wp-media / imagify-plugin

Speed up your website with lighter images without losing quality.
https://imagify.io
73 stars 26 forks source link

Update callback priority on template_redirect for picture display #891

Closed remyperona closed 1 month ago

remyperona commented 3 months ago

Context Related to https://github.com/wp-media/wp-rocket/issues/6786

WP Rocket Lazyload exclusion is not working correctly when excluded pattern is part of a picture element created by the picture rewriting feature of Imagify.

Expected beavhior Lazyload exclusion should work as expected

Additional information So I believe I found what was happening with the next-gen issue. we have 2 callbacks on template_redirect:

So we should expect imagify to be finished first, and WP Rocket after. BUT, both callbacks have an ob_start() call, and when multiple are called, they become nested until the buffering stops:

When output buffering ends (on shutdown action of WP), lower level content is passed to upper, so the order becomes WP Rocket optimizations first, then Imagify second, and HTML is output. While callback priority is as expected, the output buffering works in the opposite order.

To verify, I tested by changing the priority of Imagify callback to 10, reverting both orders, and it works as expected, the picture element is applied first in the HTML, and then lazyload exclusion works as needed.

wordpressfan commented 3 months ago

I can confirm that the provided fix is working from my side, I was trying to find why we used to use this priority -1000 and I found that we did that here:

https://github.com/wp-media/imagify-plugin/pull/383 to fix this issue: https://github.com/wp-media/imagify-plugin/issues/368

So I believe we need to validate that issue and make sure that CDN is working properly with such change.

johan-las commented 3 months ago

New related case: https://secure.helpscout.net/conversation/2676079310/507022?folderId=8127840

wordpressfan commented 3 months ago

I tested when using RocketCDN here: https://new.rocketlabsqa.ovh/next-gen-image/ and all good I believe, so we are fine here.

MathieuLamiot commented 3 months ago

Blocked pending product decision on the feedbacks from QA.

MathieuLamiot commented 3 months ago

Feedbacks from QA on the PR need to be investigated then handled. this is not a priority compared to 3.17 os moving this back to Needs Grooming and outside of the sprint.

alfonso100 commented 2 months ago

related https://secure.helpscout.net/conversation/2701935175/511314/#thread-8146661296

camilamadronero commented 1 month ago

new case: https://secure.helpscout.net/conversation/2715278553/513749?viewId=2675957

MathieuLamiot commented 1 month ago

@Khadreal Do you have an update on this grooming? Thanks!

Khadreal commented 1 month ago

Would revert later today, the LL is not excluded if it's picture display and cdn is on.

@Khadreal Do you have an update on this grooming? Thanks!

Khadreal commented 1 month ago

After debugging with @wordpressfan, we discovered that the issue is related to the speed between RocketCDN and WPR. We’ll be submitting another PR to WPR to address this.

During lazy loading, the URL in the <source> element of the <picture> tag hasn't been correctly updated. However, the src for images excluded from AboveTheFold optimization has already been rewritten. Because of this, the logic here to check if the image should be excluded will consistently fail.

String: <picture decoding="async" data-id="88132" class="wp-image-88132">
<source type="image/avif" srcset="https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1067x800.jpg.avif 1067w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-533x400.jpg.avif 533w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-768x576.jpg.avif 768w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1536x1152.jpg.avif 1536w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-2048x1536.jpg.avif 2048w" sizes="(max-width: 1067px) 100vw, 1067px"/>
<source type="image/webp" srcset="https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1067x800.jpg.webp 1067w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-533x400.jpg.webp 533w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-768x576.jpg.webp 768w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1536x1152.jpg.webp 1536w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-2048x1536.jpg.webp 2048w" sizes="(max-width: 1067px) 100vw, 1067px"/>
<img decoding="async" width="1067" height="800" data-id="88132" src="https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1067x800.jpg" alt="" srcset="https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1067x800.jpg 1067w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-533x400.jpg 533w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-768x576.jpg 768w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-1536x1152.jpg 1536w, https://new.rocketlabsqa.ovh/wp-content/uploads/2024/08/marchlarge1-2048x1536.jpg 2048w" sizes="(max-width: 1067px) 100vw, 1067px"/>
</picture> 
Excluded image : wp-content/uploads/2024/08/7sk3pi.jpg.avif 500w, https://9a2073a2.rocketcdn.me/wp-content/uploads/2024/08/7sk3pi-400x400.jpg.avif 400w, https://9a2073a2.rocketcdn.me/wp-content/uploads/2024/08/7sk3pi-280x280.jpg.avif 280w
MathieuLamiot commented 1 month ago

Thanks @Khadreal. Assigning to you and moving to In Progress then.

remyperona commented 1 month ago

is there some way I can help with that?

Khadreal commented 1 month ago

I think the challenge here is with the rocketcdn plugin as a standalone, it's using template_redirect which is conflicting with imagify process. For CDN within wpr, changing the priority for rocket_buffer solves the issue.

I'm thinking of one of the solution -- If you're using rocketcdn plugin and wpr is installed, we bail out early and use the cdn within the plugin(there might be some drawback here) -- Consider using rocket_buffer for rocketcdn plugin instead of the template_redirect Please let me know what you think ?

remyperona commented 1 month ago

We can update the priority used in the RocketCDN plugin too, to make sure everything executes in the order we need

Khadreal commented 1 month ago

The priority is in the right order though in RocketCDN

Khadreal commented 1 month ago

@wp-media/qa-team to test the PRs for this issue please follow this RocketCDN + Imagify

WPRocket + Imagify To test with WPR cdn Make sure you're on this branch fix/891-template-redirect-priority for imagify and on this branch fix/891-template-redirect-priority for WPR and follow the same step as shared above.

Mai-Saad commented 1 month ago

2nd round of tests using WPR and imagify in sheet 2 here https://docs.google.com/spreadsheets/d/1YpkRpc_PkcszOezpkIooWC6hIWnkIWnXITvoHNjEjIo/edit?gid=1626911531#gid=1626911531 , waiting PO decision if we need to do further fix here https://wp-media.slack.com/archives/CUKB44GNN/p1728893947213469

Mai-Saad commented 1 month ago

as per discussion with @piotrbak we are good to proceed with the current state and for C7 , clear priority elements will fix that