You might have already noticed that both the UI and server logic
functions in the source code of your SIA module have a special
imports
argument. While being set to NULL
by
default, once your module package is installed and the SIA app is run1, the
imports
argument is actually populated with a multitude of
objects that SIA app exports for your module. From the module’s
perspective, these form a list of imported objects, hence the name
“imports”. This vignette explains the nature of imports, how to use them
in your module, and how to communicate with the app to get the most out
of the module-app alliance that SIA modules offer.
Every single object defined in the SIA app that inherits from
reactive
, reactiveVal
or
reactivevalues
is relayed to the imports
list
available from within the module’s server function2.
reactive
s and reactiveVal
sTo use reactives and single reactive values, you have to “call” them.
There is no difference from usual shiny
conventions.
Refer to the source code of ShinyItemAnalysis app for the names of
the objects and server logic context, and/or possibly use
browser()
from within your module’s server function and
inspect imports
object by yourself3. It is also possible
to put cat(names(imports), sep = "\n")
in your module’s
function to get the object names listed in your console. However, we
recommend to stick with the former, as you can inspect the imports
interactively from R
console, save them, and then possibly
reuse in preview mode4, keeping the development cycle short.
input
s and reactiveValues
All SIA’s inputs are relayed to the same imports
object
described above. In your module, you’ll find them in
imports$input
.
For instance, to get the name of currently picked toy dataset in the
app, you would use imports$input$data_toydata
as your usual
input.
The idea is the same for reactivevalues
, as
input
in fact inherits from reactivevalues
. To
use reactive values, you simply use them by their name, as you would do
in ordinary shiny
code.
In case you want to update input values living outside your
module, it gets a bit trickier. You have to obtain the correct
session
object first, which is reliably done by subsetting
the parent session from your module’ current session. This code would
set the toy dataset to “CZmaturaS”:
parent_session <- .subset2(session, "parent")
updateSelectInput(
session = parent_session,
inputId = "data_toydata",
selected = "CZmaturaS_ShinyItemAnalysis"
)
/private/var/folders/b7/tz3d429j6q7cgl141c6kh96m0000gn/T/RtmpdauWKy/Rbuildd9905be6924/SIAtools/vignettes/imports.R
The chunk above would be placed in your regular
observer
, possibly bounded to some
actionButton
press or any other event with
bindEvent
. Note that if you use shiny modules inside a SIA
module, you have to get the correct session object for SIA, which could
possibly be “grandparent” or higher from your SIA module’s module
perspective.
Using ShinyItemAnalysis::run_app()
function.↩︎
Actually, UI function of a module possesses its
imports
as well, but the SIA app doesn’t provide any yet,
as we are currently unsure what to relay in an UI part.↩︎
Note again you have to build and install your module package first and run it within the SIA app to see the imports.↩︎
However, you have to shiny::isolate()
any
reactive expression first to store the actual object in a regular
non-reactive one. Then, you are expected to wrap the result in a simple
function that returns the object, so it plays nicely with the module’s
code that works with reactive expressions in imports.↩︎