Wordpress DownloadProxy Class

Class DownloadProxy

• Class name: DownloadProxy
• Namespace: set yourself if required

This DownloadProxy Class allows you to proxy your custom attachments though this class and do further check if the current user is allowed to download this file.

Links like /wp-upload/year/month/file.pdf can replaced with a proxy link. This class provides a codebase and can be modificated.

It does:

• provides getPublicDownloadLink
• provides canDownloadFile which can be implemented or extended
• register /download/$attachmentid/$filename route
• handles GET request for that /download/ route
• display error message if canDownloadFile returns false

Example use

please take care of autoloading, require and class structure yourself. DownloadProxy class should instanced in every page for example with function.php to keep /download/ route working

functions.php

$downloadProxy = new DownloadProxy();

Template:

<a href="<?php echo $downloadProxy->getPublicDownloadLink($attachmentID); ?>
  <i class="fa fa-download"></i>
</a>

Public Methods

getPublicDownloadLink

boolean|string DownloadProxy::getPublicDownloadLink($attachmentID)

returns proxy download url for an attachmentID which can be used as public link

• Visibility: public

Arguments

• $attachmentID INT - ID of an Wordpress attachment

canDownloadFile

boolean DownloadProxy::canDownloadFile($attachmentID, $parameterFileName)

public function to check if current user can download an specific file. Please customise this function for your individual requirements. As example check we use a comparing between the real file name and the file which was expected. With that check, it's not possible to download all files /download/1, download/2 without knowing the filename

• Visibility: public

Arguments

• $attachmentID INT
• $parameterFileName STRING file name expected from filesystem

Internal Methods

downloadFile

mixed DownloadProxy::downloadFile($wp_query)

Checks for set 'action' param set to 'downloadProxy'.

Loads attachment id and filename from params in uri after that checks permission and reads file to browser to enable download. Function called by wordpress filter parse_query. No need for manual call.

• Visibility: public

Arguments

• $wp_query WP_Query Object - current query object

getRawFile

mixed DownloadProxy::getRawFile($attachmentID)

starts browser download of attachment called by downloadFile after permission check

• Visibility: protected

Arguments

• $attachmentID INT