Please consider using the the latest stable version for any production code.

URI Template

League\Uri\UriTemplate is available since version 6.1.0

The League\Uri\UriTemplate class enables expanding a URI object based on a URI template and its submitted parameters following RFC 6570 URI Template.

The parser is RFC6570 compliant

Don’t feel like reading RFC 6570? Here are a quick refresher to understand its rules:

template are made of expressions consisting of an operator and a variable specification;
a variable specification consists at least of one variable name and an optional modifier;
the RFC defines 4 levels of interpolation and all 4 are supported by the given class.

The UriTemplate::expand public method provides the mean for expanding a URI template to generate a valid URI conforming to RFC3986 if given a supplied set of data.

<?php

use League\Uri\UriTemplate;

$template = 'https://example.com/hotels/{hotel}/bookings/{booking}';
$params = ['booking' => '42', 'hotel' => 'Rest & Relax'];

$uriTemplate = new UriTemplate($template);
$uri = $uriTemplate->expand($params);
// $uri is an League\Uri\Uri instance.

echo $uri, PHP_EOL;
// https://example.com/hotels/Rest%20%26%20Relax/bookings/42

Variables

For maximum interoperability you should make sure your variables are strings or objects that expose the __toString method otherwise the value will be cast to string following PHP rules except for boolean values true and false which will be converted to 1 and 0 respectively.

Default variables can be set using the constructor

The constructor takes a optional set of default variables that can be applied by default when expanding the URI template.

<?php

use League\Uri\UriTemplate;
$template = 'https://api.twitter.com/{version}/search/{term:1}/{term}/{?q*,limit}';

$params = [
    'term' => 'john',
    'q' => ['a', 'b'],
    'limit' => '10',
];

$uriTemplate = new UriTemplate($template, ['version' => 1.1]);
echo $uriTemplate->expand($params), PHP_EOL;
// https://api.twitter.com/1.1/search/j/john/?q=a&q=b&limit=10

Applying variables with the expand method

The default variables are overwritten by those supplied to the expand method.

<?php

use League\Uri\UriTemplate;
$template = 'https://api.twitter.com/{version}/search/{term:1}/{term}/{?q*,limit}';

$params = [
    'term' => 'john',
    'q' => ['a', 'b'],
    'limit' => '10',
    'version' => '2.0'
];

$uriTemplate = new UriTemplate($template, ['version' => '1.1']);
echo $uriTemplate->expand($params), PHP_EOL;
// https://api.twitter.com/2.0/search/j/john/?q=a&q=b&limit=10

Updating the default variables

At any given time you may update your default variables but since the UriTemplate is an immutable object instead of modifying the current instance, a new instance with the modified default variables will be returned.

<?php

use League\Uri\UriTemplate;
$template = 'https://api.twitter.com/{version}/search/{term:1}/{term}/{?q*,limit}';

$params = [
    'term' => 'john',
    'q' => ['a', 'b'],
    'limit' => '10',
    'version' => '2.0'
];

$uriTemplate = new UriTemplate($template, ['version' => '1.0', 'foo' => 'bar']);
$uriTemplate->getDefaultVariables(); //returns ['version' => '1.0']
$newUriTemplate = $uriTemplate->withDefaultVariables(['version' => '1.1']);
$newUriTemplate->getDefaultVariables(); //returns  ['version' => '1.1']

Nested array are disallowed

This class follows only the RFC6570 requirements and thus, does not support nested array like the one used with http_build_query

<?php

use League\Uri\UriTemplate;

$template = 'https://example.com/hotels/{hotel}/book{?query*}';
$params = [
    'hotel' => 'Rest & Relax',
    'query' => [
        'period' => [
            'start' => '2020-01-12',
            'end' => '2020-01-15',
        ],
    ],
];

$uriTemplate = new UriTemplate($template);
$uriTemplate->expand($params);
// will throw a League\Uri\Exceptions\TemplateCanNotBeExpanded when trying to expand the `period` value.

Using the prefix modifier on a list will trigger an exception.

While this is not forbidden by the RFC, the UriTemplate class will throw an exception if an attempt is made to use the prefix modifier with a list of value. Other implementations will silently ignore the modifier but this package will trigger the exception to alert the user that something might be wrong and that the generated URI might not be the one expected.

<?php

use League\Uri\UriTemplate;
$template = 'https://api.twitter.com/{version}/search/{term:1}/{term}/{?q*,limit}';

$params = [
    'term' => ['john', 'doe'],
    'q' => ['a', 'b'],
    'limit' => '10',
    'version' => '2.0'
];

$uriTemplate = new UriTemplate($template);
echo $uriTemplate->expand($params), PHP_EOL;
// throw a League\Uri\Exceptions\TemplateCanNotBeExpanded because the term variable is a list and not a string.

Expressions

Using braces in your template

The following implementation disallow the use of braces { or } outside of being URI template expression delimiters. If found outside of an expression an exception will be triggered.

<?php

use League\Uri\UriTemplate;

$template = 'https://example.com/hotels/{/book{?query*}';
$uriTemplate = new UriTemplate($template);
// will throw a League\Uri\Exceptions\SyntaxError on instantiation

If your template do require them you should URL encode them.

<?php

use League\Uri\UriTemplate;

$template = 'https://example.com/hotels/%7B/{hotel}';
$params = ['booking' => 42, 'hotel' => 'Rest & Relax'];

$uriTemplate = new UriTemplate($template);
echo $uriTemplate->expand($params), PHP_EOL;
// https://example.com/hotels/%7B/Rest%20%26%20Relax