PHP Adjacency List to Nested Array - php

Question

I am trying to convert following table data into nested array using PHP. I am almost done but stuck at one point.
id name parent
1 Apparel
2 Appliances
46 Apparel 1
47 Child Apparel 46
49 Child Apparel 2 47
Using this code
$cats = array(); // from database
$refs = array();
$rcats = array();
foreach ($cats as $cat) {
$thisref = &$refs[$cat['id']];
$thisref['id'] = $cat['id'];
$thisref['name'] = $cat['name'];
$thisref['leaf'] = "true";
if (!$cat['parent']) {
$rcats[$cat['id']] = &$thisref;
} else {
unset($refs[$cat['parent']]['leaf']);
$refs[$cat['parent']]['items'][$cat['id']] = &$thisref;
}
}
print_r(json_encode($rcats));
This results into following JSON.
{
"1": {
"id": "1",
"name": "Apparel",
"items": {
"46": {
"id": "46",
"name": "Apparel",
"items": {
"47": {
"id": "47",
"name": "Child Apparel",
"items": {
"49": {
"id": "49",
"name": "Child Apparel 2",
"leaf": "true"
}
}
}
}
}
}
},
"2": {
"id": "2",
"name": "Appliances",
"leaf": "true"
}
}
Where as I want the JSON like
[
{
"id": "1",
"name": "Apparel",
"items": [
{
"id": "46",
"name": "Apparel",
"items": [
{
"id": "47",
"name": "Child Apparel",
"items": [
{
"id": "49",
"name": "Child Apparel 2",
"leaf": "true"
}
]
}
]
}
]
},
{
"id": "2",
"name": "Appliances",
"leaf": "true"
}
]

Answer 1

Am i wrong? :p
$cats = array(); // From Database, but i use this
$cats = array(
array(
'id' => 1,
'name' => 'Jakarta',
'parent' => NULL
),
array(
'id' => 2,
'name' => 'Bandung',
'parent' => 1
),
array(
'id' => 3,
'name' => 'Surabaya',
'parent' => 1
),
array(
'id' => 4,
'name' => 'Bali',
'parent' => NULL
),
array(
'id' => 5,
'name' => 'Batam',
'parent' => NULL
),
);
$refs = array();
$rcats = array();
foreach ($cats as $cat) {
$thisref = &$refs[$cat['id']];
$thisref['id'] = $cat['id'];
$thisref['name'] = $cat['name'];
$thisref['leaf'] = "true";
if (!$cat['parent']) {
$rcats[] = &$thisref;
}
else {
unset($refs[$cat['parent']]['leaf']);
$refs[$cat['parent']]['items'][] = &$thisref;
}
}
/*
// IF YOU NEED CHANGE TO OBJECT
$rcats = (object)$rcats;
if(isset($rcats->items)){
$rcats->items = (object)$rcats->items;
}
*/
header('Content-type: application/json');
print_r(json_encode($rcats));

Answer 2

Here I'm assuming you are storing your final results in $refs
print_r(json_encode(array_values($rcats)));
If you want to take out all the indexes, in your for loop, do [] instead of the id:
if (!$cat['parent']) {
$rcats[] = &$thisref;
} else {
unset($refs[$cat['parent']]['leaf']);
$refs[$cat['parent']]['items'][] = &$thisref;
}
A quick example I throw:
<?php
$a = array('1' => array('a' => 3), '2' => array('b' => 4));
echo json_encode($a) . "\n";
echo json_encode(array_values($a)) . "\n";
Outputs:
{"1":{"a":3},"2":{"b":4}}
[{"a":3},{"b":4}]