[ZEPPELIN-6214] Fix new web app to handling carriage return

[shmruin]

What is this PR for?

Fix an issue where the new Angular UI (zeppelin-web-angular) does not correctly handle carriage return (\r) characters.
This causes outputs like progress bars(#) or status updates that use \r to overwrite lines to appear ugly and unnecessarily long.

This implementation is a direct port of the previous logic from the classic UI (zeppelin-web), specifically based on the original implementation in result.controller.js and result.js.

Additionally, this update changes the behavior of the carriage return (\r) character to better emulate standard terminal functionality.

Instead of clearing the entire line, the \r character now moves the cursor to the beginning of the line and overwrites the existing text. This "terminal-like" partial overwrite behavior is more accurate and what most interpreters expect.

This enhancement has been applied to both the classic and new UIs for consistent, standards-compliant output.

What type of PR is it?

Bug Fix

Todos

What is the Jira issue?

[ZEPPELIN-6214]

How should this be tested?

• Any zeppelin notebook paragraph that generating progress bar (#) is the easiest to test this change.
• Or you can reproduce the Jira Issue ticket's situation by running the code. Installing conda, set your own conda env, and set path in zeppelin is required.
• For testing terminal-like CR behavior - you can run the code like below in zeppelin notebook with shell interpreter.

printf 'Initializing system, please wait...\rLoading components...\n'
printf 'Progress: [25%%]\rProgress: [50%%]\rProgress: [100%%]\n'

Screenshots (if appropriate)

• Current Version

• Fixed Version (with supporting terminal-like carriage return)

Questions:

• Does the license files need to update? N
• Is there breaking changes for older versions? N
• Does this needs documentation? N

[Reamer]

LGTM, but I'm no frontend developer. More opinions are welcome.

[tbonelee]

Thanks for porting the carriage return handling form the classic UI!

Just a quick note. The current implementation replaces the whole line with only the last part after \r, so something like Hello World\rDone ends up as Done.
But in most REPLs or terminal-like environments, \r usually acts as a partial overwrite. So the expected output would be Doneo World, since only the beginning of the line gets overwritten and the rest stays as is.

Since interpreters are writing output with that behavior in mind, I think it might make sense to handle it that way in the new UI too. What do you think?

[shmruin]

Thanks for porting the carriage return handling form the classic UI!

Just a quick note. The current implementation replaces the whole line with only the last part after \r, so something like Hello World\rDone ends up as Done.

But in most REPLs or terminal-like environments, \r usually acts as a partial overwrite. So the expected output would be Doneo World, since only the beginning of the line gets overwritten and the rest stays as is.

Since interpreters are writing output with that behavior in mind, I think it might make sense to handle it that way in the new UI too. What do you think?

Thanks for your review. I agree with your suggestion and will test that feature. But doesn't the classic UI reflect this feature? Would it be better to fix both classic and new UI?

[tbonelee]

I also prefer fixing both the classic and new UI so they stay consistent.
Just wanted to check, @Reamer. I don't think this would break anything, but is there any chance someone might rely on the current behavior?

Probably not, but figured I'd ask just in case.
If it sounds good, maybe we could update both to match.

[Reamer]

I am not aware of anything like this. The new implementation is then simply not backported. This allows us to make breaking changes.

[shmruin]

@tbonelee I fix the code to support terminal-like carriage return. Now \r correctly move to the front, and overwrite the output. This feature is applied to both classic and new angular UI, as they are not so different.

I tested this in shell interpreter. (+ python interpreter, also)

%sh
printf 'Initializing system, please wait...\rLoading components...\n'
printf 'Progress: [25%%]\rProgress: [50%%]\rProgress: [100%%]\n'

[tbonelee]

LGTM. I'm just asking to be sure, but didn’t @Reamer’s comment suggest that it might be better not to backport this to the Classic UI?
If that's the case, then I guess there's no need to modify zeppelin-web, so I wanted to check.