[EPIC] Core should provide inline diffs as well as side by side (Move InlineDifferenceEngine into core / remove MobileDiff)
Open, MediumPublic
Actions

Assigned To

None

Authored By

	Jdlrobson
	Oct 30 2015, 7:45 PM

Description

Background

MobileFrontend provides an InlineDifferenceEngine which rather than displaying the diff in a 2 column layout displays it in a single column (e.g. unified). This seems like it would be useful for core as most websites these days offer unified as well as 2 column layout diffs and the former is extremely useful on mobile.

The Mobilefrontend diff has been a nuisance point in recent changes to revisions (e.g. Multi content revisions) and it would be helpful to make unified diffs a first class citizen in some form. This inconsistency causes confusion due to the completely different implementations: (see T123413)

Proposal

Put the MobileDiff code in core with any necessary modifications (The code for includes/diff/DifferenceEngine.php is pretty messy and is likely to need heavy refactoring to achieve this).

Update core diff page to allow switching to the inline diff and surface this in the desktop UI. (T240608)

Remove the code in MobileFrontend that has been upstreamed to core. (T240622)

It should be possible that https://en.wikipedia.org/w/index.php?title=San_Francisco&type=revision&diff=687927333&oldid=687926997&diffonly=1&useskin=minerva&diff-type=inline&diffmode=source renders a single column diff and replicates the functionality of https://en.m.wikipedia.org/wiki/Special:MobileDiff/687926997 (T240624)

Update MobileFrontend to use this link and retire Special:MobileDiff page (https://gerrit.wikimedia.org/r/c/mediawiki/extensions/MobileFrontend/+/547263/)

Consider hiding or surfacing side by side diffs in mobile

Questions

What other solutions provide inline diffs? Is MobileFrontend implementation the best one?
What refactors are necessary in core / to mobile code to support such a change if the mobile implementation is favoured.

Details

Project	Branch	Lines +/-	Subject
mediawiki/skins/MinervaNeue	master	+344 -0	Style the desktop diff page of Minerva to look like Special:MobileDiff
mediawiki/core	master	+54 -35	Separate header generation from diff generation
mediawiki/core	master	+111 -8	Inline diffs upstreamed from MobileFrontend to core.
mediawiki/extensions/MobileFrontend	master	+19 -3	Namespace InlineDifferenceEngine
mediawiki/core	master	+84 -30	Permissioning refactor of DifferenceEngine
mediawiki/extensions/MobileFrontend	master	+1 -182	Mobile diffs should use OneColumnDifferenceEngine in core

Customize query in gerrit

Related Objects
Search...

