Maniphest T301922

Regression: Images do not show when printing article on mobile
Closed, ResolvedPublic2 Estimated Story PointsBUG REPORT
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Assigned To

Authored By

	Jdlrobson
	Feb 16 2022, 9:35 PM

Description

List of steps to reproduce (step by step, including full links if applicable):

On Google Chrome visit any article with lots of images
Click print

What happens?:
Lazy loaded images do not appear in the article

What should have happened instead?:
Lazy images should appear.

Developer notes

Given https://bugs.chromium.org/p/chromium/issues/detail?id=875403#c40 was fixed this, onbeforeprint event blocks the print action. It can thus be fixed with 4 lines of code:

var lazyImageLoader = mw.mobileFrontend.require('mobile.startup').lazyImages.lazyImageLoader;
window.onbeforeprint = function () 
  lazyImageLoader.loadImages( lazyImageLoader.queryPlaceholders( document.getElementById( 'mw-content-text' ) ) );
}

Details

	Project	Branch	Lines +/-	Subject
	mediawiki/extensions/MobileFrontend	master	+9 -4	Use beforeprint event to load all images in print mode

Customize query in gerrit

Related Objects

Mentioned In: T162414: User should be alerted when lazy loaded images haven't loaded in printed version of articles

Event Timeline

Jdlrobson created this task.Feb 16 2022, 9:35 PM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptFeb 16 2022, 9:35 PM

Jdlrobson mentioned this in T162414: User should be alerted when lazy loaded images haven't loaded in printed version of articles.Feb 16 2022, 9:36 PM

Jdlrobson moved this task from Incoming to Needs Prioritization (Product) on the Readers-Web-Backlog board.Feb 17 2022, 8:37 PM

ovasileva renamed this task from Images do not show when printing article on mobile to Regression: Images do not show when printing article on mobile.Feb 28 2022, 10:01 AM

ovasileva triaged this task as Low priority.

ovasileva edited projects, added Readers-Web-Backlog (Kanbanana-FY-2021-22); removed Readers-Web-Backlog.

Jdlrobson moved this task from Needs Analysis to Upcoming on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.Mar 3 2022, 5:29 PM

Jdlrobson raised the priority of this task from Low to Medium.Mar 3 2022, 9:22 PM

LGoto set the point value for this task to 2.Mar 15 2022, 5:24 PM

LGoto moved this task from Upcoming to Ready for Development on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.

I'm surprised this is only a Medium, but then again how many people indeed print from mobile? Do you happen to have numbers on that? (Just curious!) @LGoto

bwang claimed this task.Apr 25 2022, 2:24 PM

bwang moved this task from Ready for Development to Doing on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.

bwang removed bwang as the assignee of this task.Apr 25 2022, 9:33 PM

bwang moved this task from Doing to Code Review on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.

bwang added a subscriber: bwang.

@bwang did you forget to submit the patch?

Jdlrobson moved this task from Code Review to Needs More Work on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.Apr 26 2022, 5:02 PM

Change 785920 had a related patch set uploaded (by Bernard Wang; author: Bernard Wang):

[mediawiki/extensions/MobileFrontend@master] Use beforeprint event to load all images in print mode

https://gerrit.wikimedia.org/r/785920

gerritbot added a project: Patch-For-Review.Apr 26 2022, 5:19 PM

bwang claimed this task.Apr 26 2022, 5:19 PM

bwang reassigned this task from bwang to Jdlrobson.

bwang moved this task from Needs More Work to Code Review on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.

Jdlrobson moved this task from Code Review to Needs More Work on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.Apr 26 2022, 6:42 PM

Change 785920 merged by jenkins-bot:

[mediawiki/extensions/MobileFrontend@master] Use beforeprint event to load all images in print mode

https://gerrit.wikimedia.org/r/785920

ReleaseTaggerBot added a project: MW-1.39-notes (1.39.0-wmf.10; 2022-05-02).Apr 26 2022, 11:00 PM

Maintenance_bot removed a project: Patch-For-Review.Apr 26 2022, 11:30 PM

Jdlrobson reassigned this task from Jdlrobson to Edtadros.Apr 28 2022, 5:03 PM

Jdlrobson moved this task from Needs More Work to QA on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.

Test Result - Beta

Status: ❌ Fail
Environment: beta
OS: macOS Monterey
Browser: Chrome
Device: MBP
Emulated Device:NA

Test Artifact(s):

QA Steps

On Google Chrome visit any article with lots of images
Click print
What happens?:
❌ AC1: Lazy images should appear.

Starting with Page 11, a partial image

Screen Shot 2022-05-03 at 7.16.38 PM.png (956×972 px, 153 KB)

Page 12 an on, only image placeholders exist.

Screen Shot 2022-05-03 at 7.16.50 PM.png (1×2 px, 265 KB)

This is the pdf

Carl Linnaeus - Wikipedia, the free encyclopedia.pdf1 MBDownload

@Jdlrobson, most likely unrelated to the lazy loaded images, in some areas, the text at the bottom of a page will be partially displayed, with the bottom half of the text displayed on the next page.

Screen Shot 2022-05-03 at 7.18.25 PM.png (1×2 px, 193 KB)

@Edtadros looks like you are not testing the mobile site on a mobile device.
The first page should look like:

Screen Shot 2022-05-04 at 2.26.24 PM.png (1×1 px, 170 KB)

Seems to work for me.

Jdlrobson reassigned this task from Jdlrobson to Edtadros.May 5 2022, 5:06 PM

Edtadros moved this task from QA to QA in Prod on the Readers-Web-Backlog (Kanbanana-FY-2021-22) board.May 12 2022, 10:52 PM

@Jdlrobson So I tried the mobile site and it works. But Chrome has a setting that allows you to preload webpages on wifi (Settings->Bandwidth). If I set it to never, even if I see the image in the browser, it doesn't appear in the pdf.

Carl Linnaeus the Younger - Wikipedia.pdf110 KBDownload

. If this is acceptable I will move this to Ready for Signoff.

For the purpose of this ticket, I think that's fine. Does sound like another bug, but probably one that's low priority to fix.

In T301922#7933112, @Edtadros wrote:

@Jdlrobson So I tried the mobile site and it works. But Chrome has a setting that allows you to preload webpages on wifi (Settings->Bandwidth). If I set it to never, even if I see the image in the browser, it doesn't appear in the pdf.
Carl Linnaeus the Younger - Wikipedia.pdf110 KBDownload
. If this is acceptable I will move this to Ready for Signoff.

+1, this seems fine for the purpose of this task. Resolving.

	F35146820: Carl Linnaeus the Younger - Wikipedia.pdf
	May 17 2022, 1:48 AM

	F35103691: Screen Shot 2022-05-04 at 2.26.24 PM.png
	May 4 2022, 9:26 PM

	F35100136: Screen Shot 2022-05-03 at 7.16.38 PM.png
	May 4 2022, 2:22 AM

	F35100152: Screen Shot 2022-05-03 at 7.18.25 PM.png
	May 4 2022, 2:22 AM

	F35100138: Carl Linnaeus - Wikipedia, the free encyclopedia.pdf
	May 4 2022, 2:22 AM

	F35100137: Screen Shot 2022-05-03 at 7.16.50 PM.png
	May 4 2022, 2:22 AM

Regression: Images do not show when printing article on mobileClosed, ResolvedPublic2 Estimated Story PointsBUG REPORTActions