shiny web app tabs layout plots data and text in one tab but plots only data in the other tab

[jrhudy57]

Hello; I have a web app with two tabs. my app appropriately plots data and renders text in one tab, but when i try the other tab, it plots only the data and throws an error when i render the text. below is my first effort at a reprex. thanks!

...``` r

here are my practice data:

dat

p q r s t

1 AK 70.1 0.000 280.7 0.000

2 AL 98.3 0.082 437.9 0.082

3 AR 88.9 0.088 421.4 0.088

4 AZ 57.5 0.000 268.7 0.000

5 CA 69.3 0.008 284.6 0.008

6 CO 67.0 0.000 248.6 0.000

7 CT 52.6 0.040 285.9 0.040

8 DC 71.8 0.000 393.8 0.000

9 DE 77.7 0.170 324.0 0.170

10 FL 69.5 0.140 290.9 0.140

library(reprex)
dput(dat, "tempDat")
#> Error in dput(dat, "tempDat"): object 'dat' not found
datAgain<-dget("tempDat")
print(datAgain)
#> NULL

here is my code:

library(shiny); library(tidyverse)

ui <- fluidPage(

 titlePanel("Practice and Troubleshooting"),
 sidebarLayout(
      sidebarPanel(
           h3("Slope"),
           textOutput("slopeOut"),
           h3("Intercept"),
           textOutput("intOut")
      ),
      mainPanel(
           tabsetPanel(
                tabPanel("Tab1", plotOutput("plot1", brush=brushOpts(id="brushP"))),
                tabPanel("Tab2", plotOutput("plot2", brush=brushOpts(id="brushP")))
           )
      )))

server<-function(input,output){

 # Create a reactive expression for tab1 input
 model1 <- reactive({
      brushed_data1<-brushedPoints(dat, input$brushP, xvar="r", yvar="q")
      if(nrow(brushed_data1) < 2){
           return(NULL) 
      }
      lm(q~r, input$brushP, data = brushed_data1)
 })
 
 # Create a reactive expression for tab2 input
 model2 <- reactive({
      brushed_data2<-brushedPoints(dat, input$brushP, xvar="t", yvar="s")
      if(nrow(brushed_data2) < 2){
           return(NULL) 
      }
      lm(s~t, data = brushed_data2)
 })
 
 # render slope text for model1
 output$slopeOut <- renderText({
      if(is.null(model1())){
           "No Model Found"
      } else {
           model1()[[1]][2]
      }
 })
 
 # render intercept text for model 1
 output$intOut <- renderText({
      if(is.null(model1())){
           "No Model Found"
      } else {
           model1()[[1]][1]
      }
 })
 
 # render slope text for model 2
 output$slopeOut <- renderText({
      if(is.null(model2())){
           "No Model Found"
      } else {
           model2()[[1]][2]
      }
 })
 
 # render intercept text for model 2
 output$intOut <- renderText({
      if(is.null(model2())){
           "No Model Found"
      } else {
           model2()[[1]][1]
      }
 })
 
 # render tab1 plot
 output$plot1<-renderPlot({
      plot(dat$r, dat$q, xlab="xlab", ylab="ylab", main="Practice Plot 1", cex=1.5, pch=16, bty="n")
      if(!is.null(model1())){
           abline(model1(), col="blue", lwd=2)
      }
 })
 
 # render heart disease plot
 output$plot2<-renderPlot({
      plot(dat$t, dat$s, xlab="xlab", ylab="ylab", main="Practice Plot 2", cex=1.5, pch=16, bty="n")
      if(!is.null(model2())){
           abline(model2(), col="blue", lwd=2)
      }
 })

}

shinyApp(ui=ui,server=server)

<div style="width: 100% ; height: 400px ; text-align: center; box-sizing: border-box; -moz-box-sizing: border-box; -webkit-box-sizing: border-box;" class="muted well">Shiny applications not supported in static R Markdown documents</div>

<sup>Created on 2022-01-26 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)</sup>