silverstripe-framework/dev/Deprecation.php

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<?php
/**
* Handles raising an notice when accessing a deprecated method
*
* A pattern used in SilverStripe when deprecating a method is to add something like
* user_error('This method is deprecated', E_USER_NOTICE);
* to the method
*
* However sometimes we want to mark that a method will be deprecated in some future version and shouldn't be used in
* new code, but not forbid in the current version - for instance when that method is still heavily used in framework
* or cms.
*
* This class abstracts the above pattern and adds a way to do that.
*
* Each call to notice passes a version that the notice will be valid from. Additionally this class has a notion of the
* version it should use when deciding whether to raise the notice. If that version is equal to or greater than the
* notices version (and SilverStripe is in dev mode) a deprecation message will be raised.
*
* Normally the checking version will be the release version of SilverStripe, but a developer can choose to set it to a
* future version, to see how their code will behave in future versions.
*
* Modules can also set the version for calls they make - either setting it to a future version in order to ensure
* forwards compatibility or setting it backwards if a module has not yet removed references to deprecated methods.
*
* When set per-module, only direct calls to deprecated methods from those modules are considered - if the module
* calls a non-module method which then calls a deprecated method, that call will use the global check version, not
* the module specific check version.
*
* @package framework
* @subpackage dev
*/
class Deprecation {
const SCOPE_METHOD = 1;
const SCOPE_CLASS = 2;
const SCOPE_GLOBAL = 4;
/**
*
* @var string
*/
protected static $version;
/**
* Override whether deprecation is enabled. If null, then fallback to
* SS_DEPRECATION_ENABLED, and then true if not defined.
*
* Deprecation is only available on dev.
*
* Must be configured outside of the config API, as deprecation API
* must be available before this to avoid infinite loops.
*
* @var boolean|null
*/
protected static $enabled = null;
/**
*
* @var array
*/
protected static $module_version_overrides = array();
/**
* @var int - the notice level to raise on a deprecation notice. Defaults to E_USER_DEPRECATED if that exists,
* E_USER_NOTICE if not
*/
public static $notice_level = null;
/**
* Set the version that is used to check against the version passed to notice. If the ::notice version is
* greater than or equal to this version, a message will be raised
*
* @static
* @param $ver string -
* A php standard version string, see http://php.net/manual/en/function.version-compare.php for details.
* @param null $forModule string -
* The name of a module. The passed version will be used as the check value for
* calls directly from this module rather than the global value
* @return void
*/
public static function notification_version($ver, $forModule = null) {
if ($forModule) {
self::$module_version_overrides[$forModule] = $ver;
}
else {
self::$version = $ver;
}
}
/**
* Given a backtrace, get the module name from the caller two removed (the caller of the method that called
* #notice)
*
* @static
* @param $backtrace array - a backtrace as returned from debug_backtrace
* @return string - the name of the module the call came from, or null if we can't determine
*/
protected static function get_calling_module_from_trace($backtrace) {
if (!isset($backtrace[1]['file'])) return;
$callingfile = realpath($backtrace[1]['file']);
$manifest = SS_ClassLoader::instance()->getManifest();
foreach ($manifest->getModules() as $name => $path) {
if (strpos($callingfile, realpath($path)) === 0) {
return $name;
}
}
}
/**
* Given a backtrace, get the method name from the immediate parent caller (the caller of #notice)
*
* @static
* @param $backtrace array - a backtrace as returned from debug_backtrace
* @param $level - 1 (default) will return immediate caller, 2 will return caller's caller, etc.
* @return string - the name of the method
*/
protected static function get_called_method_from_trace($backtrace, $level = 1) {
$level = (int)$level;
if(!$level) $level = 1;
$called = $backtrace[$level];
if (isset($called['class'])) {
return $called['class'] . $called['type'] . $called['function'];
}
else {
return $called['function'];
}
}
/**
* Determine if deprecation notices should be displayed
*
* @return bool
*/
public static function get_enabled() {
// Deprecation is only available on dev
if(!Director::isDev()) {
return false;
}
if(isset(self::$enabled)) {
return self::$enabled;
}
if(defined('SS_DEPRECATION_ENABLED')) {
return SS_DEPRECATION_ENABLED;
}
return true;
}
/**
* Toggle on or off deprecation notices. Will be ignored in live.
*
* @param bool $enabled
*/
public static function set_enabled($enabled) {
self::$enabled = $enabled;
}
/**
* Raise a notice indicating the method is deprecated if the version passed as the second argument is greater
* than or equal to the check version set via ::notification_version
*
* @param string $atVersion The version at which this notice should start being raised
* @param string $string The notice to raise
* @param bool $scope Notice relates to the method or class context its called in.
*/
public static function notice($atVersion, $string = '', $scope = Deprecation::SCOPE_METHOD) {
if(!static::get_enabled()) {
return;
}
$checkVersion = self::$version;
// Getting a backtrace is slow, so we only do it if we need it
$backtrace = null;
// If you pass #.#, assume #.#.0
if(preg_match('/^[0-9]+\.[0-9]+$/', $atVersion)) $atVersion .= '.0';
if(preg_match('/^[0-9]+\.[0-9]+$/', $checkVersion)) $checkVersion .= '.0';
if(self::$module_version_overrides) {
$module = self::get_calling_module_from_trace($backtrace = debug_backtrace(0));
if(isset(self::$module_version_overrides[$module])) {
$checkVersion = self::$module_version_overrides[$module];
}
}
// Check the version against the notice version
if ($checkVersion && version_compare($checkVersion, $atVersion, '>=')) {
// Get the calling scope
if($scope == Deprecation::SCOPE_METHOD) {
if (!$backtrace) $backtrace = debug_backtrace(0);
$caller = self::get_called_method_from_trace($backtrace);
} elseif($scope == Deprecation::SCOPE_CLASS) {
if (!$backtrace) $backtrace = debug_backtrace(0);
$caller = isset($backtrace[1]['class']) ? $backtrace[1]['class'] : '(unknown)';
} else {
$caller = false;
}
// Get the level to raise the notice as
$level = self::$notice_level;
if (!$level) $level = E_USER_DEPRECATED;
// Then raise the notice
if(substr($string,-1) != '.') $string .= ".";
$string .= " Called from " . self::get_called_method_from_trace($backtrace, 2) . '.';
if($caller) {
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user_error($caller.' is deprecated.'.($string ? ' '.$string : ''), $level);
} else {
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user_error($string, $level);
}
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}
}
/**
* Method for when testing. Dump all the current version settings to a variable for later passing to restore
*
* @return array Opaque array that should only be used to pass to {@see Deprecation::restore_settings()}
*/
public static function dump_settings() {
return array(
'level' => self::$notice_level,
'version' => self::$version,
'moduleVersions' => self::$module_version_overrides,
'enabled' => self::$enabled,
);
}
/**
* Method for when testing. Restore all the current version settings from a variable
*
* @param $settings array An array as returned by {@see Deprecation::dump_settings()}
*/
public static function restore_settings($settings) {
self::$notice_level = $settings['level'];
self::$version = $settings['version'];
self::$module_version_overrides = $settings['moduleVersions'];
self::$enabled = $settings['enabled'];
}
}