When showing a ggplot in a shiny app, how do I capture the ggplot warning that appears in the console, and display in the app?

When you call ggplot it creates an object of type ggplot, as far as my understanding goes, internally, the messages aren't generated till you call print() on the object. There's an explanation on similar issue wrt messages so have a read Why does ggplot not allow suppressing of messages generated by its geoms?.

What we can do is explicitly print the ggplot and capture the messages

library(shiny)library(ggplot2)ui <- fluidPage(  titlePanel("This is now fixed :)"),  mainPanel(    plotOutput("my_plot_that_generates_warnings"),    tags$br(),    verbatimTextOutput(outputId='ggplot_warnings')  ))server <- function(input, output) {  data <- reactive({    ggplot(iris, aes(x=Sepal.Length, y=Sepal.Width)) +      geom_point() +      geom_smooth()  })  dataerrors <- reactive({    tryCatch({      print(data())    }, message = function(e) {      return(e$message)    }, warning = function(e) {      return(e$message)    }, error = function(e) {      return(e$message)    })  })  output$my_plot_that_generates_warnings <- renderPlot({    data()  })  output$ggplot_warnings <- renderPrint({    dataerrors()  })}shinyApp(ui = ui, server = server)