Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Component\Utility;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides helpers to perform operations on nested arrays and array keys of variable depth.
Chris@0:  *
Chris@0:  * @ingroup utility
Chris@0:  */
Chris@0: class NestedArray {
Chris@0: 
Chris@0:   /**
Chris@0:    * Retrieves a value from a nested array with variable depth.
Chris@0:    *
Chris@0:    * This helper function should be used when the depth of the array element
Chris@0:    * being retrieved may vary (that is, the number of parent keys is variable).
Chris@0:    * It is primarily used for form structures and renderable arrays.
Chris@0:    *
Chris@0:    * Without this helper function the only way to get a nested array value with
Chris@0:    * variable depth in one line would be using eval(), which should be avoided:
Chris@0:    * @code
Chris@0:    * // Do not do this! Avoid eval().
Chris@0:    * // May also throw a PHP notice, if the variable array keys do not exist.
Chris@0:    * eval('$value = $array[\'' . implode("']['", $parents) . "'];");
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * Instead, use this helper function:
Chris@0:    * @code
Chris@0:    * $value = NestedArray::getValue($form, $parents);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * A return value of NULL is ambiguous, and can mean either that the requested
Chris@0:    * key does not exist, or that the actual value is NULL. If it is required to
Chris@0:    * know whether the nested array key actually exists, pass a third argument
Chris@0:    * that is altered by reference:
Chris@0:    * @code
Chris@0:    * $key_exists = NULL;
Chris@0:    * $value = NestedArray::getValue($form, $parents, $key_exists);
Chris@0:    * if ($key_exists) {
Chris@0:    *   // Do something with $value.
Chris@0:    * }
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * However if the number of array parent keys is static, the value should
Chris@0:    * always be retrieved directly rather than calling this function.
Chris@0:    * For instance:
Chris@0:    * @code
Chris@0:    * $value = $form['signature_settings']['signature'];
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * @param array $array
Chris@0:    *   The array from which to get the value.
Chris@0:    * @param array $parents
Chris@0:    *   An array of parent keys of the value, starting with the outermost key.
Chris@0:    * @param bool $key_exists
Chris@0:    *   (optional) If given, an already defined variable that is altered by
Chris@0:    *   reference.
Chris@0:    *
Chris@0:    * @return mixed
Chris@0:    *   The requested nested value. Possibly NULL if the value is NULL or not all
Chris@0:    *   nested parent keys exist. $key_exists is altered by reference and is a
Chris@0:    *   Boolean that indicates whether all nested parent keys exist (TRUE) or not
Chris@0:    *   (FALSE). This allows to distinguish between the two possibilities when
Chris@0:    *   NULL is returned.
Chris@0:    *
Chris@0:    * @see NestedArray::setValue()
Chris@0:    * @see NestedArray::unsetValue()
Chris@0:    */
Chris@0:   public static function &getValue(array &$array, array $parents, &$key_exists = NULL) {
Chris@0:     $ref = &$array;
Chris@0:     foreach ($parents as $parent) {
Chris@14:       if (is_array($ref) && (isset($ref[$parent]) || array_key_exists($parent, $ref))) {
Chris@0:         $ref = &$ref[$parent];
Chris@0:       }
Chris@0:       else {
Chris@0:         $key_exists = FALSE;
Chris@0:         $null = NULL;
Chris@0:         return $null;
Chris@0:       }
Chris@0:     }
Chris@0:     $key_exists = TRUE;
Chris@0:     return $ref;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Sets a value in a nested array with variable depth.
Chris@0:    *
Chris@0:    * This helper function should be used when the depth of the array element you
Chris@0:    * are changing may vary (that is, the number of parent keys is variable). It
Chris@0:    * is primarily used for form structures and renderable arrays.
