Sets the validation object in the form.

public function setUserOption(
    string $option, 
    mixed $value
): Form

Sets a user defined option for the form

public function setUserOptions(array $options): Form

Sets user defined options for the form

public function valid(): bool

Returns if the current element in the iterator is valid or not

Initialization¶

Forms can be initialized outside the form class by adding elements to it. However you can reuse code or organize your form classes by implementing forms in their own classes:

<?php

use MyApp\Models\PhoneTypes;
use Phalcon\Forms\Element\Select;
use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Form;

class CustomersForm extends Form
{
    public function initialize()
    {
        $this->add(
            new Text(
                'nameLast'
            )
        );

        $this->add(
            new Text(
                'nameFirst'
            )
        );

        $this->add(
            new Select(
                'phoneType',
                PhoneTypes::find(),
                [
                    'emptyText'  => 'Select one...',
                    'emptyValue' => '',
                    'useEmpty'   => true,
                    'using'      => [
                        'typ_id',
                        'typ_name',
                    ],
                ]
            )
        );
    }
}

We can also pass an array of user defined options in the constructor, that will offer more functionality.

<?php

use MyApp\Models\Customers;
use Phalcon\Forms\Element\Hidden;
use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Form;

class CustomersForm extends Form
{
    public function initialize(
        Customers $customer,
        array $options
    ) {
        $mode = $options['mode'] ?? 'view';
        if ('edit' === $mode) {
            $this->add(
                new Hidden(
                    'id'
                )
            );
        }

        $this->add(
            new Text(
                'nameLast'
            )
        );

        $this->add(
            new Text(
                'nameFirst'
            )
        );
    }
}

In the form's instantiation you will use:

<?php

use MyApp\Models\Customers;

$form = new CustomersForm(
    new Customers(),
    [
        'mode' => 'edit',
    ]
);

The code above will check the options array during the initialize method. The code will check for the mode element in the array and if not present it will default to view. If the mode is edit, we are going to add a Phalcon\Forms\Element\Hidden element with the entity's ID in the form. By using the options array we can create reusable forms and also pass in our form additional data that could be required.

Entities¶

An entity such as a Phalcon\Mvc\Model, a PHP class or even a \stdClass object can be passed to the form in order to set default values, or to assign the values from the form to the object.

<?php

use MyApp\Models\Customers;
use Phalcon\Forms\Form;

$customer = Customers::findFirst();
$form = new Form($customer);

$form->add(
    new Text(
        'nameFirst'
    )
);

$form->add(
    new Text(
        'nameLast'
    )
);

Once the form is rendered if there are no default values assigned to the elements it will use the ones provided by the entity:

<?php echo $form->render('nameLast'); ?>

You can also validate the form and assign the values from the user input to the entity as follows:

<?php

use MyApp\Models\Customers;
use Phalcon\Forms\Form;

$customer = Customers::findFirst();
$form = new Form($customer);

$form->bind($_POST, $customer);

if (true === $form->isValid()) {
    $customer->save();
}

In the above example, we get the first Customer record. We pass that object in our form to populate it with initial values. Following that we call the bind method with the entity and the $_POST array. The form will automatically filter input from the $_POST and assign the input to the entity object (Customers). We can then save the object if the form has passed validation.

We can also use a PHP class as an entity:

<?php

class Preferences
{
    public $timezone = 'Europe/Amsterdam';

    public $receiveEmails = 'No';
}

Using this class as entity, allows the form to take the default values from it:

<?php

$form = new Form(
    new Preferences()
);

$form->add(
    new Select(
        'timezone',
        [
            'America/New_York'  => 'New York',
            'Europe/Amsterdam'  => 'Amsterdam',
            'America/Sao_Paulo' => 'Sao Paulo',
            'Asia/Tokyo'        => 'Tokyo',
        ]
    )
);

$form->add(
    new Select(
        'receiveEmails',
        [
            'Yes' => 'Yes, please!',
            'No'  => 'No, thanks',
        ]
    )
);

Entities can implement getters, which have a higher precedence than public properties. These methods offer more flexibility to generate values:

<?php

class Preferences
{
    public $timezone;

    public $receiveEmails;

    public function getTimezone()
    {
        return 'Europe/Amsterdam';
    }

    public function getReceiveEmails()
    {
        return 'No';
    }
}

For the above entity class, the getReceiveEmails and getTimezone methods will be used instead of the receiveEmails and timezone properties.

Elements¶

Phalcon provides a set of built-in elements to use in your forms, all these elements are located in the Phalcon\Forms\Element namespace:

Name	Description
Phalcon\Forms\Element\Check	Generate `input[type=check]` elements
Phalcon\Forms\Element\Date	Generate `input[type=date]` elements
Phalcon\Forms\Element\Email	Generate `input[type=email]` elements
Phalcon\Forms\Element\File	Generate `input[type=file]` elements
Phalcon\Forms\Element\Hidden	Generate `input[type=hidden]` elements
Phalcon\Forms\Element\Numeric	Generate `input[type=number]` elements
Phalcon\Forms\Element\Password	Generate `input[type=password]` elements
Phalcon\Forms\Element\Radio	Generate `radio` elements
Phalcon\Forms\Element\Select	Generate `select` elements based on choices
Phalcon\Forms\Element\Submit	Generate `input[type=submit]` elements
Phalcon\Forms\Element\Text	Generate `input[type=text]` elements
Phalcon\Forms\Element\TextArea	Generate `textarea` elements

These elements use the Phalcon\Tag component transparently.

NOTE

For more information regarding HTML elements, you can check our Tag document

The Phalcon\Forms\Element\Select supports the useEmpty option to enable the use of a blank element within the list of available options. The options emptyText andemptyValue are optional, which allow you to customize, respectively, the text and the value of the empty element

You can also create your own elements by extending the Phalcon\Forms\Element\ElementInterface interface.

