Unexpected behavior in recursive function - php

Question

The task is to remove arrays recursively that have error => 4 (i.e key with that value) with their keys, and then turn remained arrays into objects.
The structure of incoming array might be different. Two examples of it are this ones:
// Example input #1
$ex_input_1 = array(
'files' => array(
0 => array(
'name' => 'file.jpg',
'size' => '244235',
'tmp_name' => '/usr/tmp/24ffds.tmp',
'error' => 0
),
1 => array(
'name' => '',
'size' => '',
'tmp_name' => '',
'error' => 4
)
),
'cover' => array(
'name' => '',
'size' => '',
'tmp_name' => '',
'error' => 4
),
'document' => array(
'name' => 'file.doc',
'size' => '244235',
'tmp_name' => '/usr/tmp/24ffds.tmp',
'error' => 0
)
);
// Example input #2
$ex_input_2 = array(
0 => array(
'name' => 'file.jpg',
'size' => '244235',
'tmp_name' => '/usr/tmp/24ffds.tmp',
'error' => 0
),
1 => array(
'name' => '',
'size' => '',
'tmp_name' => '',
'error' => 4
)
);
i.e an array that have name, size, tmp_name, error keys might be at any level down.
What I tried:
Tried to write a simple handler with two methods, where the first one is recursive handler and the second one is hydrator method. Here's it with relevant parts:
<?php
class FileInputParser
{
/**
* Recursively hydrate array entires skipping empty files
*
* #param array $files
* #return array
*/
public function hydrateAll(array $files)
{
foreach ($files as $name => $file) {
if (!is_array($file)) {
continue;
}
foreach ($file as $key => $value) {
if (is_array($value)) {
// Recursise call
$files[$name] = $this->hydrateAll($files[$name]);
} else {
$target = $this->hydrateSingle($file);
// Here I'm EXPLICTLY asking not to push an array, which has error = 4
// But it pushes anyway!!
if ($target !== false) {
unset($files[$name]);
}
}
}
}
return $files;
}
/**
* Hydrates a single file item
*
* #param array $file
* #return mixed
*/
private function hydrateSingle(array $file)
{
$entity = new stdclass;
$entity->name = $file['name'];
$entity->tmp_name = $file['tmp_name'];
$entity->error = $file['error'];
$entity->size = $file['size'];
if ($entity->error != 4) {
return $entity;
} else {
// Returning false to indicate, that this one should not be pushed in output
return false;
}
}
}
The problem
While at first glance it works, the problem is that, when I'm asking explicitly not to add an array that has error = 4 to output, but it continues to add!
You can run aforementioned code with input examples:
<?php
$parser = new FileInputParser();
$output = $parser->hydrateAll($ex_input_1);
echo '<pre>', print_r($output, true);
to see that it also returns unwanted arrays (i.e the ones that have error = 4).
The question
Why it continues to add arrays to output that have error = 4 ?
if you have a better idea on handling this, I'd love to hear it.

Answer 1

Here's a recursive function that will do the filtering you want. When it reaches the bottom of the tree, it checks for error == 4 and if it is, returns an empty array, otherwise it returns the current array. At the next level down any empty values returned are removed by array_filter:
function array_filter_recursive($array) {
if (isset($array['error'])) {
// bottom of tree
return $array['error'] == 4 ? array() : $array;
}
foreach ($array as $key => $value) {
$array[$key] = array_filter_recursive($value);
}
// remove any empty values
return array_filter($array);
}
Output from filtering your two input arrays:
Array (
[files] => Array (
[0] => Array (
[name] => file.jpg
[size] => 244235
[tmp_name] => /usr/tmp/24ffds.tmp
[error] => 0
)
)
[document] => Array (
[name] => file.doc
[size] => 244235
[tmp_name] => /usr/tmp/24ffds.tmp
[error] => 0
)
)
Array (
[0] => Array (
[name] => file.jpg
[size] => 244235
[tmp_name] => /usr/tmp/24ffds.tmp
[error] => 0
)
)
Demo on 3v4l.org