# Class yii\helpers\BaseUrl

Inheritance | yii\helpers\BaseUrl
Subclasses | yii\helpers\Url
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/helpers/BaseUrl.php

BaseUrl provides concrete implementation for yii\helpers\Url.

Do not use BaseUrl. Use yii\helpers\Url instead.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$urlManager | yii\web\UrlManager | URL manager to use for creating URLs | yii\helpers\BaseUrl

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
base() | Returns the base URL of the current request. | yii\helpers\BaseUrl
canonical() | Returns the canonical URL of the currently requested page. | yii\helpers\BaseUrl
current() | Creates a URL by using the current route and the GET parameters. | yii\helpers\BaseUrl
ensureScheme() | Normalize URL by ensuring that it use specified scheme. | yii\helpers\BaseUrl
home() | Returns the home URL. | yii\helpers\BaseUrl
isRelative() | Returns a value indicating whether a URL is relative. | yii\helpers\BaseUrl
previous() | Returns the URL previously remembered. | yii\helpers\BaseUrl
remember() | Remembers the specified URL so that it can be later fetched back by previous(). | yii\helpers\BaseUrl
to() | Creates a URL based on the given parameters. | yii\helpers\BaseUrl
toRoute() | Creates a URL for the given route. | yii\helpers\BaseUrl

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
getUrlManager() |  | yii\helpers\BaseUrl
normalizeRoute() | Normalizes route and makes it suitable for UrlManager. Absolute routes are staying as is while relative routes are converted to absolute ones. | yii\helpers\BaseUrl

## Property Details

$urlManager public static property (available since version 2.0.8)

URL manager to use for creating URLs

public static yii\web\UrlManager $urlManager = null

## Method Details

base() public static method

Returns the base URL of the current request.

public static string base ( $scheme = false )

$scheme

boolean|string

The URI scheme to use in the returned base URL:

- `false` (default): returning the base URL without host info.
- `true`: returning an absolute base URL whose scheme is the same as that in yii\web\UrlManager::$hostInfo.
- string: returning an absolute base URL with the specified scheme (either `http`, `https` or empty string for protocol-relative URL).

canonical() public static method

Returns the canonical URL of the currently requested page.

The canonical URL is constructed using the current controller's yii\web\Controller::$route and yii\web\Controller::$actionParams. You may use the following code in the layout view to add a link tag about canonical URL:

    $this->registerLinkTag(['rel' => 'canonical', 'href' => Url::canonical()]);

public static string canonical ( )
return | string | The canonical URL of the currently requested page

current() public static method (available since version 2.0.3)

Creates a URL by using the current route and the GET parameters.

You may modify or remove some of the GET parameters, or add additional query parameters through the `$params` parameter. In particular, if you specify a parameter to be null, then this parameter will be removed from the existing GET parameters; all other parameters specified in `$params` will be merged with the existing GET parameters. For example,

    // assume $_GET = ['id' => 123, 'src' => 'google'], current route is "post/view"

    // /index.php?r=post%2Fview&id=123&src=google
    echo Url::current();

    // /index.php?r=post%2Fview&id=123
    echo Url::current(['src' => null]);

    // /index.php?r=post%2Fview&id=100&src=google
    echo Url::current(['id' => 100]);

Note that if you're replacing array parameters with `[]` at the end you should specify `$params` as nested arrays. For a `PostSearchForm` model where parameter names are `PostSearchForm[id]` and `PostSearchForm[src]` the syntax would be the following:

    // index.php?r=post%2Findex&PostSearchForm%5Bid%5D=100&PostSearchForm%5Bsrc%5D=google
    echo Url::current([
        $postSearch->formName() => ['id' => 100, 'src' => 'google'],
    ]);

public static string current ( array $params = [], $scheme = false )
$params | array | An associative array of parameters that will be merged with the current GET parameters. If a parameter value is null, the corresponding GET parameter will be removed.

