Improve typing performance for large documents

[v-bharts]

Are you reporting a feature request or a bug?

BUG-There is a lag when typing characters Issue is major for korean and chinese language where some character goes missing whereas for english it renders after 2-3 seconds

Provide detailed reproduction steps (if any)

1. Paste some very large content in editor
2. Type some text

Expected result

The text should render without delay

Actual result

There is delay while typing characters

Other details

Similar issues on previous versions- https://dev.ckeditor.com/ticket/13924 https://dev.ckeditor.com/ticket/12062

• Browser: Edge, IE, Chrome
• OS: windows
• CKEditor version: 4.11.4
• Installed CKEditor plugins:

[jacekbogdanski]

I used ~500kB text on Chrome, but couldn't reproduce the issue. It works slower than the native contenteditable element obviously, but the typing experience is pretty well. I believe that on some low tech machines it may have a greater impact on performance, but it's not something easily fixable due to the complexity of the application. As for IE, the issue seems to be a browser upstream which has been explained in https://dev.ckeditor.com/ticket/13924 and https://dev.ckeditor.com/ticket/12062

Could you provide more information about the testing environment i.e.

• What plugins do you use?
• Can you reproduce the issue with the latest CKEditor 4.13.1?
• Do you have enabled any of the spellchecking features (see https://ckeditor.com/docs/ckeditor4/latest/features/spellcheck.html)?
• Do you use Undo feature?
• Do you see any performance improvements when disabling spellchecking / undo features (if enabled)?
• Could you provide minimal CKEditor4 demo with the issue using e.g. https://codepen.io and a text sample causing the issue?
• Could you give some small overview of the machine specs do you use (mostly ram and proc, eventually if it's low/high tech spec machine)?
• Could you provide screencast with the issue? Gif image would be very welcome.

[v-bharts]

1. Enabled plugins-"dialog,button,floatpanel,panel,panelbutton,justify,font,colorbutton,basicstyles,selectall,find,bidi,pastefromword,indentblock,colordialog,tabletools,contextmenu,"
2. I tried online playground which has 4.13.1 and the issue is not reproduced there.
3. Native browser spell check in enabled
4. No
5. I am able to repro it on playground where spell check is disabled
6. Pastebin for sample text- https://pastebin.com/jFE8bub1
7. i5 6500 3.2GHz, 32 GB
8. Type fast to see the lag

[jacekbogdanski]

Thanks for the sample. Indeed performance with the provided file is not perfect, also for the latest version of CKEditor4. However, I can see a significant performance drop even with native contenteditable, which means that overall Korean and Chinese languages have some impact on typing performance.

Nevertheless, it would be still nice to do research if we have some bottlenecks in the code which could improve typing performance. We also have reported https://github.com/ckeditor/ckeditor4/issues/3637 issue, but AFAIK it's more about just keeping pressed delete key than typing problem.

[JisungHan-MS]

Happy new year @jacekbogdanski Would you please give me a rough ETA of this fix? :)

[jacekbogdanski]

Happy New Year :smile: I'm sorry but I can't give any ETA for the improvement. This ticket will get an appropriate milestone once we start working on it.

[JisungHan-MS]

Hi @jacekbogdanski,

I hope you are doing good. If there is any update, please let me know. Thanks for your assistance.

[Mukeshdhakolia]

Hi @jacekbogdanski, I am from Infineon Technologies and our business users are significantly impacted by this issue so I would like to request you that please try and resolve the issue bit faster.

Please let us know your response.

[jacekbogdanski]

Please, if you are interested in this improvement, give the main ticket https://github.com/ckeditor/ckeditor4/issues/3750#issue-542552218 thumbs-up :+1: so it has better visibility for us when planning development iteration.

[sharangoudar]

Hello Jacekbogdanski

Currently, around 25 plus users affected with this issue in the production. Characters are missing when typing Korean language in the Edge browser and long delay in the Chrome browser.

Also noticed slowness for the English language as well while typing for email replies , specially when the email content is large .

Please help with fix. Will appreciated if we have any ETA for this fix.

Thanks & Regards SharanGouda

[MS-JisungHan]

Hello @jacekbogdanski

I would appreciate an update status of this fix. Do you have any progress or is there any plan to fix this issue?

I am looking forward to hearing from you. Thanks for your assistance in advance.

[jacekbogdanski]

@MS-JisungHan we are keeping an eye on the issue, but searching for bottlenecks is time-consuming and we cannot postpone current tasks over it. The issue is already on our planning milestone.

[MS-JisungHan]

@jacekbogdanski, @f1ames, I would appreciate an update progress of this issue. Thanks for your assistance in advance.

[MS-JisungHan]

Hi @jacekbogdanski, @f1ames, would you please let us know ETA of this fix? End-users report that the editor performance is not very good with long content especially for Email conversation area. Please prioritize this and help to enhance this.

[f1ames]

Hi @MS-JisungHan, unfortunatelly, we don't have any ETA for this issue due to other priorites.

As @jacekbogdanski mentioned in the comment above this is quite time consuming and results are hard to predict (and there might be some native/upstream issues which needs to be adressed by browser vendors too).

If you looking for a way to push this issue forward, you may contact our support team to see if there are any options to speed things up.

[MS-JisungHan]

Thanks @f1ames for your response. As suggested, I requested this to your support team and am waiting for resposne.

[MS-JisungHan]

Please kindly update progress of this ticket. Thanks for your assistance in advance.

[MS-JisungHan]

Dear Team,

I would appreciate an update status of this issue. I am looking forward to hearing from you.

[JisungHan-MS]

Dear Team,

Are there any update on this ticket?

Also regarding the severity of the issue its not only Korean or Chinese characters If the email is having large content while replying there is a lag for even English language emails.

Please advise

[lslowikowska]

Hey @JisungHan-MS this is Ludwika from the CKEditor team. I already sent the response to your inquiry via email twice (April & May) and it seems you haven't received it. I will send it once again in a while - would you please check your mailbox and confirm you've got it?

[MS-JisungHan]

Hi Ludwika,

I received your email. The purpose of the update request in the attached email is announcing the current status from CKEditor team to the MS VIP customers who are in the CC list. They pushes our MS support a lot and this can’t be manageable only from MS side since the product is CKEditor. Would you please do “Reply All” for the attached email and add your answer that you provided me last month? That would be very helpful to convince the VIP customer who pushes MS support and management team a lot.

Best regards, Jisung Han