Constants & Functions

While most of your day-to-day work in CakePHP will be utilizing core classes andmethods, CakePHP features a number of global convenience functions that may comein handy. Many of these functions are for use with CakePHP classes (loadingmodel or component classes), but many others make working with arrays orstrings a little easier.

We’ll also cover some of the constants available in CakePHP applications. Usingthese constants will help make upgrades more smooth, but are also convenientways to point to certain files or directories in your CakePHP application.

Global Functions

Here are CakePHP’s globally available functions. Most of them are justconvenience wrappers for other CakePHP functionality, such as debugging andtranslating content.

  • (string $string_id[, $formatArgs])[](https://book.cakephp.org/4/en/core-libraries/#)
  • This function handles localization in CakePHP applications. The$string_id identifies the ID for a translation. You can supplyadditional arguments to replace placeholders in your string:
  1. __('You have {0} unread messages', $number);

You can also provide a name-indexed array of replacements:

  1. __('You have {unread} unread messages', ['unread' => $number]);

Note

Check out theInternationalization & Localization section formore information.

Useful when internationalizing a plugin:echo __d('PluginName', 'This is my plugin');

  • dn(string $domain, string $singular, string $plural, integer $count, mixed $args = null)[](https://book.cakephp.org/4/en/core-libraries/#dn)
  • Allows you to override the current domain for a single plural messagelookup. Returns correct plural form of message identified by $singularand $plural for count $count from domain $domain.
  • dx(string $domain, string $context, string $msg, mixed $args = null)[](https://book.cakephp.org/4/en/core-libraries/#dx)
  • Allows you to override the current domain for a single message lookup. Italso allows you to specify a context.

The context is a unique identifier for the translations string that makes itunique within the same domain.

  • dxn(string $domain, string $context, string $singular, string $plural, integer $count, mixed $args = null)[](https://book.cakephp.org/4/en/core-libraries/#dxn)
  • Allows you to override the current domain for a single plural messagelookup. It also allows you to specify a context. Returns correct pluralform of message identified by $singular and $plural for count$count from domain $domain. Some languages have more than one formfor plural messages dependent on the count.

The context is a unique identifier for the translations string that makes itunique within the same domain.

  • n(string $singular, string $plural, integer $count, mixed $args = null)[](https://book.cakephp.org/4/en/core-libraries/#n)
  • Returns correct plural form of message identified by $singular and$plural for count $count. Some languages have more than one form forplural messages dependent on the count.
  • xn(string $context, string $singular, string $plural, integer $count, mixed $args = null)[](https://book.cakephp.org/4/en/core-libraries/#xn)
  • Returns correct plural form of message identified by $singular and$plural for count $count from domain $domain. It also allows youto specify a context. Some languages have more than one form for pluralmessages dependent on the count.

The context is a unique identifier for the translations string that makes itunique within the same domain.

  • collection(mixed $items)
  • Convenience wrapper for instantiating a new Cake\Collection\Collectionobject, wrapping the passed argument. The $items parameter takes eithera Traversable object or an array.
  • debug(mixed $var, boolean $showHtml = null, $showFrom = true)
  • If the core $debug variable is true, $var is printed out.If $showHTML is true or left as null, the data is rendered to bebrowser-friendly. If $showFrom is not set to false, the debug outputwill start with the line from which it was called. Also seeDebugging
  • dd(mixed $var, boolean $showHtml = null)
  • It behaves like debug(), but execution is also halted.If the core $debug variable is true, $var is printed.If $showHTML is true or left as null, the data is rendered to bebrowser-friendly. Also see Debugging
  • pr(mixed $var)
  • Convenience wrapper for print_r(), with the addition ofwrapping <pre> tags around the output.
  • pj(mixed $var)
  • JSON pretty print convenience function, with the addition ofwrapping <pre> tags around the output.

It is meant for debugging the JSON representation of objects and arrays.

  • env(string $key, string $default = null)
  • Gets an environment variable from available sources. Used as a backup if$_SERVER or $_ENV are disabled.

This function also emulates PHP_SELF and DOCUMENT_ROOT onunsupporting servers. In fact, it’s a good idea to always use env()instead of $_SERVER or getenv() (especially if you plan todistribute the code), since it’s a full emulation wrapper.

  • h(string $text, boolean $double = true, string $charset = null)
  • Convenience wrapper for htmlspecialchars().
  • pluginSplit(string $name, boolean $dotAppend = false, string $plugin = null)
  • Splits a dot syntax plugin name into its plugin and class name. If $namedoes not have a dot, then index 0 will be null.

Commonly used like list($plugin, $name) = pluginSplit('Users.User');

  • namespaceSplit(string $class)
  • Split the namespace from the classname.

Commonly used like list($namespace, $className) = namespaceSplit('Cake\Core\App');

Core Definition Constants

Most of the following constants refer to paths in your application.

  • constant APP
  • Absolute path to your application directory, including a trailing slash.
  • constant APP_DIR
  • Equals app or the name of your application directory.
  • constant CACHE
  • Path to the cache files directory. It can be shared between hosts in amulti-server setup.
  • constant CAKE
  • Path to the cake directory.
  • constant CAKE_CORE_INCLUDE_PATH
  • Path to the root lib directory.
  • constant CONFIG
  • Path to the config directory.
  • constant CORE_PATH
  • Path to the CakePHP directory with ending directory slash.
  • constant DS
  • Short for PHP’s DIRECTORY_SEPARATOR, which is / on Linux and \on Windows.
  • constant LOGS
  • Path to the logs directory.
  • constant ROOT
  • Path to the root directory.
  • constant TESTS
  • Path to the tests directory.
  • constant TMP
  • Path to the temporary files directory.
  • constant WWW_ROOT
  • Full path to the webroot.

Timing Definition Constants

  • constant TIME_START
  • Unix timestamp in microseconds as a float from when the application started.
  • constant SECOND
  • Equals 1
  • constant MINUTE
  • Equals 60
  • constant HOUR
  • Equals 3600
  • constant DAY
  • Equals 86400
  • constant WEEK
  • Equals 604800
  • constant MONTH
  • Equals 2592000
  • constant YEAR
  • Equals 31536000