Handle special arguments when extracting parameter names for view API page

[abidlabs]

Closes: #8399

Test with:

import gradio as gr
import time


def echo(message, request: gr.Request, num):
    return message

demo = gr.Interface(
    echo,
    ["textbox", "slider"],
    ["textbox"],
)

demo.launch()

For the case of gr.ChatInterface, we can't get the original parameter names because we construct a wrapper function over the user's defined function, so in such cases, the parameter names are generated automatically:

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Handle special arguments when extracting parameter names for view API page

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[freddyaboulton]

Can we use something like functools.wraps in the chat_interface case to preserve the original signature?

Also, I was wondering why we need to construct the special args within the chat_interface function. Shouldn't that be handled by the regular request life-cycle in Blocks.

[abidlabs]

Can we use something like functools.wraps in the chat_interface case to preserve the original signature?

I think so yes I'll take a look

Also, I was wondering why we need to construct the special args within the chat_interface function. Shouldn't that be handled by the regular request life-cycle in Blocks.

Sorry what are you referring to by this?

[freddyaboulton]

Sorry what are you referring to by this?

If we can use something like functools.wraps to preserve the original signature, then I don't think we need to call special_args within submit_fn because gr.Blocks will know to pass the request as an input if it sees the type hint.

[abidlabs]

Thanks @freddyaboulton for the suggestion. Refactored to use functools.wraps, so now we handle gr.ChatInterface with additional parameters correctly as well. For the example in the original issue, we now have:

[freddyaboulton]

Nice. The api fn implementation for chatinterface is a lot cleaner now.

[abidlabs]

Indeed. Thanks @freddyaboulton for the reviews and suggestions.