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[Feature Request] Inline clientside callbacks #956
Description
Right now our clientside callbacks need to reference a separate file - typically loaded in via assets - where the functions are defined in a special namespace:
window.dash_clientside = Object.assign({}, window.dash_clientside, {
large_params_function: function(largeValue1, largeValue2) {
return someTransform(largeValue1, largeValue2);
}
});Then in the app you reference these functions by namespace and name:
app.clientside_callback(
ClientsideFunction('clientside', 'large_params_function'),
Output('out-component', 'value'),
[Input('in-component1', 'value'), Input('in-component2', 'value')]
)From a user standpoint, at least for simple functions it would be convenient to be able to provide the function just as a string with the callback definition. We would then package these up with some automatic namespace and naming, either as a separate endpoint or just a special case of _dash-component-suites, and reference it in the generated index alongside all the other scripts.
app.clientside_callback(
"""
function(largeValue1, largeValue2) {
return someTransform(largeValue1, largeValue2);
}
""",
Output('out-component', 'value'),
[Input('in-component1', 'value'), Input('in-component2', 'value')]
)Reacted by Ryan Patrick Kyle, codeshokunin, Alex Batisse and Jan Beitner
Activity
jjaraalm commentedon Oct 11, 2019
Taking this one step further, it would be great if we could use a transpiler like Transcrypt to write the callback in python then convert it to js, Then the API for clientside callbacks and server callbacks could be integrated like
The simple and dumb way to do this would be to use
inspectto dump the source to a temporary file, transpile it, then load and deploy the js. We would probably want to do some preprocessing on the source to make sure the callback is "simple."The entire global context probably shouldn't be included in the transpiling, but we could allow users to pass in a context so that calls like
also work. In this case
iis always a fixed constant, but this would be helpful if/when programatically generating callbacks.Marc-Andre-Rivet commentedon Jan 14, 2020
@alexcjohnson Closing this as fixed. Let's open a new issue if there's a need for a follow up.