So I have an associative array that's been passed via JQuery to my PHP page that contains the structure of a menu. This effectively comes in as something like this:
[{"id":1,"children":[{"id":2,"children":[{"id":3},{"id":4}]},{"id":5}]}]
I've decoded the string and made it into an associative array using json_decode like so:
$cleanJSON = json_decode($JSON,true);
This is all fine so far and gives the result like this:
Array (
[0] => Array
(
[id] => 1
[children] => Array
(
[0] => Array
(
[id] => 2
[children] => Array
(
[0] => Array
(
[id] => 3
)
[1] => Array
(
[id] => 4
)
)
)
[1] => Array
(
[id] => 5
)
)
)
)
The problem I'm having is I now need to figure out the left and right nested set values of each item so that I can update my database with this new structure.
The reason I'm doing this is to allow me to accomplish reordering menu items within the nested set model.
Getting a resulting array which looks something like the below example would be perfect:
Array (
[0] => Array
(
[id] => 1
[left] => 1
[right] => 10
)
[1] => Array
(
[id] => 2
[left] => 2
[right] => 7
)
[2] => Array
(
[id] => 3
[left] => 3
[right] => 4
)
[3] => Array
(
[id] => 4
[left] => 5
[right] => 6
)
[4] => Array
(
[id] => 5
[left] => 8
[right] => 9
)
)
The below code is a mess and doesn't work at all, but it's as far as I got with it:
$i_count = 1;
$i_index = 1;
$a_newTree;
function recurseTree($nestedSet)
{
global $i_count;
global $a_newTree;
$i_left = $i_count;
$a_newTree[$i_count-1]['left'] = $i_left;
$i_count++;
foreach ($nestedSet AS $key => $value)
{
if ($value['children'])
{
foreach($value['children'] as $a_child)
{
recurseTree($a_child); // traverse
}
}
}
$i_right=$i_count; // right = count
$a_newTree[$i_count-1]['right'] = $i_right;
$i_count++; // count+1
}
Any help appreciated!
SOLVED!
A nifty little function created by a friend has solved this issue for me. He actually created it in Javascript but I've translated it over to PHP. I'll supply both below.
The PHP Version first:
$JSON = '[{"id":1,"children":[{"id":2,"children":[{"id":3},{"id":4}]},{"id":5}]}]';
$cleanJSON = json_decode($JSON,true);
$a_newTree = array();
function recurseTree($structure,$previousLeft)
{
global $a_newTree; // Get global Variable to store results in.
$indexed = array(); // Bucket of results.
$indexed['id'] = $structure['id']; // Set ID
$indexed['left'] = $previousLeft + 1; // Set Left
$lastRight = $indexed['left'];
$i_count = 0;
if ($structure['children'])
{
foreach ($structure['children'] as $a_child)
{
$lastRight = recurseTree($structure['children'][$i_count],$lastRight);
$i_count++;
}
}
$indexed['right'] = $lastRight + 1; // Set Right
array_push($a_newTree,$indexed); // Push onto stack
return $indexed['right'];
}
recurseTree($cleanJSON[0],0);
print_r($a_newTree);
Fantastic little function outputs the exact array required.
OK, For the original JAVASCRIPT version my friend wrote, see below:
<html>
<head>
<title>Experiment</title>
<script type="text/javascript">
/* initial structure */
var struct = [
{
"id": 1,
"children": [{
"id": 2,
"children": [{
"id": 3
}, {
"id": 4
}]
}, {
"id": 5
}]
}
];
function experiment() {
/* stores all results */
var all = [];
/* kick off the recursive method */
handleNode(struct[0], 0, all);
/* print the results to browser debugger console*/
console.log(all);
}
function handleNode(node, previousLeft, all) {
/* create and store the new entry (bucket to put left, right, and id ) */
var indexed = {};
all.push(indexed);
indexed.id = node["id"];
indexed.left = previousLeft + 1;
var lastRight = indexed.left;
/* here we do the recursion for every child */
for (var x in node["children"]) {
lastRight = handleNode(node["children"][x], lastRight, all);
}
/* once all children have been iterated over we can store the rigth */
indexed.right = lastRight + 1;
/* return the newly updated right for this bucket */
return indexed.right;
}
/* run the experiment */
experiment();
</script>
</head>
<body>
</body>
</html>
Using Google Chrome you can see the results in the Console window. (CTRL-SHIFT-i).