<?php

use Phalcon\Forms\Element;

class MyElement extends Element
{
    public function render($attributes = null)
    {
        $html = '';// HTML

        return $html;
    }
}

Filtering¶

A form is also able to filter data before it is validated. You can set filters in each element:

<?php

use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Form;

$form = new Form();

$name = new Text('nameLast');
$name->setFilters(
    [
        'string',
        'trim',
    ]
);
$form->add($name);

$email = new Text('email');
$email->setFilters(
    'email'
);
$form->add($email);

NOTE

For more information regarding filters, you can check our Filter document

Validation¶

Phalcon forms are integrated with the validation component to offer instant validation. Built-in or custom validators could be set to each element:

<?php

use Phalcon\Forms\Element\Text;
use Phalcon\Validation\Validator\PresenceOf;
use Phalcon\Validation\Validator\StringLength;

$name = new Text(
    'nameLast'
);

$name->addValidator(
    new PresenceOf(
        [
            'message' => 'The name is required',
        ]
    )
);

$name->addValidator(
    new StringLength(
        [
            'min'            => 10,
            'messageMinimum' => 'The name is too short',
        ]
    )
);

$form->add($name);

Then you can validate the form according to the input entered by the user:

<?php

if (false === $form->isValid($_POST)) {
    $messages = $form->getMessages();

    foreach ($messages as $message) {
        echo $message, '<br>';
    }
}

Validators are executed in the same order as they were registered.

By default messages generated by all the elements in the form are joined so they can be traversed using a single foreach. You can also get specific messages for an element:

<?php

$messages = $form->getMessagesFor('nameLast');

foreach ($messages as $message) {
    echo $message, '<br>';
}

Rendering¶

You can render the form with total flexibility, the following example shows how to render each element using a standard procedure:

<form method='post'>
    <?php

        // Traverse the form
        foreach ($form as $element) {
            // Get any generated messages for the current element
            $messages = $form->getMessagesFor(
                $element->getName()
            );

            if (count($messages)) {
                // Print each element
                echo '<div class="messages">';

                foreach ($messages as $message) {
                    echo $message;
                }

                echo '</div>';
            }

            echo '<p>';
            echo '<label for="' . 
                    $element->getName() .
                 '">' .
                 $element->getLabel() .
                 '</label>' 
             ;

            echo $element;
            echo '</p>';
        }
    ?>

    <input type='submit' value='Send' />
</form>

Or reuse the logic in your form class:

<?php

use Phalcon\Forms\Form;

class ContactForm extends Form
{
    public function initialize()
    {
        // ...
    }

    public function renderDecorated($name)
    {
        $element  = $this->get($name);
        $messages = $this->getMessagesFor(
            $element->getName()
        );

        if (count($messages)) {
            echo "<div class='messages'>";

            foreach ($messages as $message) {
                echo $this->flash->error($message);
            }

            echo '</div>';
        }

        echo '<p>';
        echo '<label for="' .
                $element->getName() .
             '">' .
             $element->getLabel() .
             '</label>';

        echo $element;
        echo '</p>';
    }
}

In the view:

<?php

echo $element->renderDecorated('nameLast');
echo $element->renderDecorated('nameFirst');

Events¶

Whenever forms are implemented as classes, the callbacks: beforeValidation() and afterValidation() methods can be implemented in the form's class to perform pre-validations and post-validations:

<?php

use Phalcon\Forms\Form;

class ContactForm extends Form
{
    public function beforeValidation()
    {

    }
}

Manager¶

This component provides the Phalcon\Forms\Manager that can be used by the developer to register forms and access them via the service locator:

<?php

use Phalcon\Di\FactoryDefault;
use Phalcon\Forms\Manager;

$container = new FactoryDefault();
$container->set(
    'forms',
    function () {
        return new Manager();
    }
);

Forms are added to the forms manager and referenced by a unique name:

<?php

$this
    ->forms
    ->set(
        'login',
        new LoginForm()
    )
;

Using the unique name, forms can be accessed in any part of the application:

<?php

$loginForm = $this->forms->get('login');

echo $loginForm->render();

If a form is not found in the manager, a Phalcon\Forms\Exception will be thrown.

Exceptions¶

Any exceptions thrown in the Phalcon\Forms namespace will be Phalcon\Forms\Exception. You can use these exceptions to selectively catch exceptions thrown only from this component.

<?php

use Phalcon\Forms\Exception;
use Phalcon\Forms\Manager;
use Phalcon\Mvc\Controller;

/**
 * @property Manager $forms
 */
class IndexController extends Controller
{
    public function index()
    {
        try {
            $this->forms->get('unknown-form');
        } catch (Exception $ex) {
            echo $ex->getMessage();
        }
    }
}

Dependency Injection¶

Phalcon\Forms\Form extends Phalcon\Di\Injectable so you have access to the application services if needed:

<?php

use Phalcon\Forms\Element\Hidden;
use Phalcon\Forms\Element\Text;
use Phalcon\Forms\Form;
use Phalcon\Security;

/**
 * @property Security $security
 */
class ContactForm extends Form
{
    public function initialize()
    {
        // Set the same form as entity
        $this->setEntity($this);

        // Add a text element to capture the 'email'
        $this->add(
            new Text(
                'email'
            )
        );

        // Add a text element to put a hidden CSRF
        $this->add(
            new Hidden(
                'csrf'
            )
        );
    }

    public function getCsrf()
    {
        return $this->security->getToken();
    }
}

Additional Resources¶

Vökuró, is a sample application that uses the forms builder to create and manage forms, [GitHub]