$scheme

boolean|string

The URI scheme to use in the generated URL:

- `false` (default): generating a relative URL.
- `true`: returning an absolute base URL whose scheme is the same as that in yii\web\UrlManager::$hostInfo.
- string: generating an absolute URL with the specified scheme (either `http`, `https` or empty string for protocol-relative URL).

return | string | The generated URL

ensureScheme() public static method (available since version 2.0.11)

Normalize URL by ensuring that it use specified scheme.

If URL is relative or scheme is not string, normalization is skipped.

public static string ensureScheme ( $url, $scheme )
$url | string | The URL to process
$scheme | string | The URI scheme used in URL (e.g. `http` or `https`). Use empty string to create protocol-relative URL (e.g. `//example.com/path`)
return | string | The processed URL

getUrlManager() protected static method (available since version 2.0.8)

protected static yii\web\UrlManager getUrlManager ( )
return | yii\web\UrlManager | URL manager used to create URLs

home() public static method

Returns the home URL.

public static string home ( $scheme = false )

$scheme

boolean|string

The URI scheme to use for the returned URL:

- `false` (default): returning a relative URL.
- `true`: returning an absolute base URL whose scheme is the same as that in yii\web\UrlManager::$hostInfo.
- string: returning an absolute URL with the specified scheme (either `http`, `https` or empty string for protocol-relative URL).

return | string | Home URL

isRelative() public static method

Returns a value indicating whether a URL is relative.

A relative URL does not have host info part.

public static boolean isRelative ( $url )
$url | string | The URL to be checked
return | boolean | Whether the URL is relative

normalizeRoute() protected static method

Normalizes route and makes it suitable for UrlManager. Absolute routes are staying as is while relative routes are converted to absolute ones.

A relative route is a route without a leading slash, such as "view", "post/view".

- If the route is an empty string, the current route will be used;
- If the route contains no slashes at all, it is considered to be an action ID of the current controller and will be prepended with yii\web\Controller::$uniqueId;
- If the route has no leading slash, it is considered to be a route relative to the current module and will be prepended with the module's uniqueId.

Starting from version 2.0.2, a route can also be specified as an alias. In this case, the alias will be converted into the actual route first before conducting the above transformation steps.

protected static string normalizeRoute ( $route )
$route | string | The route. This can be either an absolute route or a relative route.
return | string | Normalized route suitable for UrlManager
throws | yii\base\InvalidArgumentException | a relative route is given while there is no active controller

previous() public static method

Returns the URL previously remembered.

See also:

- remember()
- yii\web\User::getReturnUrl()

public static string|null previous ( $name = null )
$name | string | The named associated with the URL that was remembered previously. If not set, yii\web\User::getReturnUrl() will be used to obtain remembered URL.
return | string|null | The URL previously remembered. Null is returned if no URL was remembered with the given name and `$name` is not specified.

remember() public static method

Remembers the specified URL so that it can be later fetched back by previous().

See also:

- previous()
- yii\web\User::setReturnUrl()

public static void remember ( $url = '', $name = null )
$url | string|array | The URL to remember. Please refer to to() for acceptable formats. If this parameter is not specified, the currently requested URL will be used.
$name | string | The name associated with the URL to be remembered. This can be used later by previous(). If not set, yii\web\User::setReturnUrl() will be used with passed URL.

to() public static method

Creates a URL based on the given parameters.

This method is very similar to toRoute(). The only difference is that this method requires a route to be specified as an array only. If a string is given, it will be treated as a URL. In particular, if `$url` is

- an array: toRoute() will be called to generate the URL. For example: `['site/index']`, `['post/index', 'page' => 2]`. Please refer to toRoute() for more details on how to specify a route.
- a string with a leading `@`: it is treated as an alias, and the corresponding aliased string will be returned.
- an empty string: the currently requested URL will be returned;
- a normal string: it will be returned as is.

When `$scheme` is specified (either a string or `true`), an absolute URL with host info (obtained from yii\web\UrlManager::$hostInfo) will be returned. If `$url` is already an absolute URL, its scheme will be replaced with the specified one.

