Create a tree from a flat array - php

I am having trouble in converting a flat array, e.g. from a DB query, into a tree structure.
I have something like this:
[
[
id => 11,
path => '/11',
label => 'AAA'
],
[
id => 12,
path => '/12',
label => 'BBB'
],
[
id => 21,
path => '/12/21',
label => 'BBBB'
],
[
id => 21,
path => '/12/22',
label => 'CCCCC'
],
]
path points to the hierarchical position inside the tree, defined by the id's. So in the end I have to get something like this:
$tree=[
[
'id' => '11',
'label' => 'AAA'
],
[
'id' => '12',
'label' => 'BBB',
'children' => [
[
'id' => '21',
'label' => 'BBBB'
],
[
'id' => '22',
'label' => 'CCCCC'
]
]
]
];
The depth can be infinite. I would appreciate any solution. Thank you :-)

Thank you all, but I am still stuck :-( Here's my way so far.
First I order the categories by depth & loop them in this order. This way I can be sure that the parent node exists.
public function buildCategoryTree() {
// order by depth
$categoryLevel = [];
foreach (Category::all() as $category) {
$catPathSplitted = array_filter(explode("/", $category->path));
$categoryLevel[count($catPathSplitted)][] = $category;
}
$categoryTree = [];
// now loop each level and create a tree node
foreach ($categoryLevel as $level => $categories) {
foreach ($categories as $category) {
$test = $category->path;
$catPathSplitted = array_filter(explode("/", $category->path));
$categoryTree = $this->addNode($category, $catPathSplitted, $categoryTree, $test);
}
}
}
Then I try to use this recursion, but it only works partially, means I get the child nodes in the hierarchical order,
but the child nodes are also created again on each level. So there's something wrong :-(
private function addNode($cat, $keys, &$tree) {
foreach ($keys as $counter => $id) {
if (!next($keys)) {
if (!isset($tree[$id]['category'])) {
$tree[$id]['category'] = $cat->toArray();
}
} else {
if (!isset($tree[$id]['children'])) {
$tree[$id]['children'] = [];
}
array_shift($keys);
$this->addNode($cat, $keys, $tree[$id]['children'], $test);
}
}
return $tree;
}
Anybody can spot the flaw?

