I have a problem for design a nested input/output app. (I have also tried to post this question to shiny-discuss. However, it would be automatically deleted when I post. Why?)
My app can be simplified as the following steps:
Input dataset by textarea. i.e.: input$textarea.in
Load dataset and show the name list of the imported dataset. User could select data by selectInput. i.e: uiOutput("choosedata")
Compute the range of selected data and then display a sliderInput. i.e.: uiOutput("range")
Finally, compute the square of value selected by sliderInput. i.e.:verbatimTextOutput("range.out")
That is:
input => uiOutput => uiOutput => output
(work!) (work!) (error!)
The error will happen at step 4 after changing imported dataset. To be more specific, the initial input format is:
Data.A 1 2 3 4 5
Data.B 6 7 8 9 10 11
Another input format is:
Data.C 1 3 5 7
Data.D 2 4 6 8
Steps 2 and 3 would automatically change, but step 4 wont. How to fix it?
Best
Note that the online app and code are following:
http://glimmer.rstudio.com/tchsieh/myapp/
#=========================
#ui.R
#=========================
library(shiny)
shinyUI(pageWithSidebar(
headerPanel("Title"),
sidebarPanel(
p("Text Area:"),
tags$textarea(id="textarea.in", rows=3, "Data.A 1 2 3 4 5 \nData.B 6 7 8 9 10 11"),
uiOutput("choosedata"),
uiOutput("range")
),
mainPanel(
h2("Test"),
h3("Raw Data (step1: work!)"),
verbatimTextOutput("textarea.out"),
h3("Range of the selected data (step2: work!)"),
verbatimTextOutput("summary"),
h3("Squared of the selected value (step3:error when change Text area)"),
verbatimTextOutput("range.out")
)
))
#=========================
#server.R
#=========================
library(shiny)
shinyServer(function(input, output) {
loadPaste <- reactive({
text <- input$textarea.in
temp <- lapply(readLines(textConnection(text)), function(x) scan(text = x, what='char'))
out <- list()
out.name <- 0
for(i in seq_along(temp)){
out.name[i] <- temp[[i]][1]
out[[i]] <- as.numeric(temp[[i]][-1])
}
names(out) <- t(data.frame(out.name))
out
})
output$textarea.out <- renderPrint({
loadPaste()
})
output$choosedata <- renderUI({
dataname <- names(loadPaste())
dataList <- list()
for(i in seq_along(dataname)){
dataList[[i]] <- dataname[i]
}
selectInput("dataset", "Select dataset:", choices = dataList, selected = dataList[1])
})
output$summary <- renderPrint({
out <- loadPaste()
id <- which(names(out) == input$dataset)
mydata <- out[[id]]
range(mydata)
})
output$range <- renderUI({
out <- loadPaste()
id <- which(names(out) == input$dataset)
mydata <- out[[id]]
sliderInput("range.in", "Selecte a value in the range of data", min=min(mydata), value=mean(mydata), max=max(mydata), step=diff(range(mydata))/10)
})
output$range.out <- renderPrint({
(input$range.in)^2
})
})
