How to create nested PHP value object? (class) - php

Question

I would like to create the following using class syntax:
$resp = new stdclass;
$resp->CategoryListResp->category[0]->categoryId = 1;
$resp->CategoryListResp->category[0]->categoryName = "Spel";
$resp->CategoryListResp->category[0]->iconUri = "PictoSpel.png";
$resp->CategoryListResp->category[1]->categoryId = 2;
$resp->CategoryListResp->category[1]->categoryName = "Transport";
$resp->CategoryListResp->category[1]->iconUri = "PictoTransport.png";
Should be easy but I cannot find the syntax for this.
I will later output $resp in json format. I am aware I can also use arrays for this...
The json output shall be:
{"CategoryListResp":{"category":[{"categoryId":1,"categoryName":"Spel","iconUri":"PictoSpel.png"},{"categoryId":2,"categoryName":"Transport","iconUri":"PictoTransport.png"}]}}

Answer 1

You can also make your classes more explicit:
class Category {
public $categoryId = 0, $categoryName = '', $iconUri = '';
}
class Resp {
public $categoryListResp = null;
public function __construct() {
$this->categoryListResp = new CategoryListResp();
}
}
class CategoryListResp {
public $category = array();
}
$resp = new Resp();
$resp->categoryListResp->category[0]->categoryId = 1;
$resp->categoryListResp->category[0]->categoryName = "Spel";
$resp->categoryListResp->category[0]->iconUri = "PictoSpel.png";
// etc.
ADDED (based on henq's comment). To fully utilize the class concept you would need to add some methods to the classes. Then you would not use -> for arrays, but call the respective methods. E.g.
class Category {
public $categoryId = 0, $categoryName = '', $iconUri = '';
public function __construct($id, $name, $icon) {
$this->categoryId = $id;
$this->categoryName = $name;
$this->iconUri = $icon;
}
}
class Resp {
public $categoryListResp = null;
public function __construct() {
$this->categoryListResp = new CategoryListResp();
}
public function addCategory($index, $id, $name, $icon) {
$this->categoryListResp->addCategory($index, $id, $name, $icon);
}
}
class CategoryListResp {
public $category = array();
public function addCategory($index, $id, $name, $icon) {
$this->category[$index] = new Category($id, $name, $icon);
}
}
$resp = new Resp();
$resp->addCategory(0, 1, "Spel", "PictoSpel.png");
$resp->addCategory(1, 2, "Transport", "PictoTransport.png");
// etc
You can modify this concept according to your needs.

Answer 2

You're almost there already:
$resp = new stdClass();
$resp->CategoryListResp = new stdClass();
$resp->CategoryListResp->category[0]->categoryId = 1;
$resp->CategoryListResp->category[0]->categoryName = "Spel";
$resp->CategoryListResp->category[0]->iconUri = "PictoSpel.png";
$resp->CategoryListResp->category[1]->categoryId = 2;
$resp->CategoryListResp->category[1]->categoryName = "Transport";
$resp->CategoryListResp->category[1]->iconUri = "PictoTransport.png";
print_r(json_encode($resp));
/*
output:
{"CategoryListResp":{"category":[{"categoryId":1,"categoryName":"Spel","iconUri":"PictoSpel.png"},{"categoryId":2,"categoryName":"Transport","iconUri":"PictoTransport.png"}]}}
*/
Just send $resp to json_encode. Your code should work as is, however. It's better design to create class definitions for CategoryListResp and Category, rather than just using stdClass.

Answer 3

Arrays are the simpler way to go (as suggested by #felix-kling)
This is how the code ended up:
$resp = array(
'CategoryListResp' => array(
'category' => array(
array(
'categoryId' => 1,
'categoryName' => 'Spel',
'iconUri' => 'PictoSpel.png'
),
array(
'categoryId' => 2,
'categoryName' => 'Transport',
'iconUri' => 'PictoTransport.png'
),
),
),
);
print json_encode($resp);
Clean and simple.