Bugfix: null dereference resizing empty textbox

[cobryan05]

Fixes "TypeError: Cannot read properties of null (reading 'trim')" when resizing an empty textbox. 'value' is an Optional parameter so must be null checked before empty checked.

This causes Sygil-Dev/sygil-webui#656 . It prevents the UI from appearing at all if the input prompt is defaulted to multiline. The fix is a simple null check.

Checklist:

• [x ] I have performed a self-review of my own code
• [ x] My code follows the style guidelines of this project
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• [x ] New and existing unit tests pass locally with my changes

[cobryan05]

bump I'm not sure if this is waiting for anything (like retriggering the build bot? I don't know how to do that)

[pngwn]

Is there a simple reproduction of this issue anywhere? The linked issue doesn't give me much to go by without digging into the source code of the stable-diffusion-webui.

[cobryan05]

Reproducing was even simpler than I thought 😆 .

import gradio as gr

with gr.Blocks() as demo:
    box = gr.Textbox(value=None)
demo.launch()

results in

Uncaught (in promise) TypeError: Cannot read properties of null (reading 'trim')
    at text_area_resize (index.843bae95.js:276:14)
    at Object.m (index.843bae95.js:51:78)
    at Object.m (index.843bae95.js:180:13)
    at mount_component (index.aa663a61.js:1039:26)
    at Object.m (index.843bae95.js:421:4)
    at Object.m (Block.25e59696.js:45:18)
    at Object.m (Block.25e59696.js:106:39)
    at mount_component (index.aa663a61.js:1039:26)
    at Object.m (index.843bae95.js:489:4)
    at mount_component (index.aa663a61.js:1039:26)

Not sure exactly how 'None' is getting there in webui, since it should be being set to '' ... but TextBox's value is marked as

value: Optional[str | Callable] = "",

so it shouldn't crash if 'None' is in there

[abidlabs]

We can always map null to "" in the backend for Textbox, but I think given that other components like Number and Image support being null, I think Textbox should as well @pngwn?

[abidlabs]

Thank you for the PR @cobryan05. We discussed this and figured it's better to fix this via the backend. We've merged in a fix here: #2264, so this should now work on main. We'll also release a version to pypi by the end of the week.