R shiny Handsontable : use dataframe from handsontable - r

Question

In the below toy example I have a data set datapred. The data set are output to an interactive table using rhandsontable. Then I covert it in a new data.frame with hot_to_r. My issue is that when I wnat to use it in my function prediction(), it send me an error message and the application crash. I don't understand why.
I'm french so I converted in english the message :
Error in as.name: the 'pairlist' object can not be automatically converted to a 'symbol' type.
library(shiny)
library(frailtypack)
library(rhandsontable)
data("readmission", package = "frailtypack")
ui <- fluidPage(
titlePanel("prediction"),
mainPanel(
fluidRow(rHandsontableOutput("hot")),
br(),
plotOutput("pred")
)
)
server <- function(input, output) {
newdata <- subset(readmission,select = c("time","event","id","dukes"))
datapred <- newdata[1,]
data <- reactive({
DF = hot_to_r(input$hot)
DF
})
model <- frailtyPenal(Surv(time,event)~cluster(id)+dukes,n.knots=10,
kappa=10000,data=readmission)
predict <- reactive(
prediction(model, data(),t=200,window=seq(50,1900,50),
MC.sample=100))
output$hot <- renderRHandsontable({
rhandsontable(datapred)
})
data <- reactive({
DF = hot_to_r(input$hot)
DF
})
output$pred <- renderPlot({
plot(predict(),conf.bands=TRUE)
})
}
shinyApp(ui = ui, server = server)

Answer 1

You could simply evaluate the data() first, like this. I also added some checks so you don't get other errors during the initialization
library(shiny)
library(frailtypack)
library(rhandsontable)
data("readmission", package = "frailtypack")
ui <- fluidPage(
titlePanel("prediction"),
mainPanel(
fluidRow(rHandsontableOutput("hot")),
br(),
plotOutput("pred")
)
)
server <- function(input, output) {
newdata <- subset(readmission,select = c("time","event","id","dukes"))
datapred <- newdata[1,]
data <- reactive({
hot <- input$hot
if (!is.null(hot)) hot_to_r(hot)
})
model <- frailtyPenal(Surv(time,event)~cluster(id)+dukes,n.knots=10,
kappa=10000,data=readmission)
predict <- reactive({
dat <- data()
if (!is.null(dat)) {
prediction(model, dat,t=200,window=seq(50,1900,50),
MC.sample=100)
}
})
output$hot <- renderRHandsontable({
rhandsontable(datapred)
})
output$pred <- renderPlot({
pred <- predict()
if (!is.null(pred)) plot(pred, conf.bands = TRUE)
})
}
shinyApp(ui = ui, server = server)