Below are some examples of using this method:

    // /index.php?r=site%2Findex
    echo Url::to(['site/index']);

    // /index.php?r=site%2Findex&src=ref1#name
    echo Url::to(['site/index', 'src' => 'ref1', '#' => 'name']);

    // /index.php?r=post%2Findex     assume the alias "@posts" is defined as "/post/index"
    echo Url::to(['@posts']);

    // the currently requested URL
    echo Url::to();

    // /images/logo.gif
    echo Url::to('@web/images/logo.gif');

    // images/logo.gif
    echo Url::to('images/logo.gif');

    // http://www.example.com/images/logo.gif
    echo Url::to('@web/images/logo.gif', true);

    // https://www.example.com/images/logo.gif
    echo Url::to('@web/images/logo.gif', 'https');

    // //www.example.com/images/logo.gif
    echo Url::to('@web/images/logo.gif', '');

public static string to ( $url = '', $scheme = false )
$url | array|string | The parameter to be used to generate a valid URL

$scheme

boolean|string

The URI scheme to use in the generated URL:

- `false` (default): generating a relative URL.
- `true`: returning an absolute base URL whose scheme is the same as that in yii\web\UrlManager::$hostInfo.
- string: generating an absolute URL with the specified scheme (either `http`, `https` or empty string for protocol-relative URL).

return | string | The generated URL
throws | yii\base\InvalidArgumentException | a relative route is given while there is no active controller

toRoute() public static method

Creates a URL for the given route.

This method will use yii\web\UrlManager to create a URL.

You may specify the route as a string, e.g., `site/index`. You may also use an array if you want to specify additional query parameters for the URL being created. The array format must be:

    // generates: /index.php?r=site/index&param1=value1&param2=value2
    ['site/index', 'param1' => 'value1', 'param2' => 'value2']

If you want to create a URL with an anchor, you can use the array format with a `#` parameter. For example,

    // generates: /index.php?r=site/index&param1=value1#name
    ['site/index', 'param1' => 'value1', '#' => 'name']

A route may be either absolute or relative. An absolute route has a leading slash (e.g. `/site/index`), while a relative route has none (e.g. `site/index` or `index`). A relative route will be converted into an absolute one by the following rules:

- If the route is an empty string, the current route will be used;
- If the route contains no slashes at all (e.g. `index`), it is considered to be an action ID of the current controller and will be prepended with yii\web\Controller::$uniqueId;
- If the route has no leading slash (e.g. `site/index`), it is considered to be a route relative to the current module and will be prepended with the module's uniqueId.

Starting from version 2.0.2, a route can also be specified as an alias. In this case, the alias will be converted into the actual route first before conducting the above transformation steps.

Below are some examples of using this method:

    // /index.php?r=site%2Findex
    echo Url::toRoute('site/index');

    // /index.php?r=site%2Findex&src=ref1#name
    echo Url::toRoute(['site/index', 'src' => 'ref1', '#' => 'name']);

    // http://www.example.com/index.php?r=site%2Findex
    echo Url::toRoute('site/index', true);

    // https://www.example.com/index.php?r=site%2Findex
    echo Url::toRoute('site/index', 'https');

    // /index.php?r=post%2Findex     assume the alias "@posts" is defined as "post/index"
    echo Url::toRoute('@posts');

public static string toRoute ( $route, $scheme = false )
$route | string|array | Use a string to represent a route (e.g. `index`, `site/index`), or an array to represent a route with query parameters (e.g. `['site/index', 'param1' => 'value1']`).

$scheme

boolean|string

The URI scheme to use in the generated URL:

- `false` (default): generating a relative URL.
- `true`: returning an absolute base URL whose scheme is the same as that in yii\web\UrlManager::$hostInfo.
- string: generating an absolute URL with the specified scheme (either `http`, `https` or empty string for protocol-relative URL).

return | string | The generated URL
throws | yii\base\InvalidArgumentException | a relative route is given while there is no active controller