Related

Making changes on a different property of recursive function

I'm currently developing this code that traverse a hierarchical array which should compute the sub-total of a property called cur_compensation. My issue is that the changes I do is not getting save
private function computeSubTotal($hierarchy){
foreach($hierarchy["_children"] as $key => $value){
if(isset($value["_children"]))
{
static::computeSubTotal($value);
}
else{
foreach($hierarchy["_children"] as $employee){
$employee_cur_compensation = $employee["cur_compensation"] ?? 0;
if (!isset($hierarchy["cur_compensation"])) {
$hierarchy["cur_compensation"] = 0;
}
$hierarchy["cur_compensation"] += $employee_cur_compensation;
}
return $hierarchy;
}
}
return $hierarchy;
}
This is the function so what it does it goes to the deepest node, the deepest node is a value that does not have any _children which mean it doesn't have any sub department (the hierarchy is sorted that the sub department are always on top)
The issue I have, once it reaches the bottom it computes the cur_compensation by looping through the employees of that department and adding it on the department "cur_compensation" property.
The issue is that, it doesn't save any of my changes.
So the purpose of the function is to add up the 'cur_compensation' of each employee/sub-department.
For example ->
$rows = array(
array(
'name' => "Main",
'id' => 1,
'parent_id' => 0,
'cur_compensation' => 0,
'_children' => array(
array(
'name' => "Dept A",
'id' => 2,
'parent_id' => 1),
),
array(
'name' => "Dept B",
'id' => 3,
'parent_id' => 1,
'_children' => array(
array(
'name' => "Dept C",
'cur_compensation' => 30000,
'id' => 4,
'parent_id' => 3),
array(
'name' => "Employee C",
'cur_compensation' => 30000,
'id' => 7,
'parent_id' => 3
)
)),
array(
'name' => "Employee A",
'cur_compensation' => 20000,
'id' => 5,
'parent_id' => 1
),
array(
'name' => "Employee B",
'cur_compensation' => 30000,
'id' => 6,
'parent_id' => 1
)
)
)
);
The result I want to get would be:
$rows = array(
array(
'name' => "Main",
'id' => 1,
'parent_id' => 0,
'cur_compensation' => 120000,
'_children' => array(
array(
'name' => "Dept A",
'id' => 2,
'cur_compensation' => 0,
'parent_id' => 1),
),
array(
'name' => "Dept B",
'id' => 3,
'parent_id' => 1,
'cur_compensation' => 60000,
'_children' => array(
array(
'name' => "Dept C",
'cur_compensation' => 30000,
'id' => 4,
'parent_id' => 3),
array(
'name' => "Employee C",
'cur_compensation' => 30000,
'id' => 7,
'parent_id' => 3
)
)),
array(
'name' => "Employee A",
'cur_compensation' => 30000,
'id' => 5,
'parent_id' => 1
),
array(
'name' => "Employee B",
'cur_compensation' => 30000,
'id' => 6,
'parent_id' => 1
)
)
)
);
So you would notice that Main and Dept B got the cur_compensation based on the _children property
There's a few things to make note on here - so I'm going to add comments to your existing code, then provide an example of how you could change it.
(I've formatted the code in each case)
class Example {
// filler code so that we can call
public function process($array){
return $this->computeSubTotal($array);
}
private function computeSubTotal($hierarchy) {
// we're not checking whether "_children" property exists before looping on it
foreach ($hierarchy["_children"] as $key => $value) {
if (isset($value["_children"])) {
// we're calling the method, but not doing anything with the return value.
static::computeSubTotal($value);
// we can set the original array value instead which will provide a modified copy
// this can be resolved by uncommenting the line below
// $hierarchy["_children"][$key] = static::computeSubTotal($value);
// also note that if this "child" doesn't have any *grand*children
// then we won't get an updated value due to how this is structured
// to fix this, you could remove the else wrapping so that the code
// below runs always
} else {
// double looping - we're already looping this array
// this will cause the end value to increase exponentially
foreach ($hierarchy["_children"] as $employee) {
$employee_cur_compensation = $employee["cur_compensation"] ?? 0;
if (!isset($hierarchy["cur_compensation"])) {
$hierarchy["cur_compensation"] = 0;
}
$hierarchy["cur_compensation"] += $employee_cur_compensation;
}
// returning whole array inside the loop is not ideal
// we have already adjusted the main array
// comment out this return to prevent that from happening
return $hierarchy;
}
}
return $hierarchy;
}
}
$example = new Example;
// calling this on $rows won't give us anything back
// since $rows doesn't contain the property "_children"
$rows = $example->process($rows);
// in this case, you would want to process each array result
// only on this primary array
foreach($rows as $index => $value){
$rows[$index] = $example->process($value);
}
echo json_encode($rows, JSON_PRETTY_PRINT);
Taking those comments into account, you would end up with something like this:
private function computeSubTotal($hierarchy) {
// we're not checking whether "_children" property exists before looping on it
foreach ($hierarchy["_children"] as $key => $value) {
if (isset($value["_children"])) {
$hierarchy["_children"][$key] = static::computeSubTotal($value);
}
// double looping - we're already looping this array
// this will cause the end value to increase exponentially
foreach ($hierarchy["_children"] as $employee) {
$employee_cur_compensation = $employee["cur_compensation"] ?? 0;
if (!isset($hierarchy["cur_compensation"])) {
$hierarchy["cur_compensation"] = 0;
}
$hierarchy["cur_compensation"] += $employee_cur_compensation;
}
}
return $hierarchy;
}
That's closer but still, it's not quite correct due to the double looping.
I've made a simpler version that is hopefully easy to follow:
private function computeSubTotal($hierarchy) {
if (!isset($hierarchy["_children"])) {
return $hierarchy;
}
// define this outside the loop for clarity
if (!isset($hierarchy["cur_compensation"])) {
$hierarchy["cur_compensation"] = 0;
}
foreach ($hierarchy["_children"] as $key => $value) {
// don't need to check for "_children" property
// as it's now handled in this function
$updated = static::computeSubTotal($value);
// reference the $updated array to increment
// the "cur_compensation" field
$hierarchy["cur_compensation"] += $updated["cur_compensation"] ?? 0;
// update original array
$hierarchy["_children"][$key] = $updated;
}
return $hierarchy;
}
// call like
foreach ($rows as $index => $value) {
$rows[$index] = static::computeSubTotal($value);
}
You will still need to change how you're passing the $rows variable due to it now containing a "_children" property (as shown in the examples) - either pass each element or add additional logic in that function to handle that.
You need to pass the array as a reference.
https://www.php.net/manual/en/language.references.pass.php
PHP passes the array to the function as a pointer, but when you try to update the array, PHP first makes a full copy of the array and updates the copy instead of the original.
Change your function signature to the following and it should be good.
private function computeSubTotal(&$hierarchy){
P.S. You are calling computeSubTotal statically, but the function is not static itself.

