HTML Link (PSR-13)¶

Overview¶

Phalcon\Html\Link\EvolvableLink, Phalcon\Html\Link\EvolvableLinkProvider, Phalcon\Html\Link\Link and Phalcon\Html\Link\LinkProvider are classes that implement the interfaces as defined by PHP-FIG.

These components aid in creating Link objects as defined by the PSR-13 standard.

NOTE

This component does not generate any HTML links. It just stores the links and offers methods as defined by the PSR-13 standard. You will need to create your own serializers that will parse these objects and generate the necessary output. The Phalcon\Html\Link\Serializer\Header serializer is available for you to use.

Link¶

The Phalcon\Html\Link\Link is used to create a link and assign attributes to it upon construction.

<?php

use Phalcon\Html\Link\Link;

$href       = 'https://dev.phalcon.ld';
$attributes = [
    'one'   => true,
    'two'   => 123,
    'three' => 'four',
    'five'  => [
        'six',
        'seven',
    ],
];

$link = new Link('payment', $href, $attributes);

LinkProvider¶

The Phalcon\Html\Link\LinkProvider is used as a container of Phalcon\Html\Link\Link objects. You can add them in the provider and then access them as a whole or retrieve them by rel.

<?php

use Phalcon\Html\Link\Link;
use Phalcon\Html\Link\LinkProvider;

$links = [
    new Link('canonical', 'https://dev.phalcon.ld'),
    new Link('cite-as', 'https://test.phalcon.ld'),
];
$link  = new LinkProvider($links);


var_dump(
    $link->getLinksByRel('cite-as')
);

// [
//     Link('cite-as', 'https://test.phalcon.ld'),
// ]

EvolvableLink¶

Link objects are immutable. However, there is a need to manipulate them based on your application needs. The Phalcon\Html\Link\EvolvableLink is available, allowing you to manipulate the link.

<?php

use Phalcon\Html\Link\EvolvableLink;

$href       = 'https://dev.phalcon.ld';
$attributes = ['one' => true];

$link = new EvolvableLink('payment', $href, $attributes);

$newInstance = $link->withAttribute('two', 'three');

var_dump(
    $newInstance->getAttributes()
);

//  [
//      'one' => true,
//      'two' => 'three',
//  ];

EvolvableLinkProvider¶

The Phalcon\Html\Link\LinkProvider is used as a container of Phalcon\Html\Link\EvolvableLink objects. You can add them in the provider and then access them as a whole or retrieve them by rel.

<?php

use Phalcon\Html\Link\EvolvableLink;
use Phalcon\Html\Link\EvolvableLinkProvider;

$links = [
    new Link('canonical', 'https://dev.phalcon.ld'),
    new Link('cite-as', 'https://test.phalcon.ld'),
];
$link  = new EvolvableLinkProvider($links);


var_dump(
    $link->getLinksByRel('cite-as')
);

// [
//     Link('cite-as', 'https://test.phalcon.ld'),
// ]

Serializers¶

You can use a serializer to parse the Phalcon\Html\Links objects and create the necessary headers. Phalcon comes with the Phalcon\Html\Link\Serializer\Header serializer, to help with the task of serializing links for the headers:

<?php

use Phalcon\Html\Link\EvolvableLink;
use Phalcon\Html\Link\Serializer\Header;

$serializer = new Header();

$link = new EvolvableLink('prefetch', '/images/apple-icon-114.png');

echo $serializer->serialize([$link]);
// </images/apple-icon-114.png>; rel="prefetch"';


$links = [
    (new EvolvableLink('preload', '/1'))
        ->withAttribute('as', 'image')
        ->withAttribute('nopush', true),
    (new EvolvableLink('alternate', '/2'))
        ->withRel('next')
        ->withAttribute('hreflang', ['en', 'es'])
];

echo $serializer->serialize([$link]);
// </1>; rel="preload"; as="image"; nopush,
//     </2>; rel="alternate next"; hreflang="en"; hreflang="es"
;

Custom¶

You can create your own serializers for relevant links by extending the Phalcon\Html\Link\Serializer\SerializerInterface

<?php

namespace MyApp\Html\Serializers;

use Phalcon\Html\Link\Serializer\SerializerInterface;

class Custom implements SerializerInterface 
{
    public function serialize(array $links): ?string
    {
        // ....
    }
}