Status	Subtype	Assigned	Task
Declined		dchen	T118706 Conduct heuristic evaluation of image upload and insert flow in VisualEditor
Open		None	T115858 Design improvements for mw.ForeignStructuredUpload.BookletLayout
Open		None	T115865 Insert image in content immediately after it's uploaded, skipping the "General settings" step
Duplicate		None	T115864 Figure out if the description of the image can be used as the caption on-wiki
Open	Feature	None	T53032 When inserting an image, set its caption by default to be the Commons image description
Open	BUG REPORT	None	T12863 Links on commons upload summaries do not link to commons
Open		None	T5498 Image history is confusing
Stalled		None	T96384 Integrate file revisions with description page history
Open	Feature	None	T39534 Wikimedia Commons should support searching by color
Duplicate		None	T39535 Wikimedia Commons should support filtering by color
Resolved		None	T19503 Provide metadata support on Wikimedia Commons
Open		None	T122038 Moving/Deleting a video file does not move/delete subtitles files, nor does it inform the file mover of their existence
Open		None	T135221 Make TimedText content an integral part of the File page
Open	Feature	None	T2167 Use a dedicated interface for adding meta-data like interwiki links, rather than wikitext
Open		None	T132072 Integrate page meta-data as a new content model revision slot for consistency and atomicity
Resolved		None	T51662 VisualEditor: Use Multimedia/Wikidata's proposed rich structured meta-data in the image insertion dialog
Resolved		None	T68108 [Epic] Store media information for files on Wikimedia Commons as structured data
Open	Feature	None	T14963 allow per-page exceptions to spam blacklist
Open		None	T203157 Make the spam whitelist its own slot
Resolved		Halfak	T252280 Improve Wikilabels UI
Open		None	T105518 Make Wiki Labels mobile compatible
Open		None	T104072 Implement single column diff option (from mobile app)
Open	Feature	None	T56140 Move TemplateData to its own JSON-content namespace and associate with Template-namespace, or to its own TemplateData content model and revision slot
Stalled		None	T174043 Deploy Multi-Content Revisions
Open		None	T174022 Implement multi-content revisions
Open		None	T189220 Ensure that relevant extensions are MCR-aware
Open		None	T202763 Update extensions which customize content diff rendering
Open		None	T94370 Implement a mechanism that recognizes syntax errors of wikicode as a Huggle extension
Resolved		Petrb	T57793 Scoring should perhaps take into account added text rather than all text
Open		None	T100082 Provide useful diffs to high-volume consumers of recent changes
Open		None	T56328 Provide intraline diff format in API action=compare
Declined		None	T162210 [EPIC] Upstream MobileFrontend components to core and other extensions (tracking)
Open	BUG REPORT	None	T238507 MobileFrontend sometimes goes to diff page instead of pending changes review page
Open		None	T117279 [EPIC] Core should provide inline diffs as well as side by side (Move InlineDifferenceEngine into core / remove MobileDiff)
Resolved		ovasileva	T101796 MobileDiff appears strangely empty if previous revision is hidden
Stalled		None	T222562 Special:MobileDiff doesn't correctly handle diff=0 if the diff would cover multiple revisions
Resolved		Ammarpad	T224430 Improve appearance of Special:MobileDiff when looking for invalid revision (Maybe because it's deleted)
Open		None	T194830 Refactor DifferenceEngine
Stalled		None	T238331 Option for hiding changes should be added to AMC diff display
Open		None	T240608 Standardise a control for switching diff types from side by side to inline/visual
Resolved		phuedx	T240622 [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend
Open		None	T240624 Style desktop Minerva diff page to look like Special:MobileDiff
Resolved		ovasileva	T242310 Regression: issues with MobileDiff
Resolved		• marcella	T242351 HTML for VisualDiff mode button appears in mobile diff pages (disabled by hack)
Resolved		matmarex	T244673 VisualDiff feature on mobile has an inconsistent style/layout
Resolved	BUG REPORT	Esanders	T245172 VisualDiff toggle buttons appear in mobile when the relevant page doesn't have wikitext content model
Resolved		ovasileva	T243783 MobileDiff drops whitespaces from edits
Resolved		ovasileva	T243235 Regression: Desktop diff styles for moved paragraphs load alongside mobile
Resolved		Jdlrobson	T171726 MobileDiff with inconsistent linebreaks within words
Open		None	T199307 Determine treatment for empty lines in diffs
Resolved		• jkroll	T197729 wikidiff2 creating ins and del elements with single empty character element
Stalled	Feature	None	T298174 Mobile web diffs should show change tags
Open		None	T218428 Mobile diff is not clear about move direction
Stalled		None	T191706 It's not possible to undo/rollback edits from diff on Mobile

Event Timeline

There are a very large number of changes, so older changes are hidden. Show Older Changes

Masumrezarock100 mentioned this in T238331: Option for hiding changes should be added to AMC diff display.Nov 14 2019, 3:10 PM

Jdlrobson added a parent task: T238507: MobileFrontend sometimes goes to diff page instead of pending changes review page.Nov 17 2019, 11:55 PM

Jdlrobson mentioned this in T238507: MobileFrontend sometimes goes to diff page instead of pending changes review page.Nov 20 2019, 7:58 PM

ovasileva added a subtask: T238331: Option for hiding changes should be added to AMC diff display.Nov 26 2019, 11:27 AM

There's a -1 from @daniel and a +1 from @tstarling on https://gerrit.wikimedia.org/r/#/c/547057/ and I'm not quite sure what to do here.

@daniel writes:

This is a breaking change that violates the documented contract of this method. It's no better than just removing the method. Do we know that it does not break any subclass of ContentHandler?

Note that, since ContentHandler is designed to be subclassed by extensions, any protected methods are part of the stable public interface.

You can just do:
return $this->getSlotDiffRendererWithOptions( $context, [] );

I am on vacation till the 9th but will check in then... and write some unit tests.