PHP: Translation table to convert mutiple values to another value?

I have a a number of values/IDs that need to be translated to a single ID, what is the recommended method using PHP?
For example, I want IDs 38332, 84371, 37939, 1275 to all translate to ID 1234 and IDs222, 47391, 798 to all translate to ID 1235, etc. .
I'm thinking PHP has something built-in to handle this efficiently?
I'm thinking PHP has something built-in to handle this efficiently?
You can use the standard array as a map, quickly translating one ID to another:
$table[38332]; # int(1234)
depending on how you store your overall translation table, you can create a function that returns the translation from its input:
$table = $translation('I want IDs 38332, 84371, 37939, 1275 to all translate to ID 1234');
$result = $table[1275] ?? null; # int(1234)
Example:
$parseId = static fn(string $i) => (int)trim($i);
$translation = static fn(string $buffer): array
=> preg_match_all('~((?:\d+,\s*)+\d+)\s+to all translate to ID\s*(\d+)~', $buffer, $_, PREG_SET_ORDER)
? array_reduce($_, static fn (array $carry, array $item): array => [
$ids = array_map($parseId, explode(',', $item[1])),
$carry += array_fill_keys($ids, $parseId($item[2])),
$carry,][2], []) : [];
This is pretty easy to accomplish with PHP, here's one way you could do it:
Using this method, you populate the $map array, using the id you want to replace with as the key, and the value being an array of the keys you want to be replaced. It then calculates a simple key => value array based on this to make comparison a lot quicker.
Instead of creating a copy of the data, you could use foreach ($data as &$record)
$data = [
[
'id' => 1,
'foreign_id' => 38332,
'text' => 'a'
],
[
'id' => 2,
'foreign_id' => 84371,
'text' => 'b'
],
[
'id' => 3,
'foreign_id' => 37939,
'text' => 'c'
],
[
'id' => 4,
'foreign_id' => 1275,
'text' => 'd'
],
[
'id' => 5,
'foreign_id' => 222,
'text' => 'e'
],
[
'id' => 5,
'foreign_id' => 47391,
'text' => 'f'
],
[
'id' => 5,
'foreign_id' => 798,
'text' => 'g'
]
];
$map = [
123 => [
38332,
84371,
37939,
1275
],
1235 => [
222,
47391,
798
]
];
// Calculate a map to speed things up later
$map_calc = [];
foreach ($map as $destination_id => $ids) {
foreach ($ids as $id) {
$map_calc[$id] = $destination_id;
}
}
$new_data = [];
foreach ($data as $record) {
if (isset($map_calc[$record['foreign_id']]))
$record['foreign_id'] = $map_calc[$record['foreign_id']];
$new_data[] = $record;
}
var_dump($new_data);

Lower child array keys and combine items

I've one array
$arr = [
'parent' => [
'CHILD' => [
5,6
],
'child' => [
1,2,3,4
],
'Child' => [
5,6,7,8
],
...
]
];
I want to lower the child keys and combine each child having the same case insensitive keys like
$arr = [
'parent' => [
'child' => [
1,2,3,4,5,6,7,8
],
]
];
I've tried with array_change_key_case which always takes the last element and ignores the others.
An array may have multiple children with the same key (with different case)
Try the code below should work:
<?php
$arr = [
'parent' => [
'CHILD' => [
5,6
],
'child' => [
1,2,3,4
],
]
];
$arNew = [];
foreach ($arr as $sParent => $ar) {
foreach ($ar as $sChild => $ar1) {
$sChild = strtolower($sChild);
if (empty($arNew[$sParent][$sChild])) {
$arNew[$sParent][$sChild] = $ar1;
} else {
$arNew[$sParent][$sChild] = array_merge($arNew[$sParent][$sChild], $ar1);
}
}
}
print_r($arNew);

