Let parent server of module know that something happened inside the module - shiny

Question

I am building an app that presents a data table and which allows you to add data. The adding of data is build by means of a form. This form is written by a module. What I want to happen is that one may fill out the form, press an 'add' button and that the data inside the table is updated.
As an example, could you help me figure out how to complete the following piece of code:
library(shiny)
library(shinydashboard)
moduleInput <- function(id){
ns <- NS(id)
sidebarPanel(
actionButton(ns("action1"), label = "click")
)
}
module <- function(input, output, session){
observeEvent(input$action1, {
# Do stuff here,
# -> let the parent module or server know that something has happened
})
}
ui <- fluidPage(
verbatimTextOutput("module.pressed"),
moduleInput("first")
)
server <- function(input, output, session){
# print the currently open tab
output$module.pressed <- renderPrint({
#-> Write that we have pressed the button of the module
})
callModule(module,"first")
}
shinyApp(ui = ui, server = server)
All I thus want to do is find an easy way to present TRUE in the output field module.pressed when something happend inside the module.
Thanks!

Answer 1

Modules can pass reactive expression(s) to calling apps/modules by returning them in their server function. The documentation provides a few examples on how to set up interactions between modules and calling apps - https://shiny.rstudio.com/articles/modules.html
If a module needs to use a reactive expression, take the reactive expression as a function parameter. If a module wants to return reactive expressions to the calling app, then return a list of reactive expressions from the function.
library(shiny)
moduleInput <- function(id){
ns <- NS(id)
sidebarPanel(
actionButton(ns("action1"), label = "click")
)
}
module <- function(input, output, session){
action1 <- reactive(input$action1)
return(reactive(input$action1))
}
ui <- fluidPage(
verbatimTextOutput("module.pressed"),
moduleInput("first")
)
server <- function(input, output, session){
action1 <- callModule(module,"first")
output$module.pressed <- renderPrint({
print(action1())
})
}
shinyApp(ui = ui, server = server)