The Imagick::setProgressMonitor() function is an inbuilt function in PHP which is used to set a callback function that will be called during the processing of the Imagick image if something goes wrong. You can use this function to pause a program before proceeding further.
Syntax:
bool Imagick::setProgressMonitor( callable $callback )
Parameters: This function accepts a single parameter $callback which holds the callback function.
Return Value: This function returns TRUE on success.
Exceptions: This function throws ImagickException on error.
Below programs illustrate the Imagick::setProgressMonitor() function in PHP:
Program 1:
<?php   // Create a new Imagick object $imagick = new Imagick();   // Create a image in Imagick object $imagick->newImage(640, 480, "blue");   $status = 'Not cancelled'; $text = '<br>';   // Callback function $callback = function ($offset, $span) use (&$status, $text) {     $status = "Callback is called" . $text;     return false; };   // Set the Progress Monitor $imagick->setProgressMonitor($callback);   try {     // $x and $y are undefined thus a call to     // callback funcction is expected here     $imagick->charcoalImage($x, $y);     echo "Callback function wasn't called."; } catch (\Exception $e) {     echo $status; } ?> |
Output:
Callback is called
Program 2:
<?php   // Create a new Imagick object $imagick = new Imagick();   // Create a image in Imagick object $imagick->newImage(600, 400, "white");   $status = 'Not cancelled'; $text = '<br>';   // Callback function $callback = function ($offset, $span) use (&$status, $text) {     $status = "Callback is called" . $text;     return true; };   // Set the Progress Monitor $imagick->setProgressMonitor($callback);   try {     // $x and $y are defined thus a call to     // callback funcction is expected here     $x = 20;     $y = 5;     $imagick->charcoalImage($x, $y);     echo "Callback function wasn't called."; } catch (\Exception $e) {     echo $status; }   ?> |
Output:
Callback function wasn't called.
Reference: https://www.php.net/manual/en/imagick.setprogressmonitor.php
