PHP | Imagick setProgressMonitor() Function

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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; 
} 
  
?> 