Add function to replace URL

[ouun]

Dear KeyCDN-Team,
thank you very much for this amazing plugin. The latest updates are amazing!
However a simple helper function to replace a URL with the CDN URL would be awesome. Let's say for some reason I need to get the CDN URL of a path which does not contain one of the "CDN Inclusions". E.g. a hook for get_template_path() using the rewrite engine will not change the URL.

I have a workaround in place that adds and removes a fake JS file so that CDN Rewrite Engine processes it. However e.g. a simple get_cdn_url($url) function that uses the rewrite engine for whatever is passed. That would be awesome and replaces this:

add_filter('get_template_path', function ($url) {
            $workaround = '/workaround.js';

            // Workaround: Add & remove JS appendix to get recognized by Cache Enabler Rewrite Engine
            return str_replace($workaround, '', CDN_Enabler_Engine::rewriter($url . $workaround));
}

[coreykn]

You're welcome! We're really happy to hear that. Hmm, currently the regular expression used in CDN_Enabler_Engine::rewriter() relies on an extension to ensure correct matches are made.

To get a better idea of what you're trying to accomplish, can you please share an example of the value(s) that you're wanting to rewrite? For example, the value of the $url variable.

[ouun]

Hi @coreykn,
thanks a lot for getting back to me. In my scenario I need to filter a base URL that my theme uses in JS to async load JS and CSS. There is one main.js with a loader script that refences various futher JS & CSS files. So only the base URL without filename is passed to main.js, therefore it is not recognized by CDN_Enabler_Engine::rewriter() and the theme assets are not loaded from CDN.

Example:
WP passes https://example.com/app/themes/mytheme/dist/ as base URL to main.js. In main.js the files js/1a2.js and style/2b3.css are referenced by combining the base URL and filename to https://example.com/app/themes/mytheme/dist/js/1a2.js and https://example.com/app/themes/mytheme/dist/style/1a2.css.

Both files will not get loaded from CDN as the files never go through the PHP filters as main.js is running client side.

Solution:
Lets say there is a filter to adjust the base URL https://example.com/app/themes/mytheme/dist/ to whatever is my CDN URL from Cache Enabler settings. So I just pass https://example.com/app/themes/mytheme/dist/ to CDN_Enabler_Engine::rewriter() and receive back https://myCDN.com/app/themes/mytheme/dist/.

I already had various other use cases where I just wanted to get a URL transformed into CDN URL without a file appendix. That is why I used the workaround above in which I temporary add a filename to the URL, pass it to CDN_Enabler_Engine::rewriter() to get processed and then remove the filename again from the returned value.

I hope that makes it more clear. :)

Kind regards,

Philipp

[coreykn]

Thank you for the detailed reply, I really appreciate it. That definitely makes it clear. 🙂

I do believe having this capability would be beneficial and I would like to bring it to CDN Enabler. I have other tasks that are taking priority at the moment, which means I will need to come back to this at a later point of time. A separate method could easily be added to support this, or even updating CDN_Enabler_Engine::rewrite_url() itself to allow this. However, my goal is to keep all rewriting in CDN_Enabler_Engine::rewriter() due to all the handling built around this method. When I get back to it I'll have to see if that will be the best way.

In the meantime you can continue to use your workaround or come up with a custom function. For example, CDN_Enabler_Engine::$settings['cdn_hostname'] is available to replace a specific value.

[mattneal-stafflink]

Just wanted to bump this request, and say that I'd love to use it as well. I'm currently using the WordPress API to display posts, and I'm getting a meta field called 'property_images', and as you would expect, it returns the actual URL, and I pass that to the front end. Being able to feed that string/array to a function like @ouun has suggested would be perfect for a situation like this.

For the moment, I can simply create a function that changes the URL's before I pass them to the front end, but I would assume if we use the CDN Enabler engine, that would be a much more comprehensive way to do it. My way is quite hacky.

[mattneal-stafflink]

Actually, I'm not sure if this is 100% how it should be done, but the code I was working with can access the CDN Enabler Engine class, so I can just do this:

if( class_exists( 'CDN_Enabler_Engine' ) ) {
    $image = CDN_Enabler_Engine::rewriter( $image );
}

This works perfectly. If you can think of why this is a terrible idea, I'd love to hear it so I don't break my production sites lol.