Chris@0:    *
Chris@0:    * Example:
Chris@0:    * @code
Chris@0:    * // Assume you have a 'signature' element somewhere in a form. It might be:
Chris@0:    * $form['signature_settings']['signature'] = array(
Chris@0:    *   '#type' => 'text_format',
Chris@0:    *   '#title' => t('Signature'),
Chris@0:    * );
Chris@0:    * // Or, it might be further nested:
Chris@0:    * $form['signature_settings']['user']['signature'] = array(
Chris@0:    *   '#type' => 'text_format',
Chris@0:    *   '#title' => t('Signature'),
Chris@0:    * );
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * To deal with the situation, the code needs to figure out the route to the
Chris@0:    * element, given an array of parents that is either
Chris@0:    * @code array('signature_settings', 'signature') @endcode
Chris@0:    * in the first case or
Chris@0:    * @code array('signature_settings', 'user', 'signature') @endcode
Chris@0:    * in the second case.
Chris@0:    *
Chris@0:    * Without this helper function the only way to set the signature element in
Chris@0:    * one line would be using eval(), which should be avoided:
Chris@0:    * @code
Chris@0:    * // Do not do this! Avoid eval().
Chris@0:    * eval('$form[\'' . implode("']['", $parents) . '\'] = $element;');
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * Instead, use this helper function:
Chris@0:    * @code
Chris@0:    * NestedArray::setValue($form, $parents, $element);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * However if the number of array parent keys is static, the value should
Chris@0:    * always be set directly rather than calling this function. For instance,
Chris@0:    * for the first example we could just do:
Chris@0:    * @code
Chris@0:    * $form['signature_settings']['signature'] = $element;
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * @param array $array
Chris@0:    *   A reference to the array to modify.
Chris@0:    * @param array $parents
Chris@0:    *   An array of parent keys, starting with the outermost key.
Chris@0:    * @param mixed $value
Chris@0:    *   The value to set.
Chris@0:    * @param bool $force
Chris@0:    *   (optional) If TRUE, the value is forced into the structure even if it
Chris@0:    *   requires the deletion of an already existing non-array parent value. If
Chris@0:    *   FALSE, PHP throws an error if trying to add into a value that is not an
Chris@0:    *   array. Defaults to FALSE.
Chris@0:    *
Chris@0:    * @see NestedArray::unsetValue()
Chris@0:    * @see NestedArray::getValue()
Chris@0:    */
Chris@0:   public static function setValue(array &$array, array $parents, $value, $force = FALSE) {
Chris@0:     $ref = &$array;
Chris@0:     foreach ($parents as $parent) {
Chris@0:       // PHP auto-creates container arrays and NULL entries without error if $ref
Chris@0:       // is NULL, but throws an error if $ref is set, but not an array.
Chris@0:       if ($force && isset($ref) && !is_array($ref)) {
Chris@0:         $ref = [];
Chris@0:       }
Chris@0:       $ref = &$ref[$parent];
Chris@0:     }
Chris@0:     $ref = $value;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Unsets a value in a nested array with variable depth.
Chris@0:    *
Chris@0:    * This helper function should be used when the depth of the array element you
Chris@0:    * are changing may vary (that is, the number of parent keys is variable). It
Chris@0:    * is primarily used for form structures and renderable arrays.
Chris@0:    *
Chris@0:    * Example:
Chris@0:    * @code
Chris@0:    * // Assume you have a 'signature' element somewhere in a form. It might be:
Chris@0:    * $form['signature_settings']['signature'] = array(
Chris@0:    *   '#type' => 'text_format',
Chris@0:    *   '#title' => t('Signature'),
Chris@0:    * );
Chris@0:    * // Or, it might be further nested:
Chris@0:    * $form['signature_settings']['user']['signature'] = array(
Chris@0:    *   '#type' => 'text_format',
Chris@0:    *   '#title' => t('Signature'),
Chris@0:    * );
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * To deal with the situation, the code needs to figure out the route to the
Chris@0:    * element, given an array of parents that is either
Chris@0:    * @code array('signature_settings', 'signature') @endcode
Chris@0:    * in the first case or
Chris@0:    * @code array('signature_settings', 'user', 'signature') @endcode
Chris@0:    * in the second case.
