Implement ChatSteps and ChatStep to show/hide intermediate steps

[ahuang11]

Edit: see notebook for updated usage.

Closes #6598

The relationship:
ChatInterface > ChatFeed > Steps or Step
Steps > Step

Easily available to use by:
instance.step(**kwargs) -> instance.stream(ChatStep(**kwargs))
instance.steps(**kwargs) -> instance.stream(ChatSteps(**kwargs))
steps.step(**kwargs) -> steps.append(step)

ChatStep(s) methods mimic ChatFeed methods:
step.stream()
step.stream_title()

import time
import panel as pn

pn.extension()


def callback(contents: str, user: str, instance: pn.chat.ChatInterface):
    with instance.steps() as steps:
        for i in range(0, 4):
            with steps.step() as step:
                message = None
                for c in contents[i:]:
                    time.sleep(0.3)
                    message = step.stream(c, message=message)
                    step.title = f"Processing: {c}"

chat_interface = pn.chat.ChatInterface(callback=callback, callback_exception="verbose")
chat_interface.show()

These context managers are optional and the equivalent of:

import time
import panel as pn

pn.extension()


def callback(contents: str, user: str, instance: pn.chat.ChatInterface):
    steps = pn.chat.ChatSteps(title="Running...", status="running")
    instance.stream(steps)
    
    for i in range(0, 4):
        step = pn.chat.ChatStep(margin=0)
        step.title = "Running..."
        step.status = "running"
        steps.append(step)
        message = None
        for c in contents[i:]:
            time.sleep(0.3)
            message = step.stream(c, message=message)
            step.title = f"Processing: {c}"
        step.status = "completed"
    steps.title = step.objects[-1].object
    steps.status = "completed"

chat_interface = pn.chat.ChatInterface(callback=callback, callback_exception="verbose")
chat_interface.show()

Screen.Recording.2024-04-01.at.6.00.35.PM.mov

• docs
• tests
• serialize

[MarcSkovMadsen]

I'm overall very much for making progress reporting easy.

The first feedback I have is

• Is this functionality really chat specific. I believe many other processes/ flows would like to report back feedback like this. For example Streamlit made a status component. Not a chat_status component. The feature will be more valuable if its general.
• I like the context manager a lot. But if we introduce it here would it not be a good idea to analyze which components/ flows could benefit from a context manager approach and then make a general design specification?
• Rember to check look and feel with sizing_mode="stretch_width" and in a template (like FastListTemplate). I would also recommend finding some beautiful icons instead of colorful emojis that will not work great with specific accent colors and templates.

[ahuang11]

I like the idea of a Status component that inherits from Card.

I like the context manager a lot. But if we introduce it here would it not be a good idea to analyze which components/ flows could benefit from a context manager approach and then make a general design specification?

I'm not 100% sure that's neceessary since it's a matter of implementing __enter__ & __exit__ in the corresponding classes if needed--no special method names required.

[MarcSkovMadsen]

The reason i think its important with a strategy for Context managers is that its much easier to use a framework if it follows some general principløs. It's much harder if suddenly one component can be used as a Context manager and the rest of the components cannot.

[ahuang11]

Can you think of other components that context managers could be useful for?

I imagine indicators, boolean, Card/Accordion.

Also, maybe disabled/loading?

[ahuang11]

Cleaner layout:

Screen.Recording.2024-05-14.at.7.23.52.PM.mov

[codecov]

Codecov Report

Attention: Patch coverage is 97.61905% with 9 lines in your changes missing coverage. Please review.

Project coverage is 81.63%. Comparing base (97c2918) to head (be7d6c0).
Report is 12 commits behind head on main.

Files	Patch %	Lines
panel/chat/feed.py	85.00%	3 Missing ⚠️
panel/chat/step.py	96.70%	3 Missing ⚠️
panel/chat/__init__.py	50.00%	2 Missing ⚠️
panel/chat/utils.py	98.88%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6617      +/-   ##
==========================================
+ Coverage   81.52%   81.63%   +0.11%     
==========================================
  Files         318      324       +6     
  Lines       46776    47220     +444     
==========================================
+ Hits        38133    38547     +414     
- Misses       8643     8673      +30     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ahuang11]

Okay this is ready for review! See https://github.com/holoviz/panel/blob/1fbaac662d8e33887eebac7e215fa441e04c091b/examples/reference/chat/ChatStep.ipynb for usage.

I'm not sure if ChatSteps requires a separate gallery notebook?

[ahuang11]

Added some new methods while implementing holoviz/lumen#560. Need to change the docs, and also add tests, which I realized I didn't commit it and accidentally removed it locally :(

Screen.Recording.2024-05-22.at.11.01.27.PM.mov

[ahuang11]

ready for review now

Screen.Recording.2024-05-23.at.2.23.24.PM.mov

[philippjfr]

What happens right now if you .stream() when the last message contains ChatSteps could that not simply be used to attach a new step?

[philippjfr]

If this can't be removed I'd suggest renaming maybe, maybe add_step or stream_step?

[philippjfr]

append_step?

[ahuang11]

I decided against adding the functionality to stream since it can get quite complex due to the kwargs value accepting ChatMessage types and also message.

Instead, I compressed the two functions into append_step, where it accepts a steps kwarg which can be new, append, or a ChatSteps type.