Recursive array parse with nested nodes

I have blackhole in my mind. Im trying to parse array with multilevel nodes. Here's example array:
global $array;
$array = [
'0' => [
'id' => 1,
'parent' => 0,
'name' => 'root 0'
],
'1' => [
'id' => 2,
'parent' => 1,
'name' => 'root 1'
],
'2' => [
'id' => 3,
'parent' => 2,
'name' => 'root 2'
],
'3' => [
'id' => 4,
'parent' => 3,
'name' => 'root 3'
],
'4' => [
'id' => 5,
'parent' => 3,
'name' => 'root 4'
],
'5' => [
'id' => 6,
'parent' => 2,
'name' => 'root 2'
]
];
This should looks after parse like this. Element 3 with parent 3 should have parent 1, because element 2 has parent 2, and its first child.
I trying to get to this using foreach and function:
global $new_array;
$new_array = [];
foreach( $array as $item )
{
if( $item['parent'] == 0 ) {
$new_array[] = $item; // if parent 0 - clone into new array
continue;
}
//echo $item['name'] . PHP_EOL;
$new_array[] = check_parent( $item['parent'] );
}
print_r($new_array);
function check_parent( $parent )
{
//echo '- check for parent of ' . $parent . PHP_EOL;
global $array;
foreach( $array as $item ) {
if( $item['id'] == $parent && $item['parent'] == 0 ) {
//echo '[OK] found root parent id: ' . $item['id'] . PHP_EOL;
$item['parent'] = $item['id'];
return $item;
} else {
return check_parent( $item['id'] );
}
}
}
I'm so confused, but I didn't see where I make a mistake. Maybe someone, can help me to see - where's problem. I working on it few hours and for now, I had blackhole in my mind.
Fiddle:
https://implode.io/jHS8m1
Desired output:
$new_array = [
'0' => [
'id' => 1,
'parent' => 0,
'name' => 'root 0'
],
'1' => [
'id' => 2,
'parent' => 1,
'name' => 'root 1'
],
'2' => [
'id' => 3,
'parent' => 2, // this should have after parse parent 1
'name' => 'root 2'
],
'3' => [
'id' => 4,
'parent' => 3, // this should have after parse parent 1
'name' => 'root 3'
],
'4' => [
'id' => 5,
'parent' => 3, // this should have after parse parent 1
'name' => 'root 4'
],
'5' => [
'id' => 6,
'parent' => 2, // this should have after parse parent 1
'name' => 'root 2'
]
];
Thanks !
Replace the following line in your code
$new_array[] = check_parent( $item['parent'] ); // get child
with below lines of code.
$temp = check_parent( $item['parent'] ); // get child
$item['parent'] = $temp['id'];
$new_array[] = $item;
What is happening is that your check_parent is returning the $item, which happens to be the parent. However, we are only interested in the id of this. So we get the id and replace the parent it in the original $item.
Here is the working Demo
A bit tardy in my response, but I think it is valuable to provide a refined recursive solution.
My snippet:
Modifies by reference
Does not leverage a global variable declaration
Uses just one loop in the custom recursive function.
Code: (Demo)
function replaceParent(&$array, $parent = null) {
foreach ($array as &$item) {
if ($item['id'] == $parent) {
if ($item['parent']) {
return replaceParent($array, $item['parent']);
} else {
return $item['id'];
}
} elseif ($item['parent']) {
$item['parent'] = replaceParent($array, $item['parent']);
}
}
}
replaceParent($array);
var_export($array);
I'll try to explain...
id 1's parent value of 0 fails both primary conditions, so no recursion/processing is performed on that row of data.
id 2's parent value of 1 passes the elseif condition, so the recursive call goes in search of the row with an id of 1. Finding id 1 with a parent value of 0 means the else branch is satisfied and the id value of 1 is passed back through the recursive call to be assigned to $item['parent'] for the original id 2.
To process id 3 (or deeper), multiple recursive calls occur and all conditions play a role in the search and assignment process. First the elseif leads to the first recursion, then the if's if leads to the second recursion, finally the if's else passes the root id's value all the way back to the original grandchild.

