By Steph
Following on from looking at the shiny modules design pattern of passing an input value to many modules, I’m now going to look at a more complex shiny module design pattern: passing an input from one module to another.
TL;DR
Return the input in a reactive expression from within the server call. Store the callModule() result in a variable. Pass the variable into arguments for other modules. Steal the code and, as always, if you can improve it do so!
Starting out
For the purposes of this post, I’ll be morphing the dummy application that Rstudio produces when you use New file > Shiny app. I’ve created a repository to store these design patterns in and the default shiny app that will be converted / mangled is the 01_original.R file.
The next step along was passing a top-level input to many modules. See file 02_singlegloballevelinput.R for the end to end solution.
Pass module input to other modules
Make a module that contains inputs
A module must have a server function and can optionally have UI and Input functions. We need a module that has an input function so our skeleton for our setup values is
setupInput Input parameters must be held in a tagList() so that the shiny UI knows to handle them like other directly mentioned inputs. The setupInput function can contain any number of inputs, including the bins input that used to be a global input.
setupInputOutput the input value
In the module with the input parameters, we may need to do stuff with the value and also make it available for other modules. To make the input parameter’s value available we need to put it within a …read more
Source:: r-bloggers.com