HTML Link¶

Overview¶

Phalcon\Html\Link\EvolvableLink, Phalcon\Html\Link\EvolvableLinkProvider, Phalcon\Html\Link\Link and Phalcon\Html\Link\LinkProvider are classes that implement the interfaces based on PSR-13, but with much stricter types

NOTE

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

Operations¶

The Phalcon\Html\Link\* components implement methods that are in line with PSR-13, but do not implement the particular interface. A package that implements PSR-13 is available, that uses the Phalcon\Html\Link\* components. The package is located here. To use it, you will need to have Phalcon installed and then using composer you can install the proxy package.

composer require phalcon/proxy-psr13

Using the proxy classes allows you to follow PSR-13 and use it with any other package that needs that interface.

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\Link\* 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 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
    {
        // ....
    }
}