PHP - Array to CSV by Column - php

Question

issue: I have an associative array, where all the keys represent the csv headers and the values in each $key => array.. represent the items in that column.
Research: To my knowledge, fputcsv likes to go in row by row, but this column-based array is making that complicated. I have not found any function out there that accomplishes this.
Example:
Array(
['fruits'] => Array(
[0] => 'apples',
[1] => 'oranges',
[2] => 'bananas'
),
['meats'] => Array(
[0] => 'porkchop',
[1] => 'chicken',
[2] => 'salami',
[3] => 'rabbit'
),
)
Needs to become:
fruits,meats
apples,porkchop
oranges,chicken
bananas,salami
,rabbit
Why it's hard:
You need to know the max number of rows to make blank spots.

Answer 1

I had to write my own function. Thought maybe it might help someone else!
/*
* The array is associative, where the keys are headers
* and the values are the items in that column.
*
* Because the array is by column, this function is probably costly.
* Consider a different layout for your array and use a better function.
*
* #param $array array The array to convert to csv.
* #param $file string of the path to write the file.
* #param $delimeter string a character to act as glue.
* #param $enclosure string a character to wrap around text that contains the delimeter
* #param $escape string a character to escape the enclosure character.
* #return mixed int|boolean result of file_put_contents.
*/
function array_to_csv($array, $file, $delimeter = ',', $enclosure = '"', $escape = '\\'){
$max_rows = get_max_array_values($array);
$row_array = array();
$content = '';
foreach ($array as $header => $values) {
$row_array[0][] = $header;
$count = count($values);
for ($c = 1; $c <= $count; $c++){
$value = $values[$c - 1];
$value = preg_replace('#"#', $escape.'"', $value);
$put_value = (preg_match("#$delimeter#", $value)) ? $enclosure.$value.$enclosure : $value;
$row_array[$c][] = $put_value;
}
// catch extra rows that need to be blank
for (; $c <= $max_rows; $c++) {
$row_array[$c][] = '';
}
}
foreach ($row_array as $cur_row) {
$content .= implode($delimeter,$cur_row)."\n";
}
return file_put_contents($file, $content);
}
And this:
/*
* Get maximum number of values in the entire array.
*/
function get_max_array_values($array){
$max_rows = 0;
foreach ($array as $cur_array) {
$cur_count = count($cur_array);
$max_rows = ($max_rows < $cur_count) ? $cur_count : $max_rows;
}
return $max_rows;
}
New Way (using a class)
I wrote a class for this a while later, which I'll provide for anyone looking for one now:
class CSVService {
protected $csvSyntax;
public function __construct()
{
return $this;
}
public function renderCSV($contents, $filename = 'data.csv')
{
header('Content-type: text/csv');
header('Content-Disposition: attachment; filename="' . $filename . '"');
echo $contents;
}
public function CSVtoArray($filename = '', $delimiter = ',') {
if (!file_exists($filename) || !is_readable($filename)) {
return false;
}
$headers = null;
$data = array();
if (($handle = fopen($filename, 'r')) !== false) {
while (($row = fgetcsv($handle, 0, $delimiter, '"')) !== false) {
if (!$headers) {
$headers = $row;
array_walk($headers, 'trim');
$headers = array_unique($headers);
} else {
for ($i = 0, $j = count($headers); $i < $j; ++$i) {
$row[$i] = trim($row[$i]);
if (empty($row[$i]) && !isset($data[trim($headers[$i])])) {
$data[trim($headers[$i])] = array();
} else if (empty($row[$i])) {
continue;
} else {
$data[trim($headers[$i])][] = stripcslashes($row[$i]);
}
}
}
}
fclose($handle);
}
return $data;
}
protected function getMaxArrayValues($array)
{
return array_reduce($array, function($carry, $item){
return ($carry > $c = count($item)) ? $carry : $c;
}, 0);
}
private function getCSVHeaders($array)
{
return array_reduce(
array_keys($array),
function($carry, $item) {
return $carry . $this->prepareCSVValue($item) . $this->csvSyntax->delimiter;
}, '') . "\n";
}
private function prepareCSVValue($value, $delimiter = ',', $enclosure = '"', $escape = '\\')
{
$valueEscaped = preg_replace('#"#', $escape . '"', $value);
return (preg_match("#$delimiter#", $valueEscaped)) ?
$enclosure . $valueEscaped . $enclosure : $valueEscaped;
}
private function setUpCSVSyntax($delimiter, $enclosure, $escape)
{
$this->csvSyntax = (object) [
'delimiter' => $delimiter,
'enclosure' => $enclosure,
'escape' => $escape,
];
}
private function getCSVRows($array)
{
$n = $this->getMaxArrayValues($array);
$even = array_values(
array_map(function($columnArray) use ($n) {
for ($i = count($columnArray); $i <= $n; $i++) {
$columnArray[] = '';
}
return $columnArray;
}, $array)
);
$rowString = '';
for ($row = 0; $row < $n; $row++) {
for ($col = 0; $col < count($even); $col++) {
$value = $even[$col][$row];
$rowString .=
$this->prepareCSVValue($value) .
$this->csvSyntax->delimiter;
}
$rowString .= "\n";
}
return $rowString;
}
public function arrayToCSV($array, $delimiter = ',', $enclosure = '"', $escape = '\\', $headers = true) {
$this->setUpCSVSyntax($delimiter, $enclosure, $escape);
$headersString = ($headers) ? $this->getCSVHeaders($array) : '';
$rowsString = $this->getCSVRows($array);
return $headersString . $rowsString;
}
}

Answer 2

$data = array(
'fruits' => array(
'apples',
'oranges',
'bananas'
),
'meats' => array(
'porkchop',
'chicken',
'salami',
'rabbit'
),
);
$combined = array(array('fruits', 'meats'));
for($i = 0; $i < max(count($data['fruits']), count($data['meats'])); $i++)
{
$row = array();
$row[] = isset($data['fruits'][$i]) ? $data['fruits'][$i] : '';
$row[] = isset($data['meats'][$i]) ? $data['meats'][$i] : '';
$combined[] = $row;
}
ob_start();
$fp = fopen('php://output', 'w');
foreach($combined as $row)
fputcsv($fp, $row);
fclose($fp);
$data = ob_get_clean();
var_dump($data);
Conversion to csv and parsing of the array can be done in the same loop. Or did you mean that there might be more columns? This code can be easily modified for the general type of the array. Like this, for any number of the columns
$data = array(
'fruits' => array(
'apples',
'oranges',
'bananas'
),
'meats' => array(
'porkchop',
'chicken',
'salami',
'rabbit'
),
);
$heads = array_keys($data);
$maxs = array();
foreach($heads as $head)
$maxs[] = count($data[$head]);
ob_start();
$fp = fopen('php://output', 'w');
fputcsv($fp, $heads);
for($i = 0; $i < max($maxs); $i++)
{
$row = array();
foreach($heads as $head)
$row[] = isset($data[$head][$i]) ? $data[$head][$i] : '';
fputcsv($fp, $row);
}
fclose($fp);
$data = ob_get_clean();
var_dump($data);