Upgrade jQuery to 4.x, or consider removing it as dependency

[merijng]

jQuery 4 is available. Can you upgrade to it? It seems to provide a significant performance boost, at least according to the blog article.

If any libraries break the application, consider removing them—or even consider removing jQuery altogether (related: #17093).

[leonkosak]

Believe me, there is no plan to remove jQuery from MVC (Razor Pages) projects due to "deep usage" in all UI libraries that depend on jQuery.

[merijng]

@leonkosak I can imagine. In this case, upgrading to jQuery 4 should do the job, as described.

If you ask me, any UI library that does not support jQuery 4 can be considered inactive and should be replaced.

[leonkosak]

@merijng, I would also be very happy that MVC frontend of abp framerwork would not need jQuery as a dependency and use modern Javascript (also abandoning support for old browsers) and modernize package management (#24981 (comment)).
I do not think that MVC is outdated frontend technology. For some types of applications I think is better than using SPA frameworks.
Getting rid of jQuery in abp MVC would greately "modernize" MVC nowadays, although developers could include it later anyway based on their needs.

[merijng]

@leonkosak I fully agree! However, I’m not aware of the underlying dependencies, so I can imagine there being an intermediate step. I believe the choice is ultimately up to the ABP team (@maliming ?)

[leonkosak]

@merijng, the thing is that abp mvc frontend is using other libraries such as datatables2,... which also depend on jQuery.
This situation is basically that Volo should build all UI components for abp mvc from scratch using pure (moredn) Javascript.
This would be an ideal situation to modernize mvc, but belive me, most mvc developers do not care about this and would use jQuery.

Maybe AI can help now to modernize mvc javascript stack, but as I said - most mvc developers do not care about this so much.

[caobinqixu]

Issue:
When create new project with CLI and run, it report jquery error, the reason is jQuery 4.0.0 removed releated api,
e.g: jQuery.isFunction

Reference:
https://blog.jquery.com/2026/01/17/jquery-4-0-0/

[maliming]

See https://abp.io/support/questions/6468/Jquery-Datatablesnet#answer-3a0fff3c-dec5-9238-e0d3-ab77701e950f

[hikalkan]

@maliming consider to implement this please if possible and doesn't break anything.

[maliming]

ok, I'll investigate further.

[maliming]

We investigated this and here is the plan.

Step 1: jQuery 4 + jQuery Migrate (targeting 10.7)

• Upgrade @abp/jquery to jQuery 4.x and add jQuery Migrate 4.x to the default bundles (load order: jquery -> jquery-migrate -> abp.jquery.js and plugins).
• Fix the removed API usages in our own code, eg $.isFunction in abp.jquery.js and the $.proxy calls in the bundled daterangepicker source. Pro modules and LeptonX themes have a few similar usages, they will be handled together.
• Upgrade jquery-validation to 1.22.1, it already supports jQuery 4.
• jquery-validation-unobtrusive hasn't been updated since 2022 and still calls $.parseJSON / $.isFunction / $.proxy internally. Same for some other libraries we ship: bootstrap-datepicker, jstree, timeago, toastr, malihu-custom-scrollbar-plugin, jquery-form. These are unmaintained (some for 6-10 years), so official jQuery 4 support will never come from upstream.

That's why jQuery Migrate stays in the default bundle for now: it restores the removed APIs at runtime, so both these libraries and your existing application code keep working after the upgrade. If you want to clean up your own code, run the dev build of Migrate and follow the JQMIGRATE console warnings.

Step 2: replace the unmaintained libraries (gradually, after 10.7)

For example timeago -> timeago.js, toastr -> Bootstrap Toast, malihu-custom-scrollbar-plugin -> native CSS scrollbars, jquery-form -> fetch + FormData. Date pickers and jstree need more evaluation since they are used in many places. Once these are gone, jQuery Migrate can be dropped.

Step 3: removing jQuery completely

This is a much bigger topic. All MVC UI packages depend on jQuery (JQueryScriptContributor is the root of the script contributor chain), and existing applications rely on abp.jquery.js. So this is a separate track, related to #17093, not part of this upgrade.