Add grouping elements to 2d array and sum values in respective group

I need to add new elemets to my array when a new category value is encountered. When a category value is encountered after the first time, its value1 and value2 values should be added to the first encounter's respective values.
Also, in the result array, I no longer wish to keep the category column. The category-grouping rows should use the category value as its name value.
Sample input:
$datas = [
[
'category' => 'Solution',
'name' => 'Name1',
'value1' => 20,
'value2' => 21
],
[
'category' => 'Solution',
'name' => 'Name2',
'value1' => 30,
'value2' => 31
],
[
'category' => 'Solution1',
'name' => 'Name3',
'value1' => 40,
'value2' => 41
]
];
Desired result:
[
['name' => 'Solution', 'value1' => 50, 'value2' => 52],
['name' => 'Name1', 'value1' => 20, 'value2' => 21],
['name' => 'Name2', 'value1' => 30, 'value2' => 31],
['name' => 'Solution1', 'value1' => 40, 'value2' => 41],
['name' => 'Name3', 'value1' => 40, 'value2' => 41]
]
I tried like this:
private function groupByProductSuperCategory($datas)
{
$return = [];
foreach ($datas as $data) {
$return[$data['category']][$data['name']] = array_sum(array_column('category', $data);
}
return $return;
}
The idea is to calculate first all sum values for by category, and after that just put values from name like another array. Have you an idea of how to do that?
From the posted array... To end in the desired array, there is some tiny fixes to do first. But I assumed it was due to typos while copying here...
So here is the array I started with:
$result = [
0 => [
"category" => 'Solution',
"name" => 'Name1',
"value1" => 20,
"value2" => 21
],
1 => [
"category" => 'Solution',
"name" => 'Name2',
"value1" => 30,
"value2" => 31
],
2 => [
"category" => 'Solution1',
"name" => 'Name3',
"value1" => 40,
"value2" => 41
]
];
Now, that re-organization of the data is a bit more complex than it looks... You need to perform several loops to:
Find distinct "category" names
Perform the summations for each
Add the sum item and the single items
So here is the code I ended with:
function groupByProductSuperCategory($datas){
$category = [];
$return = [];
// Find distinct categories
foreach ($datas as $data) {
if(!in_array($data["category"],$category)){
array_push($category,$data["category"]);
}
}
// For each distinct category, add the sum item and the single items
foreach ($category as $cat) {
// Get the sums
if(!in_array($cat,$return)){
$sum1 = 0;
$sum2 = 0;
foreach ($datas as $data) {
if($data["category"] == $cat){
$sum1 += $data["value1"];
$sum2 += $data["value2"];
}
}
}
// Push the sums in the return array
array_push($return,[
"name" => $cat,
"value1" => $sum1,
"value2" => $sum2,
]);
// Push the single elements
foreach ($datas as $data) {
if($cat == $data["category"]){
array_push($return,[
"name" => $data["name"],
"value1" => $data["value1"],
"value2" => $data["value2"],
]);
}
}
}
return $return;
}
Here is a PHPFiddle to try it out... Hit [F9] to run.
It is much more direct, efficient, and readable to implement a single loop and push reference variables into the result array to allow summing based on shared categories without keeping track of the actual indexes of the category rows.
Code: (Demo)
$result = [];
foreach ($array as $row) {
if (!isset($ref[$row['category']])) {
$ref[$row['category']] = [
'name' => $row['category'],
'value1' => 0,
'value2' => 0
];
$result[] = &$ref[$row['category']];
}
$ref[$row['category']]['value1'] += $row['value1'];
$ref[$row['category']]['value2'] += $row['value2'];
unset($row['category']);
$result[] = $row;
}
var_export($result);

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