Allow using filters to change the purge url

[stayallive]

This allows the user to do 2 things.

1. Change the /purge suffix that nginx uses by default:

add_filter('rt_nginx_helper_purge_url_path', function () {
    return 'custompurgepath';
});

2. Allow changing the full purge url / domain + suffix at once:

add_filter('rt_nginx_helper_purge_url_base', function () {
    return 'https://custompurgedomain.com/purge';
});

Why both filters? When working with nginx-helper I noticed I often have to change nginx paths algorithm to comply with custom scripting or server changes on our side.
The second filter helps when even the full purge url is different, because of internal networking. Although this happens seldom, the filter helps to mitigate these issues.

Would be great to be able to override it this way instead of hard-coding the changes in 👍

[stayallive]

Rebased for 2.x.

[stayallive]

It would be very appreciated if this can be looked at and/or be rejected if this is not something that you are willing to accept 👍

[chandrapatel]

Hi @stayallive We will discuss internally and will let you know. Thanks for the PR.

[chandrapatel]

@stayallive My apologies to review PR very late.

I have left few comments on PR. Please check and let me know your thought.

Also please update your PR by merging latest changes from master branch to your branch.

Thanks,

[chandrapatel]

@stayallive Thanks for quickly work on the PR.

[stayallive]

No problem happy to see it being accepted, this will make plugin updates in the future a lot easier for us :) Thanks!

[HansVanEijsden]

@stayallive @chandrapatel thank you very much! 👍🏻