getting garbage values while converting Yii model object to JSON - php

Question

i have a model class which extends CComponent
class CompanyModel extends CComponent{
private $company_pk;
public function getCompany_pk()
{
return $this->company_pk;
}
public function setCompany_pk($value) {
$this->company_pk = $value;
}
}
I have a function which fills this modal
public function getCompanyList() {
$companyList=array();
$company_obj = new CompanyModel();
$sql = "SELECT company_pk,name FROM tbl_company WHERE status = ".Constants::ACTIVE_COMPANY;
$command=$this->connection->createCommand($sql);
$command->setFetchMode(PDO::FETCH_ASSOC);
$rows=$command->queryAll();
foreach ($rows as $row){
$company_obj->company_pk = $row['company_pk'];
array_push($companyList,$company_obj);
}
return $companyList;
}
and my controller
Class UserController extends CController {
public function actionGetCompanyList() {
$model = new UserAction();
$ret_val = $model->getCompanyList();
echo CJSON::encode((array)$ret_val[0]);
}
}
and the JSON i get is
{"\u0000CompanyModel\u0000company_pk":"2"}
How can i remove those garbage values

Answer 1

I asume you can't decode them later, if you would change $company_pk to public it should encode correctly. Problem is with your object cast to array which adds NULL byte to your private member $company_pk. In echo CJSON::encode((array)$ret_val[0]); as it's array of OBJECTS.
You can do nasty.
$json = '{"\u0000CompanyModel\u0000company_pk":"2"}';
$json = str_replace('\u0000', '', $json);
var_dump(json_decode($json));
Or you pass object to CJSON::encode i dont know much of YII but it should handle object, as per manual http://www.yiiframework.com/doc/api/1.1/CJSON.
Here is example to reproduce issue:
class test {
private $private = 1;
public $publiv = 2;
}
$obj = new test();
$array = (array) $obj;
$json = json_encode($array);
var_dump($json);
var_dump(json_decode($json));
EDIT:
From the manual http://www.php.net/manual/en/language.types.array.php:
If an object is converted to an array, the result is an array whose elements are the object's properties. The keys are the member variable names, with a few notable exceptions: integer properties are unaccessible; private variables have the class name prepended to the variable name; protected variables have a '*' prepended to the variable name. These prepended values have null bytes on either side.
I did quick look to CJSON::encode from YII and you can use object directly, but your object must be traversable, so you must implement Iterator interface. http://www.php.net/manual/en/class.iterator.php.
EDIT:2
Implementing interface could be tricky, there is another option to call get_object_vars from within object and in this case you will get array which will work.
class CompanyModel extends CComponent
{
private $company_pk;
public function getCompany_pk()
{
return $this->company_pk;
}
public function setCompany_pk($value)
{
$this->company_pk = $value;
}
public function export()
{
return get_object_vars($this);
}
}
And then:
$ret_val = $model->getCompanyList();
echo CJSON::encode($ret_val->export());
Problem why it does not work for you with normal object because YII uses get_object_vars internally and it can't access private properties when it's in different scope.

Answer 2

I found out that if i extend CModel instead of CComponent in the model class, i could achieve what exactly i wanted. While extending this class you will have to override one abstract method. Otherwise it will throw error. My new Model class look like this
class CompanyModel extends CModel{
private $company_pk;
public function attributeNames()
{
return array( 'company_pk' );
}
public function attributeLabels()
{
return array( 'company_pk' => 'company_pk Label' );
}
public function getCompany_pk()
{
return $this->company_pk;
}
public function setCompany_pk($value) {
$this->company_pk = $value;
}
}