hidden inputs not working?

[Aaron Mackey]

Using an HTML UI, I've switched over a correctly-functioning Shiny webapp from a static multi-select box to a hidden input that gets populated via other JavaScript events.  Yet submitting the form now does not seem to trigger the reactive function that references those hidden inputs.  Pointers?

Thanks,

-Aaron

[Joe Cheng]

I think you may need to create and register an input binding. Please read this carefully:

http://rstudio.github.com/shiny/tutorial/#building-inputs

If that doesn't make sense to you, maybe you can provide some more details about how your app is constructed, and we'll see what we can do to help.

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[Aaron Mackey]

From your answer, can I assume then that while you automatically bind to select elements and other input elements, that you do not have an existing input binding to hidden input elements?

Thanks,

-Aaron

--
Aaron J. Mackey, PhD
Assistant Professor
Center for Public Health Genomics
University of Virginia
ama...@virginia.edu
http://www.cphg.virginia.edu/mackey

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[Joe Cheng]

That's correct. It would certainly be reasonable to have type="hidden" be automatically bound as well, except that there's no natural "value changed" event for them (that I know of).

You know, it might actually work to just have an input type="text" that happens to be hidden (e.g. style="display:none"). If a change event doesn't fire when you programmatically set the value, you can fire the event yourself using $(el).trigger('change'). Do this as soon as you set the value, there's no need to wait until submit is pressed.

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[Aaron Mackey]

In my case, I do want to have things wait until submit is pressed; but it seems that with a submit button on the page, that is what I get for free.  With the display:none textbox, I still need to trigger the change event regardless of the submit button, because otherwise Shiny doesn't think anything happened (and thus won't submit the form when I click the button).

Thanks!

-Aaron

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[Joe Cheng]

That's correct. You do need to manually trigger the change event on the hidden textbox, whether a submit button is around or not. But this is still easier than using <input type="hidden">, because for that you need to manually trigger the change event AND write an InputBinding for type="hidden" inputs. In the case of textboxes, the InputBinding already exists and is listening for change events and will do the right thing from there.

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[Indra Kshattry]

[Indra Kshattry]

Hello Joe,
I have the same problem, I want hidden but not trigger change. Is there any way that I can accomplish this task in R shiny web apps.

Thank you

Indra

On Wednesday, 9 January 2013 14:17:38 UTC-6, Joe Cheng [RStudio] wrote: