Building paths from multidimensional array in PHP - php

Question

I have an array such as:
$tree = array(
'folder_1' => array(
'folder_1_1',
'folder_1_2' => array(
'folder_1_2_1',
'folder_1_2_2'
),
'folder_1_3'
),
'folder_2' => array(
'folder_2_1' => array(
'folder_2_1_1' => array(
'folder_2_1_1_1',
'folder_2_1_1_2'
)
),
)
);
And I'm trying to build an array of paths:
$paths = array(
'folder_1',
'folder_1/folder_1_1',
'folder_1/folder_1_2',
'folder_1/folder_1_2/folder_1_2_1',
'folder_1/folder_1_2/folder_1_2_2',
'folder_2',
'folder_2/folder_2_1',
...
);
I can't seem to find a way to achieve this. The problem I encounter is that folder names can be array keys, but also array elements.
This is what I have done so far, but I'm not near a solution...
$paths = transform_tree_to_paths($trees);
function transform_tree_to_paths($trees, $current_path = '', $paths = array())
{
if (is_array($trees)) {
foreach ($trees as $tree => $children) {
$current_path .= $tree . '/';
return transform_tree_to_paths($children, $current_path, $paths);
}
$paths[] = $current_path;
$current_path = '';
} else {
$paths[] = $trees;
}
return $paths;
}

Answer 1

How about something like this?
function gen_path($tree, $parent=null) {
$paths = array();
//add trailing slash to parent if it is not null
if($parent !== null) {
$parent = $parent.'/';
}
//loop through the tree array
foreach($tree as $k => $v) {
if(is_array($v)) {
$currentPath = $parent.$k;
$paths[] = $currentPath;
$paths = array_merge($paths, gen_path($v, $currentPath));
} else {
$paths[] = $parent.$v;
}
}
return $paths;
}
You were headed in the right direction, but missed the mark a bit. The return statement before the recursive function call in your function caused everything after the foreach loop to never be called.

Answer 2

Here's another solution, utilizing RecursiveArrayIterator and RecursiveIteratorIterator:
function generatePaths( array $tree ) {
$result = array();
$currentPath = array();
$rii = new RecursiveIteratorIterator( new RecursiveArrayIterator( $tree ), RecursiveIteratorIterator::SELF_FIRST );
foreach( $rii as $key => $value ) {
if( ( $currentDepth = $rii->getDepth() ) < count( $currentPath ) ) {
array_splice( $currentPath, $currentDepth );
}
$currentPath[] = is_array( $value ) ? $key : $value;
$result[] = implode( '/', $currentPath );
}
return $result;
}
PS.: Baconics' solution appears to be about twice as fast as mine, though.