rest WIP

framework/base/Model.php

@@ -13,6 +13,7 @@ use ArrayObject;
 use ArrayIterator;
 use ReflectionClass;
 use IteratorAggregate;
+use yii\helpers\ArrayHelper;
 use yii\helpers\Inflector;
 use yii\validators\RequiredValidator;
 use yii\validators\Validator;
@@ -789,13 +790,130 @@ class Model extends Component implements IteratorAggregate, ArrayAccess, Arrayab
 	}
 
 	/**
+	 * Returns the list of fields that should be returned by default by [[toArray()]] when no specific fields are specified.
+	 *
+	 * A field is a named element in the returned array by [[toArray()]].
+	 *
+	 * This method should return an array of field names or field definitions.
+	 * If the former, the field name will be treated as an object property name whose value will be used
+	 * as the field value. If the latter, the array key should be the field name while the array value should be
+	 * the corresponding field definition which can be either an object property name or a PHP callable
+	 * returning the corresponding field value. The signature of the callable should be:
+	 *
+	 * ```php
+	 * function ($field, $model) {
+	 *     // return field value
+	 * }
+	 * ```
+	 *
+	 * For example, the following code declares four fields:
+	 *
+	 * - `email`: the field name is the same as the property name `email`;
+	 * - `firstName` and `lastName`: the field names are `firstName` and `lastName`, and their
+	 *   values are obtained from the `first_name` and `last_name` properties;
+	 * - `fullName`: the field name is `fullName`. Its value is obtained by concatenating `first_name`
+	 *   and `last_name`.
+	 *
+	 * ```php
+	 * return [
+	 *     'email',
+	 *     'firstName' => 'first_name',
+	 *     'lastName' => 'last_name',
+	 *     'fullName' => function () {
+	 *         return $this->first_name . ' ' . $this->last_name;
+	 *     },
+	 * ];
+	 * ```
+	 *
+	 * In this method, you may also want to return different lists of fields based on some context
+	 * information. For example, depending on privilege of the current application user, you may return different
+	 * sets of visible fields.
+	 *
+	 * The default implementation of this method returns [[attributes()]] indexed by the same attribute names.
+	 *
+	 * @return array the list of field names or field definitions.
+	 * @see toArray()
+	 */
+	public function fields()
+	{
+		$fields = $this->attributes();
+		return array_combine($fields, $fields);
+	}
+
+	/**
+	 * Returns the list of fields that can be expanded further and returned by [[toArray()]].
+	 *
+	 * This method is similar to [[fields()]] except that the list of fields returned
+	 * by this method are not returned by default by [[toArray()]]. Only when field names
+	 * to be expanded are explicitly specified when calling [[toArray()]], will their values
+	 * be exported.
+	 *
+	 * The default implementation returns an empty array.
+	 *
+	 * @return array the list of expandable field names or field definitions. Please refer
+	 * to [[fields()]] on the format of the return value.
+	 * @see toArray()
+	 * @see fields()
+	 */
+	public function expandableFields()
+	{
+		return [];
+	}
+
+	/**
 	 * Converts the object into an array.
 	 * The default implementation will return [[attributes]].
+	 * @param array $fields the fields being requested. If empty, all fields as specified by [[fields()]] will be returned.
+	 * @param array $expand the additional fields being requested for exporting. Only fields declared in [[expandableFields()]]
+	 * will be considered.
+	 * @param boolean $recursive whether to recursively return array representation of embedded objects.
 	 * @return array the array representation of the object
 	 */
-	public function toArray()
+	public function toArray(array $fields = [], array $expand = [], $recursive = true)
+	{
+		$data = [];
+		foreach ($this->resolveFields($fields, $expand) as $field => $definition) {
+			$data[$field] = is_string($definition) ? $this->$definition : call_user_func($definition, $field, $this);
+		}
+		return $recursive ? ArrayHelper::toArray($data) : $data;
+	}
+
+	/**
+	 * Determines which fields can be returned by [[toArray()]].
+	 * This method will check the requested fields against those declared in [[fields()]] and [[expandableFields()]]
+	 * to determine which fields can be returned.
+	 * @param array $fields the fields being requested for exporting
+	 * @param array $expand the additional fields being requested for exporting
+	 * @return array the list of fields to be exported. The array keys are the field names, and the array values
+	 * are the corresponding object property names or PHP callables returning the field values.
+	 */
+	protected function resolveFields(array $fields, array $expand)
 	{
-		return $this->getAttributes();
+		$result = [];
+
+		foreach ($this->fields() as $field => $definition) {
+			if (is_integer($field)) {
+				$field = $definition;
+			}
+			if (empty($fields) || in_array($field, $fields, true)) {
+				$result[$field] = $definition;
+			}
+		}
+
+		if (empty($expand)) {
+			return $result;
+		}
+
+		foreach ($this->expandableFields() as $field => $definition) {
+			if (is_integer($field)) {
+				$field = $definition;
+			}
+			if (in_array($field, $expand, true)) {
+				$result[$field] = $definition;
+			}
+		}
+
+		return $result;
 	}
 
 	/**

framework/db/BaseActiveRecord.php

@@ -19,8 +19,6 @@ use yii\base\InvalidCallException;
 /**
  * ActiveRecord is the base class for classes representing relational data in terms of objects.
  *
- * @include @yii/db/ActiveRecord.md
- *
  * @property array $dirtyAttributes The changed attribute values (name-value pairs). This property is
  * read-only.
  * @property boolean $isNewRecord Whether the record is new and should be inserted when calling [[save()]].
@@ -1346,4 +1344,26 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
 
 		return $this->generateAttributeLabel($attribute);
 	}
+
+	/**
+	 * @inheritdoc
+	 *
+	 * The default implementation returns the names of the columns whose values have been populated into this record.
+	 */
+	public function fields()
+	{
+		$fields = array_keys($this->_attributes);
+		return array_combine($fields, $fields);
+	}
+
+	/**
+	 * @inheritdoc
+	 *
+	 * The default implementation returns the names of the relations that have been populated into this record.
+	 */
+	public function expandableFields()
+	{
+		$fields = array_keys($this->getRelatedRecords());
+		return array_combine($fields, $fields);
+	}
 }

framework/helpers/BaseArrayHelper.php

@@ -58,7 +58,17 @@ class BaseArrayHelper
 	 */
 	public static function toArray($object, $properties = [], $recursive = true)
 	{
-		if (!empty($properties) && is_object($object)) {
+		if (is_array($object)) {
+			if ($recursive) {
+				foreach ($object as $key => $value) {
+					if (is_array($value) || is_object($value)) {
+						$object[$key] = static::toArray($value, true);
+					}
+				}
+			}
+			return $object;
+		} elseif (is_object($object)) {
+			if (!empty($properties)) {
 				$className = get_class($object);
 				if (!empty($properties[$className])) {
 					$result = [];
@@ -69,24 +79,21 @@ class BaseArrayHelper
 							$result[$key] = static::getValue($object, $name);
 						}
 					}
-				return $result;
+					return $recursive ? static::toArray($result) : $result;
 				}
 			}
 			if ($object instanceof Arrayable) {
-			$object = $object->toArray();
-			if (!$recursive) {
-				return $object;
-			}
-		}
+				$result = $object->toArray();
+			} else {
 				$result = [];
 				foreach ($object as $key => $value) {
-			if ($recursive && (is_array($value) || is_object($value))) {
-				$result[$key] = static::toArray($value, true);
-			} else {
 					$result[$key] = $value;
 				}
 			}
-		return $result;
+			return $recursive ? static::toArray($result) : $result;
+		} else {
+			return [$object];
+		}
 	}
 
 	/**