Chris@0:    *
Chris@0:    * Without this helper function the only way to unset the signature element in
Chris@0:    * one line would be using eval(), which should be avoided:
Chris@0:    * @code
Chris@0:    * // Do not do this! Avoid eval().
Chris@0:    * eval('unset($form[\'' . implode("']['", $parents) . '\']);');
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * Instead, use this helper function:
Chris@0:    * @code
Chris@0:    * NestedArray::unset_nested_value($form, $parents, $element);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * However if the number of array parent keys is static, the value should
Chris@0:    * always be set directly rather than calling this function. For instance, for
Chris@0:    * the first example we could just do:
Chris@0:    * @code
Chris@0:    * unset($form['signature_settings']['signature']);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * @param array $array
Chris@0:    *   A reference to the array to modify.
Chris@0:    * @param array $parents
Chris@0:    *   An array of parent keys, starting with the outermost key and including
Chris@0:    *   the key to be unset.
Chris@0:    * @param bool $key_existed
Chris@0:    *   (optional) If given, an already defined variable that is altered by
Chris@0:    *   reference.
Chris@0:    *
Chris@0:    * @see NestedArray::setValue()
Chris@0:    * @see NestedArray::getValue()
Chris@0:    */
Chris@0:   public static function unsetValue(array &$array, array $parents, &$key_existed = NULL) {
Chris@0:     $unset_key = array_pop($parents);
Chris@0:     $ref = &self::getValue($array, $parents, $key_existed);
Chris@14:     if ($key_existed && is_array($ref) && (isset($ref[$unset_key]) || array_key_exists($unset_key, $ref))) {
Chris@0:       $key_existed = TRUE;
Chris@0:       unset($ref[$unset_key]);
Chris@0:     }
Chris@0:     else {
Chris@0:       $key_existed = FALSE;
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Determines whether a nested array contains the requested keys.
Chris@0:    *
Chris@0:    * This helper function should be used when the depth of the array element to
Chris@0:    * be checked may vary (that is, the number of parent keys is variable). See
Chris@0:    * NestedArray::setValue() for details. It is primarily used for form
Chris@0:    * structures and renderable arrays.
Chris@0:    *
Chris@0:    * If it is required to also get the value of the checked nested key, use
Chris@0:    * NestedArray::getValue() instead.
Chris@0:    *
Chris@0:    * If the number of array parent keys is static, this helper function is
Chris@0:    * unnecessary and the following code can be used instead:
Chris@0:    * @code
Chris@0:    * $value_exists = isset($form['signature_settings']['signature']);
Chris@0:    * $key_exists = array_key_exists('signature', $form['signature_settings']);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * @param array $array
Chris@0:    *   The array with the value to check for.
Chris@0:    * @param array $parents
Chris@0:    *   An array of parent keys of the value, starting with the outermost key.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if all the parent keys exist, FALSE otherwise.
Chris@0:    *
Chris@0:    * @see NestedArray::getValue()
Chris@0:    */
Chris@0:   public static function keyExists(array $array, array $parents) {
Chris@0:     // Although this function is similar to PHP's array_key_exists(), its
Chris@0:     // arguments should be consistent with getValue().
Chris@0:     $key_exists = NULL;
Chris@0:     self::getValue($array, $parents, $key_exists);
Chris@0:     return $key_exists;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Merges multiple arrays, recursively, and returns the merged array.
Chris@0:    *
Chris@0:    * This function is similar to PHP's array_merge_recursive() function, but it
Chris@0:    * handles non-array values differently. When merging values that are not both
Chris@0:    * arrays, the latter value replaces the former rather than merging with it.
