Create CSV with dynamic grouped headers in PHP from array - php

Question

Could someone please assist in achieving that follow tasks please?
How to create a CSV export from a multidimensional array, but to have dynamic grouped column headings
Array (
[0] => Array ( [months] => 06/2020 [hours] => 202 [skill] => 5 )
[1] => Array ( [months] => 06/2020 [hours] => 563.5 [skill] => 6 )
[2] => Array ( [months] => 07/2020 [hours] => 140.5 [skill] => 6 )
[3] => Array ( [months] => 07/2020 [hours] => 522.5 [skill] => 5 )
)
So the output on the CSV would be like
+----------------------------+------------+--------+
| | Skill 6 |Skill 5 |
+----------------------------+------------+--------+
| 06/2020 | 563.5 | 202 |
+----------------------------+------------+--------+
| 07/2020 | 140.5 | 522.5 |
+----------------------------+------------+--------+
Added CSV output I have so far
Current CSV Element of the code
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename=result_file.csv");
header("Pragma: no-cache");
header("Expires: 0");
// Building $data_array from DB
foreach ($data_array as $subarray) {
$tempKey = $subarray['skill'].$subarray['months'];
$subarray['hours'] = str_replace(',', '', $subarray['hours']);
if (isset($result[$tempKey])) {
$result[$tempKey]['hours'] += $subarray['hours'];
} else {
$result[$tempKey] = $subarray;
}
}
// CSV Output
outputCSV($result);
function outputCSV($result) {
$output = fopen("php://output", "w");
foreach ($result as $row) {
fputcsv($output, $row);
}
fclose($output);
}
any help would be greatly appreciated, TIA
Question edited

Answer 1

Pretty sure if I thought about this for a bit I could improve it but it seems like it gets the right answer
$in = [
[ 'months' => '06/2020', 'hours' => 202, 'skill' => 5 ],
[ 'months' => '06/2020', 'hours' => 563.5, 'skill' => 6 ],
[ 'months' => '07/2020', 'hours' => 140.5, 'skill' => 6 ],
[ 'months' => '07/2020', 'hours' => 522.5, 'skill' => 5 ]
];
$firstTitle = 'Month';
$months = [];
$skills = [$firstTitle=>1];
// make an array keyed on the date
foreach ( $in as $t) {
$months[$t['months']]['skill'.$t['skill']] = $t['hours'];
$skills['skill'.$t['skill']] = 1;
}
// sort skills into assending order
ksort($skills);
// open a file
$xl = fopen('excelfile.csv', 'w');
// echo title line from the skills array
fputcsv($xl, array_keys($skills));
// build csv line with skills in the correct order
foreach ($months as $date => $m){
// build array in correct sorted order
$t = [];
$t[] = $date;
foreach ($skills as $skill => $x) {
if ( $skill != $firstTitle) $t[] = $m[$skill];
}
fputcsv($xl,$t);
}
RESULT
Month,skill5,skill6
06/2020,202,563.5
07/2020,522.5,140.5

Answer 2

You're basically just aggregating the skill values by month and then outputting those aggregated values. This is not difficult, but you've got to be clear about what you're doing. One common reason I see new players get confused is that they're trying to use the most compact code possible, which makes it hard to keep track of what's happening. Be verbose, name things clearly, and comment your code relentlessly. You'll have a much easier time seeing why something isn't working, and your code will be much more maintainable. Write your code like someone else is going to be maintaining it. That someone else may be you in five years.
<?php
$dataArray = [
['months' => '06/2020', 'hours' => '202', 'skill' => '5'],
['months' => '06/2020', 'hours' => '563.5', 'skill' => '6'],
['months' => '06/2020', 'hours' => '303.7', 'skill' => '6'],
['months' => '08/2020', 'hours' => '123.5', 'skill' => '8'],
['months' => '07/2020', 'hours' => '140.5', 'skill' => '6'],
['months' => '07/2020', 'hours' => '522.5', 'skill' => '5'],
['months' => '08/2020', 'hours' => '123.5', 'skill' => '6']
];
/*
* Break out your formatting into functions so that it's re-usable and doesn't clutter up your logic
*/
function formatHours($hourString)
{
$hourString = str_replace(',', '', $hourString);
return floatval($hourString);
}
function buildSkillKey($skillValue)
{
return 'Skill '.$skillValue;
}
// Set up buffers for our skills and month values
$skills = [];
$buffer = [];
foreach($dataArray as $currRow)
{
//Format the hour value
$currHours = formatHours($currRow['hours']);
//Create key for the skill.
$skillKey = buildSkillKey($currRow['skill']);
/*
* Add the skill to the skill buffer. Using the value as the key is an easy way to both prevent duplicates
* without having to implement any logic, and have automatic alpha sorting
*/
$skills[$skillKey] = $skillKey;
// Set up an array for the month value if we don't have one already
if(!array_key_exists($currRow['months'], $buffer))
{
$buffer[$currRow['months']] = [];
}
/*
* If you don't have multiple month/skill entries that you need to aggregate, remove this condition
* and simply set the value in the buffer rather than adding with +=
*/
if(!array_key_exists($skillKey, $buffer[$currRow['months']]))
{
$buffer[$currRow['months']][$skillKey] = 0;
}
$buffer[$currRow['months']][$skillKey] += $currHours;
}
// Define a string for the months column header
$monthColumnTitle = '';
// Create the header row by combining the month header and the skills buffer
$header = array_merge([$monthColumnTitle], $skills);
// Open an output handle and send the header
$outputHandle = fopen("skills.csv", "w");
fputcsv($outputHandle, $header);
// Spin through the buffer
foreach($buffer as $currMonth=>$currSkillValues)
{
// Initialize an output array with the month in the first position
$currOutput = [$currMonth];
// Iterate through the skill buffer
foreach($skills as $currSkillLabel)
{
/*
* If we have a value for this skill, add it to the output row, otherwise insert an empty string.
*
* If you prefer to send zeros rather than empty strings, you can just set the field value to
* $currSkillValues[$currSkillLabel], since we initialized all skills with zeroes when building
* the value buffer.
*/
$currFieldValue = (!empty($currSkillValues[$currSkillLabel])) ? $currSkillValues[$currSkillLabel]:'';
$currOutput[] = $currFieldValue;
}
// Send the row
fputcsv($outputHandle, $currOutput);
}