recode variable in reactive dataset

[Luigi Piccirilli]

hi everybody,

i wrote a little shiny code where some psychotherapists can do graphical diagnosis of questionaires.

i have different timestamps (messzeitpunkte), where these questionaires were completed. in dependence of these timestamps different datasets are build (f.e):

ui <- fluidPage(
  titlePanel(title = "Individualdiagnostik HSA"),
    sidebarLayout(
      sidebarPanel(
        fileInput(inputId = "datensatz", label = "1. Datensatz laden"),                     
          textInput(inputId = "pchiffre", label = "2. Patientenchiffre"),                     
            selectInput(inputId = "messzeitpunkt", label = "3.Messezeitpunkt auswählen",          ### Auswahl Dropdown Messzeitpunkt
              multiple = FALSE, selected = NULL,                                                   
                choices = c("Baseline" = "base",
                  "T0"       = "t0",
                  "T6"       = "t6",
                  "T12"      = "t12",
                  "T18"      = "t18",
                  "End"      = "end")),

server <- function(input, output) {
  datensatz_patient <- reactive({datensatz <- input$datensatz
    infile <- read.csv(datensatz$datapath, header = TRUE, ";", na = -77)
    patient <- input$pchiffre
    subset(infile, Chiffre == patient)})

messzeitpunkt <- reactive(input$messzeitpunkt)

CTQ_dat <- reactive(
  if (messzeitpunkt() == "base") 
    {subset(datensatz_patient(), select = c(Base_CTQ_v1:Base_CTQ_v28))} 
  else if (messzeitpunkt() == "end")
    {subset(datensatz_patient(), select = c(End_CTQ_v1:End_CTQ_v28))} else {})

Now i need to recode some variables in my CTQ_dat().

i tried:

CTQ_dat <- reactive(if (messzeitpunkt() == "base") {sub <- subset(datensatz_patient(), select = c(Base_CTQ_v1:Base_CTQ_v28)) }
  else if (messzeitpunkt() == "end")  {sub <- subset(datensatz_patient(), select = c(End_CTQ_v1:End_CTQ_v28)) } 
  else {}
recode(sub[5], "1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[7], "1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[10],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[13],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[16],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[19],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[22],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[26],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA")
recode(sub[28],"1=5; 2=4; 3=3; 4=2; 5=1; NA=NA"),
sub)

but it didnt work.

how can i recode some variables in a reactive dataset?
please give me a hint where my mistake is....

thank you very much