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