Masumrezarock100 mentioned this in T224430: Improve appearance of Special:MobileDiff when looking for invalid revision (Maybe because it's deleted).Dec 1 2019, 10:38 AM

Change 547057 merged by jenkins-bot:
[mediawiki/core@master] Inline diffs upstreamed from MobileFrontend to core.

https://gerrit.wikimedia.org/r/547057

ReleaseTaggerBot edited projects, added MW-1.35-notes (1.35.0-wmf.10; 2019-12-10); removed MW-1.35-notes (1.35.0-wmf.5; 2019-11-05).Dec 8 2019, 10:00 AM

Announcing it in the next Tech news might be a good idea since you are removing MobileDiff and all.

Nothing is being removed yet. This is one change in a long line of changes so advertising this would be very confusing right now.
I can confirm the diff is available (example) but right now there is no UI to access it.

Next up:

Making it possible to switch to inline diff on desktop e.g. Vector:

https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/548936/5

Styling diff pages for Minerva to look like Special:MobileDiff

https://gerrit.wikimedia.org/r/547766

Removing MobileFrontend code in favor of upstreamed code

Later:

Removing Special:MobileDiff

I will be working on this during the course of the coming week :-)

This uses diff-type as URL parameter, while VisualDiff uses diffmode. I think it makes sense to decide on one common interface for different diffs -- both for URL parameters and for UI to switch between different diff styles -- before graduating any of them out of beta.

ovasileva closed subtask T224430: Improve appearance of Special:MobileDiff when looking for invalid revision (Maybe because it's deleted) as Resolved.Dec 9 2019, 6:43 PM

Just to clarify, what I could imagine as UI for diff switching, that would probably work well with VisualDiffs, is this:

In core, on server side: Add a button group (like the current one in VisualDiff) for switching, that simply links the different diff modes.

In core, on client side: Enhance that button group via JS to load the diffs via AJAX and show them without reloading the page.

For VisualDiff, on client side: Add a third button to the button group that will show the VisualDiff.

This would also solve T171437.

@Schnark yep that makes sense. We'll also want to standardise the control for switching in core so the VisualDiff extension can hook into adding the view.Would you be the person to collaborate with on VisualEditor-VisualDiffs or is there someone else I should speak to?

My only involvement with VisualDiffs is my user script https://de.wikipedia.org/wiki/Benutzer:Schnark/js/diff which hooks into the UI of VisualDiffs. I don't know who in the VE team currently feels responsible for the diffs, if there is anyone at all.

Jdlrobson removed a project: Patch-For-Review.Dec 12 2019, 8:26 PM

Jdlrobson updated the task description. (Show Details)

Jdlrobson updated the task description. (Show Details)Dec 12 2019, 9:15 PM

Jdlrobson moved this task from Doing to Next up on the User-Jdlrobson board.

Masumrezarock100 updated the task description. (Show Details)Dec 12 2019, 9:52 PM

Masumrezarock100 updated the task description. (Show Details)Dec 12 2019, 9:55 PM

Change 547594 abandoned by Jdlrobson:
Separate header generation from diff generation

Reason:
not working on this for now.

https://gerrit.wikimedia.org/r/547594

Jdlrobson changed the status of subtask T240622: [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend from Open to Stalled.Dec 20 2019, 3:53 PM

Does this still need code review from Platform Engineering?

In T117279#5777854, @daniel wrote:

Does this still need code review from Platform Engineering?

Not right now but input (guidance) is welcomed from TechCom (and core platform) on T240608

DanielFriesen removed a subscriber: DanielFriesen.Jan 6 2020, 9:05 PM

Jdlrobson changed the status of subtask T240622: [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend from Stalled to Open.Jan 7 2020, 5:30 PM

Masumrezarock100 mentioned this in T242310: Regression: issues with MobileDiff.Jan 9 2020, 3:26 AM

I am seeing some regressions in this change. I have created a subtask.

• Moushira removed a subscriber: • Moushira.Jan 9 2020, 11:35 AM

Another regression:

Structured data edit diffs are still being served side by side rather than inline if diff-type=inline is set

Steps to reproduce

View https://commons.wikimedia.org/w/index.php?title=File:%D0%A4%D0%BE%D1%82%D0%BE_%D0%90%D0%BB%D0%B8%D1%88%D0%B5%D1%80_%D0%A2%D0%B0%D1%88%D0%BC%D0%B0%D1%82%D0%BE%D0%B2_%D0%91%D0%BE%D0%B3%D0%B0%D1%80%D0%B4%D0%B8%D0%B5%D0%B2%D0%B8%D1%87.jpg&diff=388741403&diff-type=inline or any structured data diff

Actual results

Structured data edit diffs are still being served side by side even if diff-type=inline is set.

