I have a shiny app with a number of tabPanels.
In one of these panels I want to write a time signal generated in seewave and tuneR to a www subdirectory.
If I run the commands on the R-promt, everything works, but I can't get it running in my server.R.
I tried observe, but then the input$ variables are not updated:
observeEvent(input$button,{
cat("Writing wav file")
})
eventReactive(input$button,{
"Inbutton"
pi<-4*atan(1)
s5<-synth(44100,5,input$freq1,input$amp1*2000,"sine",shape=NULL,p=0,
am=c(0,0,0),fm=c(0,0,0),harmonics=1,plot=FALSE,output="Wave")
s6<-synth(44100,5,input$freq2,input$amp2*2000,"sine",shape=NULL,
p=input$phase/180*pi,am=c(0,0,0),fm=c(0,0,0),
harmonics=1,plot=FALSE,output="Wave")
s7<-s5+s6
str(s7)
Wobj<-s7
wav_dir<-"./www"
wav_file<-file.path(wav_dir,"howling2.wav")
writeWave(Wobj,filename=wav_file)
play(s7)
})
I've managed somehow to save the file. I defined function that generates the sound and load it beforehand. Then in server function I call it like that:
server <- function(input, output){
observeEvent(input$button, {
sound <- sonify(input$name) # this is already a Wave object
wvname <- paste0("sound", input$button,".wav")
writeWave(sound, paste0("www/", wvname))
})
}
Then to implement it in UI follow this and this
Related
I'm trying to write tests in order to check if a shiny function fileInput() is reading files correctly.
My problem is that I don't know what to write in session$setInputs() in order to grab the file from my system.
Here is an example app:
library(shiny)
ui <- fluidPage(
tagList(
fileInput("file", "Please upload a file"),
tableOutput("text")
)
)
server <- function(input, output, session){
file <- reactive({input$file})
output$text <- renderTable({
req(file())
read.csv(file()$datapath)
})
}
shinyApp(ui, server)
Now, I want to be able to use testServer() in order to set a file address and see if my app loads it correctly, but I can't figure out how to do it:
address <- "path/to/text.csv"
testServer(server, {
session$setInputs(file = address)
print(file())
})
I think it has to do with the fact that fileInput() uploads the file to a temp folder and returns to shiny a dataframe where you can get the datapath, but I'm unable to simulate this pass in order to make the test work
I have the same question as you do, I did some investigating and could not find any way of testing fileInput with testServer or testthat. The best solution that I found was testing fileInput by taking a snapshot when recording a test with recordTest() of the shinytest package.
Sorry for answering this late.
I asked the same question at rstudio's forums and got an answer here
The basics of it are setting the file's datapath as a list:
address <- "path/to/text.csv"
testServer(server, { session$setInputs(file= list(datapath = address)) })
I am new to R and certainly very new to RShiny.
I wrote a packages which logs events into a log file. Rstudio is capable of viewing live logging unitl the file is 5MB. So now i am thinking about writing a Rshiny app that views the logs as they are being written to the file.
Which functions would help me to update the viewer?
Thanks!
You can call invalidateLater inside a reactive when you import the data. Data will be refreshed every time invalidateLater will fire (in my case every second).
Here a really silly example (my .csv doesn't update, it just prints that data is being refreshed to console):
library(shiny)
ui <- fluidPage(
tableOutput("data")
)
server <- function(input, output, session) {
# mtcars.csv will be read every second
mtcars_df <- reactive({
invalidateLater(1000, session)
read.csv("mtcars.csv")
})
# mtcars_df is a reactive, hence will force the table to re-render
output$data <- renderTable({
print(paste("Table refreshed at", Sys.time(), collapse = " "))
mtcars_df()
})
}
shinyApp(ui, server)
I have a shiny page looking like that:
library(all my required packages)
source("that file that contains a function to grab my data")
data <- function_from_sourced_file()
server <- function(input, output)
ui <- shinyUI()
shinyApp(ui = ui, server = server)
Now this works fine but I need the shiny app to reflect the changes on said data and to do so I have to either rerun the runApp() function or :w the app.R file in vim. Is it possible to ask the shiny server to rerun the entire file each it is accessed?
thanks
One of the quick ways to do so is using reactivePoll.
reactivePoll
Value
A reactive expression that returns the result of valueFunc, and invalidates when checkFunc changes.
Description
Used to create a reactive data source, which works by periodically polling a non-reactive data source.
Example
reactivePoll and reactiveFileReader
I developed a shiny app which displays some dynamic charts. These charts are generated at execution time according to the value of some buttons. This shiny app gets the data from a raw csv which is previously treated and transformed. I got a Rscript apart from the shiny app to do all those "transformations" of the raw data. What I would like to do is to call this Rscript from the shiny app in order to be executed when the shiny app is launched.
I have already checked these links but it didn't help at all: How can I connect R Script with Shiny app in R? and this one using Source() in Shiny. I checked the Rstudio documentation too: http://shiny.rstudio.com/tutorial/lesson5/.
I think it should be something like this, being procesadoDatos.R the RScript. i just want the source command to be executed at the beginning in order to load the data as the shiny app is starting:
source("procesadoDatos.R",local = TRUE)
shinyServer(function(input, output,session) {
(renderplots, reactives elements and so on)}
The Rscript is the shiny project path as the server.R and UI.R files. I also tried including the path but it didn't work either.
