Operation Not Allowed Active Reactive Context - Subset in RShiny - r

Question

I want to create a subset dataframe in shiny to output various filtered options in my ploy. In the UI, my variable PLAN_DIM_CK are my different choices, and each PLAN_DIM_CK number is the what I want to subset by. When I run the code, I get the error "Operation not allowed without an active reactive context (You tried to do something that can only be done inside a reactive expression or observer.)
Can anyone help me with where this issue lies?
# Filter by plan in UI
selectInput(inputId = "PlanID",
label = "Select a Plan",
choices = unique(vbc2$PLAN_DIM_CK)
In the server
#within server
subsetTest <- reactive ({
subset(vbc2, PLAN_DIM_CK == input$planID)})
y <- subsetTest()$RISK_ADJUSTED_HBR
x <- subsetTest()$PANEL_SIZE
output$distPlot <- renderPlot({
ggplot(data = subsetTest(), aes(x=y,y=x))

Answer 1

My best guess would be that you need to use observe. The x and y variables should be inside observe, something similar to this:
observe({
y <- subsetTest()$RISK_ADJUSTED_HBR
x <- subsetTest()$PANEL_SIZE
})
Using global variables like this is not a good option. I would suggest you put this x and y variables inside your renderPlot or create reactive variables from it.
Putting it inside the renderPlot could be something like this:
output$distPlot <- renderPlot({
y <- subsetTest()$RISK_ADJUSTED_HBR
x <- subsetTest()$PANEL_SIZE
ggplot(data = subsetTest(), aes(x=y,y=x))
)}
Using reactive you could do something like this:
subsetTest <- reactive ({
subset(vbc2, PLAN_DIM_CK == input$planID)})
y <- reactive({subsetTest()$RISK_ADJUSTED_HBR})
x <- reactive({subsetTest()$PANEL_SIZE})
output$distPlot <- renderPlot({
ggplot(data = subsetTest(), aes(x=y(),y=x()))
Also, it would be better that you provide a minimal reproducible example from next time so that it would be easy to help you.