Expected results

We see a unified diff.

Masumrezarock100 added a project: Structured-Data-Backlog.Jan 20 2020, 6:19 PM

View https://commons.wikimedia.org

Note we don't support the new diff type officially on desktop. That's blocked on T240608.

I think this is an issue with mobile however?
https://commons.m.wikimedia.org/wiki/Special:MobileDiff/388741403

Thanks for the bug report I've opened T243235 to explore.

As I explained in,
T117279#5817692, I am seeing something like this on desktop mode. The diff is not shown unified even if I set diff-type=inline in the URL. The below screenshot is of https://commons.wikimedia.beta.wmflabs.org/w/index.php?title=File:Photo_on_14-01-2020_at_11.33.jpg&diff=216482&diff-type=inline&diffmode=source.

Screenshot_20200121-090348.png (480×960 px, 97 KB)

Similar problem on mobile. On mobile a structured data diff should be unified to be consistent with the normal wikitext diff. But I see side by side diffs. The below screenshot is of https://commons.m.wikimedia.beta.wmflabs.org/wiki/Special:MobileDiff/216482.

Screenshot_20200121-090309.png (480×960 px, 45 KB)

• Demian awarded a token.Jan 21 2020, 6:01 AM

Jdlrobson mentioned this in T243235: Regression: Desktop diff styles for moved paragraphs load alongside mobile.Jan 27 2020, 9:29 AM

ovasileva closed subtask T242310: Regression: issues with MobileDiff as Resolved.Feb 4 2020, 2:20 PM

ovasileva closed subtask T243235: Regression: Desktop diff styles for moved paragraphs load alongside mobile as Resolved.Feb 13 2020, 11:16 AM

Jdlrobson added a subtask: T245172: VisualDiff toggle buttons appear in mobile when the relevant page doesn't have wikitext content model.Feb 15 2020, 12:28 AM

Jdlrobson changed the status of subtask T240622: [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend from Open to Stalled.Jun 25 2020, 9:22 PM

Jdlrobson changed the status of subtask T240622: [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend from Stalled to Open.Jul 14 2020, 7:56 PM

Jdlrobson changed the status of subtask T238331: Option for hiding changes should be added to AMC diff display from Open to Stalled.Jul 27 2020, 10:35 PM

Jdlrobson changed the status of subtask T222562: Special:MobileDiff doesn't correctly handle diff=0 if the diff would cover multiple revisions from Open to Stalled.Jul 27 2020, 10:39 PM

Jdlrobson mentioned this in T222562: Special:MobileDiff doesn't correctly handle diff=0 if the diff would cover multiple revisions.

phuedx closed subtask T240622: [Technical debt payoff] Remove InlineDiffFormatter and InlineDifferenceEngine from MobileFrontend as Resolved.Sep 7 2020, 10:20 AM

matmarex closed subtask T245172: VisualDiff toggle buttons appear in mobile when the relevant page doesn't have wikitext content model as Resolved.Sep 17 2020, 6:18 PM

Change 547766 abandoned by Jdlrobson:
[mediawiki/skins/MinervaNeue@master] Style the desktop diff page of Minerva to look like Special:MobileDiff

Reason:
Not much bandwidth for this right now, but happy to provide code review for efforts pushing us in that direction.

https://gerrit.wikimedia.org/r/547766

Milimetric removed a subscriber: Milimetric.Jan 12 2021, 7:05 PM

Jdlrobson moved this task from Incoming to Nice to Have on the Desktop Improvements (Vector 2022) board.Mar 17 2021, 9:28 PM

Sorry moved this on accident, please disregard.

