Create html select list from php array? - php

Question

Hello I find php function that outputs html select list from array.
function buildTree(Array $data, $parent = 0) {
$tree = array();
foreach ($data as $d) {
if ($d['parent'] == $parent) {
$children = buildTree($data, $d['id']);
// set a trivial key
if (!empty($children)) {
$d['_children'] = $children;
}
$tree[] = $d;
}
}
return $tree;
}
$rows = array(
array ('id' => 1, 'name' => 'Test 1', 'parent' => 0),
array ('id' => 2, 'name' => 'Test 1.1', 'parent' => 1),
array ('id' => 3, 'name' => 'Test 1.2', 'parent' => 1),
array ('id' => 4, 'name' => 'Test 1.2.1', 'parent' => 3),
array ('id' => 5, 'name' => 'Test 1.2.2', 'parent' => 3),
array ('id' => 6, 'name' => 'Test 1.2.2.1', 'parent' => 5),
array ('id' => 7, 'name' => 'Test 2', 'parent' => 0),
array ('id' => 8, 'name' => 'Test 2.1', 'parent' => 7),
);
$tree = buildTree($rows);
// print_r($tree);
function printTree($tree, $r = 0, $p = null) {
foreach ($tree as $i => $t) {
$dash = ($t['parent'] == 0) ? '' : str_repeat('-', $r) .' ';
printf("\t<option value='%d'>%s%s</option>\n", $t['id'], $dash, $t['name']);
if ($t['parent'] == $p) {
// reset $r
$r = 0;
}
if(isset($t['_children'])){
printTree($t['_children'], ++$r, $t['parent']);
}
}
}
print("<select>\n");
printTree($tree);
print("</select>");
but I need to rewrite to return result like this:
$select = "<select>";
$select .= printTree($list);
$select .= "</select>";
echo $select;
// or better
return $select;
The problem is with recursion, solution is to fill each option in array, but I don't know how to do that in recursive functions, and also
printf("\t<option value='%d'>%s%s</option>\n", $t['id'], $dash, $t['name']);
prints directly when foreach loop iterate.
Thanks.

Answer 1

So i figure out where was my mistake, that was simply because i fill an array with html option tag eg.
<option value="0">Start</option>
but with php function print_r() i see nothing in array value exepts when i inspect DOM element.
so here is my final solution:
this function fill values in multi dimensional array, to further needs
# edited printTree() function, renamed to toSEL()
# $array - data array like above,
# $r - to correct iterate, $p - parent id,
# $currentID - what id is selected
function toSEL($array, $r = 0, $p = null, $currentID=null){
foreach($array as $value){
$dash = ($value[parent] == 0) ? '' : str_repeat('-', $r) .' ';
if($value[id]==$currentID){
$html[] = '<option value="'.$value[id].'" selected="selected">'.$dash.$value[name].'</option>';
}else{
$html[] = '<option value="'.$value[id].'">'.$dash.$value[name].'</option>';
}
if($value['parent'] == $p){
// reset $r
$r = 0;
}
if(!empty($value[children])){
$html[] = toSEL($value[children], ++$r, $value[parent], $currentID);
}
}
return $html;
}
to convert from multi dimensional array to one dimension
$aNonFlat = toSEL($list, 0, null, $currentID);
$result = array();
array_walk_recursive($aNonFlat,function($v, $k) use (&$result){ $result[] = $v; });
then if needs to output HTML use some simple loop.
$html = '<select>';
foreach($result as $res){
$html .= $res;
}
$html .='</select>';
echo $html;