This plugin is intended for testing and demonstration purposes. It 'checks' domain ending with .invalid.

It does a pseudo check for all domains with the TLD  .invalid. That domain is intended for testing. The check is executed before and in place of the curl checker.

With the curl checker, none existing doamains would return an SSL or DNS error, depending on your system.

This checker can return a specific HTTP code using specialy crafter domain names. Any domain ending in a three-digit code will return that code as HTTP response code. This 200.invalid will return HTTP code 200, 404.invalid a not found.

For redirect codes (300 to 399) a dummy redirect (final URL)  will be set appending  '-pseude-redirect-' . <HTTP-code> to the URL.

Domains without a code will return a 206 code (partial content).

It is also a good starting point to create a custom checker, as it has the three required functions:

• onBlcCheckerRequest'  
• canCheckLink
• checkLink