Chris@0:    *
Chris@0:    * Example:
Chris@0:    * @code
Chris@0:    * $link_options_1 = array('fragment' => 'x', 'attributes' => array('title' => t('X'), 'class' => array('a', 'b')));
Chris@0:    * $link_options_2 = array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('c', 'd')));
Chris@0:    *
Chris@0:    * // This results in array('fragment' => array('x', 'y'), 'attributes' => array('title' => array(t('X'), t('Y')), 'class' => array('a', 'b', 'c', 'd'))).
Chris@0:    * $incorrect = array_merge_recursive($link_options_1, $link_options_2);
Chris@0:    *
Chris@0:    * // This results in array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('a', 'b', 'c', 'd'))).
Chris@0:    * $correct = NestedArray::mergeDeep($link_options_1, $link_options_2);
Chris@0:    * @endcode
Chris@0:    *
Chris@0:    * @param array ...
Chris@0:    *   Arrays to merge.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The merged array.
Chris@0:    *
Chris@0:    * @see NestedArray::mergeDeepArray()
Chris@0:    */
Chris@0:   public static function mergeDeep() {
Chris@0:     return self::mergeDeepArray(func_get_args());
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Merges multiple arrays, recursively, and returns the merged array.
Chris@0:    *
Chris@0:    * This function is equivalent to NestedArray::mergeDeep(), except the
Chris@0:    * input arrays are passed as a single array parameter rather than a variable
Chris@0:    * parameter list.
Chris@0:    *
Chris@0:    * The following are equivalent:
Chris@0:    * - NestedArray::mergeDeep($a, $b);
Chris@0:    * - NestedArray::mergeDeepArray(array($a, $b));
Chris@0:    *
Chris@0:    * The following are also equivalent:
Chris@0:    * - call_user_func_array('NestedArray::mergeDeep', $arrays_to_merge);
Chris@0:    * - NestedArray::mergeDeepArray($arrays_to_merge);
Chris@0:    *
Chris@0:    * @param array $arrays
Chris@0:    *   An arrays of arrays to merge.
Chris@0:    * @param bool $preserve_integer_keys
Chris@0:    *   (optional) If given, integer keys will be preserved and merged instead of
Chris@0:    *   appended. Defaults to FALSE.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The merged array.
Chris@0:    *
Chris@0:    * @see NestedArray::mergeDeep()
Chris@0:    */
Chris@0:   public static function mergeDeepArray(array $arrays, $preserve_integer_keys = FALSE) {
Chris@0:     $result = [];
Chris@0:     foreach ($arrays as $array) {
Chris@0:       foreach ($array as $key => $value) {
Chris@0:         // Renumber integer keys as array_merge_recursive() does unless
Chris@0:         // $preserve_integer_keys is set to TRUE. Note that PHP automatically
Chris@0:         // converts array keys that are integer strings (e.g., '1') to integers.
Chris@0:         if (is_int($key) && !$preserve_integer_keys) {
Chris@0:           $result[] = $value;
Chris@0:         }
Chris@0:         // Recurse when both values are arrays.
Chris@0:         elseif (isset($result[$key]) && is_array($result[$key]) && is_array($value)) {
Chris@0:           $result[$key] = self::mergeDeepArray([$result[$key], $value], $preserve_integer_keys);
Chris@0:         }
Chris@0:         // Otherwise, use the latter value, overriding any previous value.
Chris@0:         else {
Chris@0:           $result[$key] = $value;
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:     return $result;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Filters a nested array recursively.
Chris@0:    *
Chris@0:    * @param array $array
Chris@0:    *   The filtered nested array.
Chris@0:    * @param callable|null $callable
Chris@0:    *   The callable to apply for filtering.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The filtered array.
Chris@0:    */
Chris@0:   public static function filter(array $array, callable $callable = NULL) {
Chris@0:     $array = is_callable($callable) ? array_filter($array, $callable) : array_filter($array);
Chris@0:     foreach ($array as &$element) {
Chris@0:       if (is_array($element)) {
Chris@0:         $element = static::filter($element, $callable);
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $array;
Chris@0:   }
Chris@0: 
Chris@0: }