I have data in a MYSQL DB that looks like this:
id,parentid,name,count
1,0,top,10
2,1,middle1,5
3,1,middle2,5
4,3,bottom1,3
5,3,bottom2,2
and want to output it via PHP as a heirarchical JSON string where 'top' has a collection of 'middle's etc.
Get my drift? Anyone have a recursive PHP function to help?
if you've got your data in a PHP array/associative array, then you can use PHP 5.2's JSON functions:
http://www.php.net/manual/en/function.json-encode.php
keep reading on that page to the comments area, they practically give away the code without the fun of figuring it out yourself.
You can use the function here http://tagarga.com/blok/on/061029 to convert your adjacency list to a nested array, then json_encode() it.
function adj_tree(&$tree, $item) {
$i = $item['id'];
$p = $item['parentid'];
$tree[$i] = isset($tree[$i]) ? $item + $tree[$i] : $item;
$tree[$p]['_children'][] = &$tree[$i];
}
$tree = array();
$rs = my_query("SELECT * FROM categories");
while($row = my_fetch($rs))
adj_tree($tree, $row);
echo json_encode($tree[0]);
