CODEWITHSUNDEEP
javascriptrshiny
Holger Brandl
Holger Brandl

Reputation: 11192

How to redirect to a dynamic URL in shiny?

in a shinty application, I'd like to redirect the user to another URL when she is clicking on a point in a plot. The redirect itself is working based on the solution presented in https://stackoverflow.com/a/47158654/590437, however, it's unclear to me how to incorporate a dynamic property(which is calculated on the server-side) into the URL.

Example:

library(shiny)
library(ggplot2)

jscode <- "Shiny.addCustomMessageHandler('mymessage', function(message) {window.location = 'http://www.google.com';});"

ui <- fluidPage(
tags$head(tags$script(jscode)),
plotOutput("scatter", click = "plot_click")
)

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

    observeEvent(input$plot_click, {
        selectedTiles = nearPoints(iris, input$plot_click, threshold = 100, maxpoints = 1)

        if(nrow(selectedTiles)>0){
            # todo how to include the species in the redirect URL?
            # e.g. https://www.google.com/?q=versicolor
            session$sendCustomMessage("mymessage", "mymessage")
        }
    })

    output$scatter = renderPlot({
        ggplot(iris, aes(Sepal.Width, Petal.Width)) + geom_point()
    })
}

shinyApp(ui,server)

So when triggering the redirect with sendCustomMessage to run the java-script, how could I include a dynamic query parameter (in this example the selected species)?

Upvotes: 0

Views: 1408

Answers (1)

Pork Chop
Pork Chop

Reputation: 29387

You just pass the argument into the mymessage function, like so:

library(shiny)
library(ggplot2)

jscode <- "Shiny.addCustomMessageHandler('mymessage', function(message) { window.location = message;});"

ui <- fluidPage(
  tags$head(tags$script(jscode)),
  plotOutput("scatter", click = "plot_click")
)

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

  observeEvent(input$plot_click, {
    selectedTiles = nearPoints(iris, input$plot_click, threshold = 100, maxpoints = 1)

    if(nrow(selectedTiles)>0){
      # todo how to include the species in the redirect URL?
      url <- "https://stackoverflow.com/questions/57755830/how-to-redirect-to-a-dynamic-url-in-shiny/57756048#57756048"
      session$sendCustomMessage("mymessage", url)
    }
  })

  output$scatter = renderPlot({
    ggplot(iris, aes(Sepal.Width, Petal.Width)) + geom_point()
  })
}

shinyApp(ui,server)

Upvotes: 2

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