Reactive wrapper error

[k_Utkarsh]

Quite ironically, while preparing a reprex, I ran into following error, which I see no reason to occur, hence posting here. I've seen other similar errors, but not able to understand what is going wrong here. The error is:

Warning: Error in : Operation not allowed without an active reactive context. * You tried to do something that can only be done from inside a reactive consumer. 58: Error : Operation not allowed without an active reactive context. * You tried to do something that can only be done from inside a reactive consumer.

library(shiny)

ui <- fluidPage(
    sliderInput("x","X",min = 1,max = 100,value = 5),
    sliderInput("y","Y",min = 1,max = 100,value = 5),
    sliderInput("z","Z",min = 1,max = 100,value = 5),

    plotOutput("class_plot")
)


server <- function(input, output, session){

    
   observe(req(input$x),{
     x <- reactive(input$x)
     y <- reactive(input$y)
     z <- reactive(input$z)
     
     
     result <- reactive(eval(parse(text = "36+x()*6+y()*3+z()*2")))
     first <- reactiveVal(NULL)
     second <- reactiveVal(NULL)
     
     if(result()<= 100){first("red")}
     else if(result() >100 & result() <= 200){first("blue")}
     else if(result() >200 & result() <= 300){first("green")}
     else if(result() >300 & result() <= 400){first("yellow")}
     else if(result() >400 & result() <= 500){first("orange")}
     else {first("No_way")}
     
     if(result()<= 200){second("easy")}
     else if(result() > 200 & result() <= 400){second("medium")}
     else {second("Difficult")}
     
     output$class_plot <- renderPlot({
       NULL
     })
   })
}


shinyApp(ui, server)

Thanks in advance.

[nirgrahamuk]

@k_Utkarsh

observe(req(input$x),{

your wrote observe(
but you passed parameters as if you intended observeEvent(