New to Gradio? Start here: Getting Started

To install Gradio from main, run the following command:

pip install https://gradio-builds.s3.amazonaws.com/63048975c6c055ac33360d21e760b9ce8f035ff5/gradio-4.37.2-py3-none-any.whl

*Note: Setting share=True in launch() will not work.

← make_waveform

set_static_paths →

on

gradio.on(···)

Description

Sets up an event listener that triggers a function when the specified event(s) occur. This is especially useful when the same function should be triggered by multiple events. Only a single API endpoint is generated for all events in the triggers list.

Example Usage

import gradio as gr

with gr.Blocks() as demo:
    with gr.Row():
        input = gr.Textbox()
        button = gr.Button("Submit")
    output = gr.Textbox()
    gr.on(
        triggers=[button.click, input.submit],
        fn=lambda x: x,
        inputs=[input],
        outputs=[output]
    )

demo.launch()

Initialization

Parameter	Description
`triggers` list[EventListenerCallable] \| EventListenerCallable \| None default: None	List of triggers to listen to, e.g. [btn.click, number.change]. If None, will listen to changes to any inputs.
`fn` Callable \| None \| Literal['decorator'] default: "decorator"	the function to call when this event is triggered. Often a machine learning model's prediction function. Each parameter of the function corresponds to one input component, and the function should return a single value or a tuple of values, with each element in the tuple corresponding to one output component.
`inputs` Component \| list[Component] \| set[Component] \| None default: None	List of gradio.components to use as inputs. If the function takes no inputs, this should be an empty list.
`outputs` Block \| list[Block] \| list[Component] \| None default: None	List of gradio.components to use as outputs. If the function returns no outputs, this should be an empty list.
`api_name` str \| None \| Literal[False] default: None	Defines how the endpoint appears in the API docs. Can be a string, None, or False. If False, the endpoint will not be exposed in the api docs. If set to None, the endpoint will be exposed in the api docs as an unnamed endpoint, although this behavior will be changed in Gradio 4.0. If set to a string, the endpoint will be exposed in the api docs with the given name.
`scroll_to_output` bool default: False	If True, will scroll to output component on completion
`show_progress` Literal[('full', 'minimal', 'hidden')] default: "full"	If True, will show progress animation while pending
`queue` bool default: True	If True, will place the request on the queue, if the queue has been enabled. If False, will not put this event on the queue, even if the queue has been enabled. If None, will use the queue setting of the gradio app.
`batch` bool default: False	If True, then the function should process a batch of inputs, meaning that it should accept a list of input values for each parameter. The lists should be of equal length (and be up to length `max_batch_size`). The function is then required to return a tuple of lists (even if there is only 1 output component), with each list in the tuple corresponding to one output component.
`max_batch_size` int default: 4	Maximum number of inputs to batch together if this is called from the queue (only relevant if batch=True)
`preprocess` bool default: True	If False, will not run preprocessing of component data before running 'fn' (e.g. leaving it as a base64 string if this method is called with the `Image` component).
`postprocess` bool default: True	If False, will not run postprocessing of component data before returning 'fn' output to the browser.
`cancels` dict[str, Any] \| list[dict[str, Any]] \| None default: None	A list of other events to cancel when this listener is triggered. For example, setting cancels=[click_event] will cancel the click_event, where click_event is the return value of another components .click method. Functions that have not yet run (or generators that are iterating) will be cancelled, but functions that are currently running will be allowed to finish.
`trigger_mode` Literal[('once', 'multiple', 'always_last')] \| None default: None	If "once" (default for all events except `.change()`) would not allow any submissions while an event is pending. If set to "multiple", unlimited submissions are allowed while pending, and "always_last" (default for `.change()` and `.key_up()` events) would allow a second submission after the pending event is complete.
`every` float \| None default: None	Will be deprecated in favor of gr.Timer. Run this event 'every' number of seconds while the client connection is open. Interpreted in seconds.
`js` str \| None default: None	Optional frontend js method to run before running 'fn'. Input arguments for js method are values of 'inputs', return should be a list of values for output components.
`concurrency_limit` int \| None \| Literal['default'] default: "default"	If set, this is the maximum number of this event that can be running simultaneously. Can be set to None to mean no concurrency_limit (any number of this event can be running simultaneously). Set to "default" to use the default concurrency limit (defined by the `default_concurrency_limit` parameter in `Blocks.queue()`, which itself is 1 by default).
`concurrency_id` str \| None default: None	If set, this is the id of the concurrency group. Events with the same concurrency_id will be limited by the lowest set concurrency_limit.
`show_api` bool default: True	whether to show this event in the "view API" page of the Gradio app, or in the ".view_api()" method of the Gradio clients. Unlike setting api_name to False, setting show_api to False will still allow downstream apps as well as the Clients to use this event. If fn is None, show_api will automatically be set to False.

← make_waveform

set_static_paths →