PHP Download Button Not Working Generate Empty File - php

Question

I have two button in the form, one is to submit and second button download the output shown in the textarea.
The submit works fine but download button create empty file and does not write data of output text area.
Here is code:
<?php
error_reporting(0);
$mytext = "";
$txt = preg_replace('/\n+/', "\n", trim($_POST['inputtext']));
$text = explode("\n", $txt);
$output = array();
if(isset($_POST["submit"]))
{
for($i=0;$i<count($text);$i++)
{
$output[] .= trim($text[$i]) . ' Text added with output'.PHP_EOL;
}
}
if(isset($_POST["download"]) ) {
$handle = fopen("file.txt", "w");
fwrite($handle, implode($output));
fclose($handle);
header('Content-type: application/octet-stream');
header('Content-Disposition: attachment;filename='.basename('file.txt'));
header('Expires: 0');
ob_end_clean();
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize('file.txt'));
readfile('file.txt');
exit;
}
?>
<form method="POST" action="test.php">
<textarea name="inputtext" rows="10" cols="100" placeholder="Enter Any Text!" required><?php if(!empty($_POST["inputtext"])) { echo $_POST["inputtext"]; } ?></textarea>
<br><br>
<input type="submit" name="submit" value="Do it!">
<br><br>
<p>Output goes here. </p><textarea name="oputputtext" rows="10" cols="100" ><?php echo implode($output);?></textarea>
<input type="submit" name="download" value="Download Output">
</form>

Answer 1

You have to generate the output also if downloading (unless you take it from the second textarea), so use if(isset($_POST["submit"]) || isset($_POST["download"]) ) in the test, instead of only if(isset($_POST["submit"]))
The final code would look like this:
<?php
error_reporting(0);
$mytext = "";
$txt = preg_replace('/\n+/', "\n", trim($_POST['inputtext']));
$text = explode("\n", $txt);
$output = array();
/* CHANGED HERE */
if(isset($_POST["submit"]) || isset($_POST["download"]) ) {
for($i=0;$i<count($text);$i++) {
$output[] .= trim($text[$i]) . ' Text added with output'.PHP_EOL;
}
}
if(isset($_POST["download"]) ) {
$handle = fopen("file.txt", "w");
fwrite($handle, implode("\r",$output));
fclose($handle);
header('Content-type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename('file.txt'));
header('Expires: 0');
ob_end_clean();
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize('file.txt'));
readfile('file.txt');
exit;
}
?>
<form method="POST" action="test.php">
<textarea name="inputtext" rows="10" cols="100" placeholder="Enter Any Text!" required><?php if(!empty($_POST["inputtext"])) { echo $_POST["inputtext"]; } ?></textarea>
<br><br>
<input type="submit" name="submit" value="Do it!">
<br><br>
<p>Output goes here. </p>
<textarea name="oputputtext" rows="10" cols="100" ><?php echo implode($output);?></textarea>
<input type="submit" name="download" value="Download Output">
</form>