Directories for temporary files

mPDF is pre-configured to use <path to mpdf>/tmp as a directory to write temporary files (mainly for images and fonts).

It is advised to set custom temporary directory as the default temporary directory is in composer vendor directory. Permissions must be set for read/write access for the specified path.

If you wish to use a different directory for temporary files, you should define tempDir key in constructor $config parameter.

Since 8.0.9, mPDF will create a subdirectory to store cache files to not interfere with other temporary files (eg. when sys_get_temp_dir() is used for tempDir)

mPDF autocleans its temp directory from potentialy stale files. By default it removes files older than 1 hour. Since 8.0.9, this can be changed by cacheCleanupInterval config variable set either to number of seconds of stale files age, or false to turn the cleanup off.

<?php

// Require composer autoload
require_once __DIR__ . '/vendor/autoload.php';

$mpdf = new \Mpdf\Mpdf(['tempDir' => __DIR__ . '/custom/temp/dir/path']);

For mPDF <7.0, there are constants _MPDF_TEMP_PATH and _MPDF_TTFONTDATAPATH which can be used to alter default temporary files directories.

Images

Up to version 6.x, Images will still be processed without write permissions to the temp directory, but at considerable cost in processing time and memory usage.

Fonts

Up to version 6.x, fonts can still be used and embedded without write permissions to this directory, but at some cost in processing time and memory usage.