framework/base/ArrayableTrait.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\base;
use Yii;
use yii\helpers\ArrayHelper;
use yii\web\Link;
use yii\web\Linkable;
/**
* ArrayableTrait provides a common implementation of the [[Arrayable]] interface.
*
* ArrayableTrait implements [[toArray()]] by respecting the field definitions as declared
* in [[fields()]] and [[extraFields()]].
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
trait ArrayableTrait
{
/**
* 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 ($model, $field) {
* // 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 the privilege of the current application user,
* you may return different sets of visible fields or filter out some fields.
*
* The default implementation of this method returns the public object member variables indexed by themselves.
*
* @return array the list of field names or field definitions.
* @see toArray()
*/
public function fields()
{
$fields = array_keys(Yii::getObjectVars($this));
return array_combine($fields, $fields);
}
/**
* Returns the list of fields that can be expanded further and returned by [[toArray()]].
*
* This method is similar to [[fields()]] except that the list of fields returned
* by this method are not returned by default by [[toArray()]]. Only when field names
* to be expanded are explicitly specified when calling [[toArray()]], will their values
* be exported.
*
* The default implementation returns an empty array.
*
* You may override this method to return a list of expandable fields based on some context information
* (e.g. the current application user).
*
* @return array the list of expandable field names or field definitions. Please refer
* to [[fields()]] on the format of the return value.
* @see toArray()
* @see fields()
*/
public function extraFields()
{
return [];
}
/**
* Converts the model into an array.
*
* This method will first identify which fields to be included in the resulting array by calling [[resolveFields()]].
* It will then turn the model into an array with these fields. If `$recursive` is true,
* any embedded objects will also be converted into arrays.
* When embedded objects are [[Arrayable]], their respective nested fields will be extracted and passed to [[toArray()]].
*
* If the model implements the [[Linkable]] interface, the resulting array will also have a `_link` element
* which refers to a list of links as specified by the interface.
*
* @param array $fields the fields being requested.
* If empty or if it contains '*', all fields as specified by [[fields()]] will be returned.
* Fields can be nested, separated with dots (.). e.g.: item.field.sub-field
* `$recursive` must be true for nested fields to be extracted. If `$recursive` is false, only the root fields will be extracted.
* @param array $expand the additional fields being requested for exporting. Only fields declared in [[extraFields()]]
* will be considered.
* Expand can also be nested, separated with dots (.). e.g.: item.expand1.expand2
* `$recursive` must be true for nested expands to be extracted. If `$recursive` is false, only the root expands will be extracted.
* @param bool $recursive whether to recursively return array representation of embedded objects.
* @return array the array representation of the object
*/
public function toArray(array $fields = [], array $expand = [], $recursive = true)
{
$data = [];
foreach ($this->resolveFields($fields, $expand) as $field => $definition) {
$attribute = is_string($definition) ? $this->$definition : $definition($this, $field);
if ($recursive) {
$nestedFields = $this->extractFieldsFor($fields, $field);
$nestedExpand = $this->extractFieldsFor($expand, $field);
if ($attribute instanceof Arrayable) {
$attribute = $attribute->toArray($nestedFields, $nestedExpand);
} elseif ($attribute instanceof \JsonSerializable) {
$attribute = $attribute->jsonSerialize();
} elseif (is_array($attribute)) {
$attribute = array_map(
function ($item) use ($nestedFields, $nestedExpand) {
if ($item instanceof Arrayable) {
return $item->toArray($nestedFields, $nestedExpand);
} elseif ($item instanceof \JsonSerializable) {
return $item->jsonSerialize();
}
return $item;
},
$attribute
);
}
}
$data[$field] = $attribute;
}
if ($this instanceof Linkable) {
$data['_links'] = Link::serialize($this->getLinks());
}
return $recursive ? ArrayHelper::toArray($data) : $data;
}
/**
* Extracts the root field names from nested fields.
* Nested fields are separated with dots (.). e.g: "item.id"
* The previous example would extract "item".
*
* @param array $fields The fields requested for extraction
* @return array root fields extracted from the given nested fields
* @since 2.0.14
*/
protected function extractRootFields(array $fields)
{
$result = [];
foreach ($fields as $field) {
$result[] = current(explode('.', $field, 2));
}
if (in_array('*', $result, true)) {
$result = [];
}
return array_unique($result);
}
/**
* Extract nested fields from a fields collection for a given root field
* Nested fields are separated with dots (.). e.g: "item.id"
* The previous example would extract "id".
*
* @param array $fields The fields requested for extraction
* @param string $rootField The root field for which we want to extract the nested fields
* @return array nested fields extracted for the given field
* @since 2.0.14
*/
protected function extractFieldsFor(array $fields, $rootField)
{
$result = [];
foreach ($fields as $field) {
if (0 === strpos($field, "{$rootField}.")) {
$result[] = preg_replace('/^' . preg_quote($rootField, '/') . '\./i', '', $field);
}
}
return array_unique($result);
}
/**
* Determines which fields can be returned by [[toArray()]].
* This method will first extract the root fields from the given fields.
* Then it will check the requested root fields against those declared in [[fields()]] and [[extraFields()]]
* 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)
{
$fields = $this->extractRootFields($fields);
$expand = $this->extractRootFields($expand);
$result = [];
foreach ($this->fields() as $field => $definition) {
if (is_int($field)) {
$field = $definition;
}
if (empty($fields) || in_array($field, $fields, true)) {
$result[$field] = $definition;
}
}
if (empty($expand)) {
return $result;
}
foreach ($this->extraFields() as $field => $definition) {
if (is_int($field)) {
$field = $definition;
}
if (in_array($field, $expand, true)) {
$result[$field] = $definition;
}
}
return $result;
}
}