Another thing I tried was to create a function which makes all the transformations and then call it from server.R file after sourcing it:
source("procesadoDatos.R",local = TRUE)
generate_data(ticketsByService_report10.csv)
Being generate_data this function defined in the RScript:
generate_data <- function(csv_file) {
(all those transformation, data frame an so on)}
In all cases I got the same error saying that the data frames which are generated in the RScript aren't found.
Does anyone know what is wrong? Thanks in adavance
Scoping in Shiny
All this largely depends on where exactly you call source(). If you need the data to be found from within both the UI and the server function, you put source() outside the app.
If you place source() inside the server function, the UI won't be able to find any object created by the script. If you put this inside a render function, the objects are only visible inside that render function. See also Scoping rules for Shiny
Note that if you have separate server.R and ui.R files and you want the UI to find the objects created by the script, you should add a global.R file to your app directory. The source() command then goes in the global.R file.
A small example:
source('testScript.R')
shinyApp(
fluidPage(
selectInput("cols", "pick columns",
choices = names(x)),
dataTableOutput("what")),
function(input, output, session){
output$what <- renderDataTable(x)
}
)
and testScript.R contains one line:
x <- iris
The key here is:
the script actually has to create these objects
the script should be sourced in the correct spot.
So if you can do the following:
shinyApp(
fluidPage(
selectInput("cols", "pick columns",
choices = names(x)),
dataTableOutput("what")),
function(input, output, session){
source('testScript.R', local = TRUE)
output$what <- renderDataTable(x)
}
)
you get an error about not being able to find x. That's normal, because x is now only defined inside the environment of the server function.
You still can do this though:
shinyApp(
fluidPage(
dataTableOutput("what")),
function(input, output, session){
source('R/testScript.R', local = TRUE)
output$what <- renderDataTable(x)
}
)
Note how x is only needed inside the server function, not inside the UI.
Using functions
For functions, the same thing applies. You put the function definition in a script and source it like before. A function is nothing else but an object, so the script essentially creates a function object that then can be found using the exact same scoping rules.
Keep in mind though that this function should return something if you want to use the result of the function. So put this trivial example in testScript.R:
myfun <- function(x){
tmp <- iris[x]
return(tmp)
}
And now you can do the following:
source('testScript.R', local = TRUE)
shinyApp(
fluidPage(
selectInput("cols", "pick columns",
choices = names(myfun())),
dataTableOutput("what")),
function(input, output, session){
output$what <- renderDataTable(myfun(input$cols))
}
)
This doesn't work any longer if you put the source() inside the server function. The UI side won't be able to see myfun() any more.
rm(list = ls())
shinyApp(
fluidPage(
selectInput("cols", "pick columns",
choices = names(myfun())),
dataTableOutput("what")),
function(input, output, session){
source('R/testScript.R', local = TRUE)
output$what <- renderDataTable(myfun(input$cols))
}
)
# Error in myfun() : could not find function "myfun"
I'm trying to get a Shiny reactive UI running. It is getting quite complex (in terms of lines of code) so I thought refactoring was a good idea. To put it short, this is my server code:
require(ggplot2)
require(h2o)
shinyServer(function(input, output, session) {
#stop()
localH2o <<- h2o.init(nthreads = 3) #Global variable
source("BuilderServer.R", local = TRUE)[1]
source("ReviewerServer.R", local = TRUE)[1]
# CleanupFUnctions
session$onSessionEnded(function() {
rm(list=ls())
})
})
where I assumed source with local = TRUE was just like copy-paste the content of the R files. So they contain functions of the form output$functionName <- renderUI({code}). The ui code depends on these functions, most of them are reactive, the ui code looks like this:
shinyUI(navbarPage("Metamodel",
tabPanel("Build Custom Model",
fluidRow(
column(12,align="center",
uiOutput("BuilderUpTitle")
)
),
fluidRow(
column(3,
uiOutput("BuilderAxisSelector")
)
)
)
))
In this particular case, the "BuilderUpTitle" function looks like this:
output$BuilderUpTitle <- renderUI({
inFile <- input$BuilderInputFile
if(is.null(input$BuilderInputFile)){
fileInput("BuilderInputFile", "Upload a xlsx file")
} else {
#R Stuff done here with the file
textInput("text", label = h3("Model Title"), value = "Enter text...")
}
})
I wrote the code yesterday and it was working. Today I turned on the computer again, and when launching the app, not even the dependencies from the server.R appear to load (ggplot2 and h2o). The download button from the "BuilderUpTitle" function doesn't appear at all and shiny appears to only execute the ui.R code. I set the workspace to the folder of the sourcefiles and it doesn't help. Even if I uncomment the stop() function from the server, nothing seems to change. Setting breakpoints in RStudio doesn't stop the code inside the server, so that is why I think shiny is not calling the server function. However, the code was working before and I did not modify a single file. I even copied the content of the source files to the server.R code and still they do not load. Is there something obvious that I'm missing? Thank you in advance!
Ok, once again, I found myself what the problem is, and none of the things I said would've made anyone find what was wrong. Here is the tiniest possible code that reproduces the problem:
ui.R
shinyUI(fluidPage(
fluidRow(
uiOutput("itWillLock"),
uiOutput("itWillLock")
)
))
server.R
shinyServer(function(input, output) {
output$itWillLock <- renderUI({
sliderInput("slider","Slider",min=0,max=1,value=0)
})
})
I guess R gets stuck in an infinite loop and never reaches the server.R file. Is this a bug that I should report? Or just common sense will keep people out of this trouble. Thank you!