Jdlrobson added a subtask: T171726: MobileDiff with inconsistent linebreaks within words.Jun 22 2021, 8:16 PM

Jdlrobson added a subtask: T199307: Determine treatment for empty lines in diffs.Jun 22 2021, 8:20 PM

Jdlrobson moved this task from Next up to OKR Backlog on the User-Jdlrobson board.Jul 16 2021, 8:45 PM

Jdlrobson edited projects, added Readers-Web-Backlog (Needs Prioritization (Tech)); removed Desktop Improvements (Vector 2022), Readers-Web-Backlog (Tracking).Aug 31 2021, 10:07 PM

Jdlrobson moved this task from Backlog to Simplify MobileFrontend on the Readers-Web-Backlog (Needs Prioritization (Tech)) board.Aug 31 2021, 10:09 PM

Jdlrobson mentioned this in T290440: imported> on diff page should not link to contributions on Mobile view.Sep 7 2021, 3:53 PM

RhinosF1 added a subscriber: RhinosF1.Sep 7 2021, 4:21 PM

Jdlrobson updated the task description. (Show Details)Oct 14 2021, 5:28 PM

Jdlrobson moved this task from Simplify MobileFrontend to Page previews maintenance on the Readers-Web-Backlog (Needs Prioritization (Tech)) board.Dec 9 2021, 5:43 PM

Jdlrobson moved this task from Page previews maintenance to Future Unplanned on the Readers-Web-Backlog (Needs Prioritization (Tech)) board.

Jdlrobson moved this task from Future Unplanned to Remove History, Watchlist mobile special pages on the Readers-Web-Backlog (Needs Prioritization (Tech)) board.Dec 9 2021, 5:56 PM

ovasileva closed subtask T171726: MobileDiff with inconsistent linebreaks within words as Resolved.Dec 20 2021, 2:52 PM

MaxSem removed a subscriber: MaxSem.Dec 25 2021, 9:37 AM

TheDJ reopened subtask T171726: MobileDiff with inconsistent linebreaks within words as Open.Jan 12 2022, 9:55 PM

Jdlrobson mentioned this in T298645: On contributions page add hidden "No edit summary" element when an edit had no edit summary.Jan 18 2022, 5:42 PM

Jdlrobson closed subtask T171726: MobileDiff with inconsistent linebreaks within words as Resolved.Feb 8 2022, 6:05 PM

Jdlrobson added a subtask: T298174: Mobile web diffs should show change tags.Feb 16 2022, 4:43 PM

Jdlrobson changed the status of subtask T298174: Mobile web diffs should show change tags from Open to Stalled.

Jdlrobson mentioned this in T298174: Mobile web diffs should show change tags.

Jdlrobson added a subtask: T218428: Mobile diff is not clear about move direction.

Jdlrobson added a subtask: T191706: It's not possible to undo/rollback edits from diff on Mobile.Feb 16 2022, 4:45 PM

Jdlrobson changed the status of subtask T191706: It's not possible to undo/rollback edits from diff on Mobile from Open to Stalled.

LordProfo added a subscriber: LordProfo.Feb 17 2022, 12:51 AM

Samwalton9 updated the task description. (Show Details)Mar 21 2022, 2:16 PM

Jdlrobson mentioned this in T210168: [EPIC] Get rid of MobileFrontend's special pages for changes list where equivalents exist in core.Mar 30 2022, 10:36 PM

Samwalton9 added a project: Moderator-Tools-Team.May 11 2022, 12:53 PM

Samwalton9 moved this task from Backlog to Diff/Undo on the Moderator-Tools-Team board.

Samwalton9 updated the task description. (Show Details)May 11 2022, 1:17 PM

Jdlrobson updated the task description. (Show Details)May 25 2022, 5:52 PM

Jdlrobson moved this task from Remove History, Watchlist mobile special pages to Remove mobile diff page on the Readers-Web-Backlog (Needs Prioritization (Tech)) board.Jun 22 2022, 8:39 PM

Jdlrobson mentioned this in T327566: Mobile Page history and User contributions lists differ, making scripting hard.Jan 23 2023, 7:12 PM

Nardog added a subscriber: Nardog.Jan 23 2023, 7:43 PM

jsn.sherman mentioned this in T328035: [SPIKE] - Investigate technical approaches for improving mobile diffs [32hrs].Jan 26 2023, 7:11 PM

	F31518826: Screenshot_20200121-090309.png
	Jan 21 2020, 3:43 AM

	F31518822: Screenshot_20200121-090348.png
	Jan 21 2020, 3:43 AM

	F29716062: image.png
	Jul 9 2019, 12:03 AM

[EPIC] Core should provide inline diffs as well as side by side (Move InlineDifferenceEngine into core / remove MobileDiff)Open, MediumPublicActions