Recursive Multidimensional Array to HTML nested code - php

Question

Im trying to create nested blocks of HTML code from a Multidimensional Array in PHP using a recursive function. However I can not seem to print the tags in a nested order.
Here is the original array:
$array_1 =
array
(
array
(
'id' => '1',
'tag' => 'div1',
'parent' => '0'
),
array
(
'id' => '2',
'tag' => 'div2',
'parent' => '1'
),
array
(
'id' => '3',
'tag' => 'div3',
'parent' => '2'
),
array
(
'id' => '4',
'tag' => 'div4',
'parent' => '2'
),
array
(
'id' => '5',
'tag' => 'div5',
'parent' => '0'
),
array
(
'id' => '6',
'tag' => 'div6',
'parent' => '5'
),
array
(
'id' => '7',
'tag' => 'div7',
'parent' => '0'
)
);
The first thing I do is to use a function to turn this array into a multidimensional array by building a tree structure using the parent element of each record as reference:
function buildTree(array $elements, $parentId = 0) {
$branch = array();
foreach ($elements as $element)
{
if ($element['parent'] == $parentId)
{
$children = buildTree($elements, $element['id']);
if ($children)
{
$element['children'] = $children;
}
$branch[] = $element;
}
}
return $branch;
}
$tree_1 = buildTree($array_1);
Once this is done the multidimensional array should look like this:
Array
(
[0] => Array
(
[id] => 1
[name] => div1
[parent] => 0
[children] => Array
(
[0] => Array
(
[id] => 2
[name] => div2
[parent] => 1
[children] => Array
(
[0] => Array
(
[id] => 3
[name] => div3
[parent] => 2
)
[1] => Array
(
[id] => 4
[name] => div4
[parent] => 2
)
)
)
)
)
[1] => Array
(
[id] => 5
[name] => div5
[parent] => 0
[children] => Array
(
[0] => Array
(
[id] => 6
[name] => div6
[parent] => 5
)
)
)
[2] => Array
(
[id] => 7
[name] => div7
[parent] => 0
)
)
The next thing to do is to output the html elements in a nested order. In this example Im using symbolic tag names such as div1, div2, etc; but in reality they could be any html tags like divs, h1, ul,li, form, etc; with their opening and closing tags.
To accomplish this I use the following recursive function, however my problem is that it does not show the html elements in a nested order as they should be.
function recursive($array, $level = 0)
{
foreach($array as $key => $value)
{
if (!is_array($value) && $key == "tag") { echo str_repeat(" ", $level), "[".$value."]", ''; }
//If $value is an array.
if(is_array($value))
{
//We need to loop through it.
recursive($value, $level + 1);
}
else
{
//It is not an array, so print it out.
if ($key == "tag") { echo "[/".$value."]", '<br>'; }
}
}
}
$tree_2 = recursive($tree_1);
echo $tree_2;
This is how it currently outputs the html tags from the array:
[div1][/div1]
[div2][/div2]
[div3][/div3]
[div4][/div4]
[div5][/div5]
[div6][/div6]
[div7][/div7]
And this is how the html tags should be output in reality based on the multidimensional array's nested order (please note how some div tags contain other div tags before their closing element):
[div1]
[div2]
[div3][/div3]
[div4][/div4]
[/div2]
[/div1]
[div5]
[div6][/div6]
[/div5]
[div7][/div7]
How can I get the html tags printed in the right nested order like in the last example? What am I missing? Thanks so much!

Answer 1

The issue is that the key tag is before children in the $tree_1 array.
Whilst I would personally change your data structure around to make it "easier" to use in the recursive function, you can change your recursive function to make it work like this:
function recursive($array, $level = 0)
{
// Check if we are using an associative array or indexed array
if(isset($array['tag'])) {
echo str_repeat(" ", $level), "[" . $array['tag'] . "]", '';
if(isset($array['children'])) {
echo "<br />";
recursive($array['children'], $level + 1);
echo str_repeat(" ", $level), "[/" . $array['tag'] . "]" , '';
} else {
echo "[/" . $array['tag'] . "]";
}
echo "<br />";
} else {
foreach($array as $key => $value)
{
recursive($value, $level + 1);
}
}
}
Add additional line breaks and formatting where required

Answer 2

A rewrite of your function:
function recursive2($array, &$level, $indentClosingTag = true)
{
$level++;
for($i = 0; $i<count($array); $i++) {
$data = $array[$i];
$indent = str_repeat(' ', $level);
echo $indent . "[".$data['tag'].']';
if (isset($data['children'])) {
echo '<br>';
$level++;
recursive2($data['children'], $level, true);
$level--;
} else {
$indentClosingTag = false;
}
echo ($indentClosingTag ? $indent : ''). "[/".$data['tag'].']'.'<br>';
}
$level--;
}
$l = 0;
recursive2($tree_1, $l);