Yii: change active record field names - yii

Question

I'm new to Yii and I have a table 'Student' with fields like 'stdStudentId', 'stdName', etc.
I'm making API, so this data should be returned in JSON. Now, because I want field names in JSON to just be like 'id', 'name', and I don't want all fields returned, i made a method in the model:
public function APIfindByPk($id){
$student = $this->findByPk($id);
return array(
'id'=>$student->stdStudentId,
'name'=>$student->stdName,
'school'=>$student->stdSchool
);
}
The problem is, stdSchool is a relation and in this situation, $student->stdSchool returns array with fields like schSchoolId, schName, etc. I don't want fields to be named like that in JSON, and also I don't want all the fields from School returned and I would like to add some fields of my own. Is there a way to do this in Yii, or I'll have to do it manually by writing methods like this?

Answer 1

I have been looking for the same thing. There is a great php lib named Fractal letting you achieve it: http://fractal.thephpleague.com/
To explain briefly the lib, for each of your models you create a Transformer that will be doing the mapping between your model attributes and the ones that need to be exposed using the api.
class BookTransformer extends Fractal\TransformerAbstract
{
public function transform(Book $book)
{
return [
'id' => (int) $book->id,
'title' => $book->title,
'year' => $book->yr,
];
}
}
In the transformer you can also set the relation that this model have :
class BookTransformer extends TransformerAbstract
{
/**
* List of resources relations that can be used
*
* #var array
*/
protected $availableEmbeds = [
'author'
];
/**
* Turn this item object into a generic array
*
* #return array
*/
public function transform(Book $book)
{
return [
'id' => (int) $book->id,
'title' => $book->title,
'year' => $book->yr,
];
}
/**
* Here we are embeding the author of the book
* using it's own transformer
*/
public function embedAuthor(Book $book)
{
$author = $book->author;
return $this->item($author, new AuthorTransformer);
}
}
So at the end you will call
$fractal = new Fractal\Manager();
$resource = new Fractal\Resource\Collection($books, new BookTransformer);
$json = $fractal->createData($resource)->toJson();
It's not easy to describe all the potential of fractal in one answer but you really should give it a try.
I'm using it along with Yii so if you have some question don't hesitate!

Answer 2

Since you are getting the values from the database using Yii active record, ask the database to use column aliases.
Normal SQL would be something like the following :
SELECT id AS Student_Number, name AS Student_Name, school AS School_Attending FROM student;
In Yii, you can apply Criteria to the findByPK() function. See here for reference : http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findByPk-detail
$criteria = new CDbCriteria();
$criteria->select = 'id AS Student_Number';
$student = Student::model()->findByPk($id, $criteria);
Note that in order to use a column alias like that, you will have to define a virtual attribute Student_Number in your Student{} model.

Answer 3

Override the populateRecord() function of ActiveRecord can achieve this!
My DishType has 5 properties and override the populateRecord function Yii would invoke this when records fetched from db.
My code is here!
class DishType extends ActiveRecord
{
public $id;
public $name;
public $sort;
public $createTime;
public $updateTime;
public static function populateRecord($record, $row)
{
$pattern = ['id' => 'id', 'name' => 'name', 'sort' => 'sort', 'created_at' => 'createTime', 'updated_at' => 'updateTime'];
$columns = static::getTableSchema()->columns;
foreach ($row as $name => $value) {
$propertyName = $pattern[$name];
if (isset($pattern[$name]) && isset($columns[$name])) {
$record[$propertyName] = $columns[$name]->phpTypecast($value);
}
}
parent::populateRecord($record, $row);
}
}