Schema.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Form;

/**
 * Contains the schema information for Form instances.
 */
class Schema {

/**
 * The fields in this schema.
 *
 * @var array
 */
	protected $_fields = [];

/**
 * The default values for fields.
 *
 * @var array
 */
	protected $_fieldDefaults = [
		'type' => null,
		'length' => null,
		'precision' => null,
	];

/**
 * Add multiple fields to the schema.
 *
 * @param array $fields The fields to add.
 * @return $this
 */
	public function addFields(array $fields) {
		foreach ($fields as $name => $attrs) {
			$this->addField($name, $attrs);
		}
		return $this;
	}

/**
 * Adds a field to the schema.
 *
 * @param string $name The field name.
 * @param string|array $attrs The attributes for the field, or the type
 *   as a string.
 * @return $this
 */
	public function addField($name, $attrs) {
		if (is_string($attrs)) {
			$attrs = ['type' => $attrs];
		}
		$attrs = array_intersect_key($attrs, $this->_fieldDefaults);
		$this->_fields[$name] = $attrs + $this->_fieldDefaults;
		return $this;
	}

/**
 * Removes a field to the schema.
 *
 * @param string $name The field to remove.
 * @return $this
 */
	public function removeField($name) {
		unset($this->_fields[$name]);
		return $this;
	}

/**
 * Get the list of fields in the schema.
 *
 * @return array The list of field names.
 */
	public function fields() {
		return array_keys($this->_fields);
	}

/**
 * Get the attributes for a given field.
 *
 * @param string $name The field name.
 * @return null|array The attributes for a field, or null.
 */
	public function field($name) {
		if (!isset($this->_fields[$name])) {
			return null;
		}
		return $this->_fields[$name];
	}

/**
 * Get the type of the named field.
 *
 * @param string $field The name of the field.
 * @return string|null Either the field type or null if the
 *   field does not exist.
 */
	public function fieldType($name) {
		$field = $this->field($name);
		if (!$field) {
			return null;
		}
		return $field['type'];
	}

}