tooltip on shiny R?

Question

I want to have a tool-tip in my Shiny R application. Is there any easy way to achieve that? For now, I am creating a density map and I want a simple tool-tip showing "click here to slide through years" while hovering the mouse over slider YEAR.

User Interface:

library(shiny)
shinyUI(pageWithSidebar(
  headerPanel("Density Map"),
  sidebarPanel(
    sliderInput("slider_year", "YEAR:", 
                min = 2001, max = 2011, value = 2009, 
                format="####", locale="us"
    )
  )
 ),

  mainPanel(  
    plotOutput("event_heatmap_map", width = "100%", height = "100%")
  )
))

Server Code:

library(shiny)
library(ggmap)
library(ggplot2)
mydata <- read.csv("/var/shiny-server/www/dMetrics.csv")
shinyServer(function(input, output) {
    output$event_heatmap_map <- renderPlot(width = "auto", height = 640,{

        slice_year <- mydata[mydata$YEAR==input$slider_year,]
        map <- get_map(c(lon = -55.3632715, lat = 31.7632836), zoom = 3, source = 'google', maptype = c("terrain"), messaging = FALSE, color = 'color')
        world <- ggmap(map)
        world <- world + stat_density2d(data = slice_year, aes(x = WEST, y = NORTH, fill = ..level.., alpha = ..level..), show_guide = FALSE, geom = "polygon", na.rm = TRUE) + scale_fill_gradient(name="Density", low="maroon", high="yellow", guide = 'colorbar')
        plot(world)
    })
})

Thanks for the help.

Illative

Could you provide some more information? https://mcmap.net/q/40507/-how-to-make-a-great-r-reproducible-example – Upstart

Answer 1

I think you should be able to replace this:

sliderInput("slider_year", "YEAR:", 
            min = 2001, max = 2011, value = 2009, 
            format="####", locale="us"
)

with this:

tags$div(title="Click here to slide through years",
    sliderInput("slider_year", "YEAR:", 
                min = 2001, max = 2011, value = 2009, 
                format="####", locale="us"
    )
)

Greenhaw

Thank you very much for the quick reply. Shiny R is really cool. I am also using Google Motion Chart with Shiny. Can you please do one more favor for me by providing me a way to add/change tool-tip in there. I haven't shown anything in Ui.r and in server.r I put some codes like: output$view_gviz <- renderGvis({ chart <- gvisMotionChart(visdata, idvar="Storm", timevar="Year",......). Thank you once again for the help. – Illative

I will be grateful if anyone provides me with the hint for my another post, similar to this one: post – Illative

But is there a way to style the title so that it scrolls if the tooltip is larger than a certain size? – Limoges

The div tag sends the encapsulated input object onto another row. Is there a way of keeping it inline? For instance, using a tag other than div? – Dorothi

Answer 2

This is slightly easier and more elegant way.

library(shinyBS) # Additional Bootstrap Controls

## From ui.R: Adds a tooltip to element with inputId = "someInput" 
## with text, "This is an input.", that appears to the left on hover.
bsTooltip(id = "someInput", title = "This is an input", 
          placement = "left", trigger = "hover")

## From server.R: Add the same tooltip as above
addTooltip(session, id = "someInput", title = "This is an input.",
           placement = "left", trigger = "hover")

You can add the Tooltip in ui.R or server.R, Additional you can also use Popover.

Cuesta

I'm not sure adding another library is easier or more elegant, although shinyBS is still great. – Epistyle

Answer 3

Nowadays it's possible to wrap ggplot visualizations around plot_ly, and plotly has a native component (precissely named tootip) which will serve the purpose you're looking for:

Example taken from: https://plotly.com/ggplot2/interactive-tooltip/

library(plotly)
#install.packages("gapminder")
library(gapminder)

p <- ggplot(gapminder, aes(x = gdpPercap, y = lifeExp, color = continent, text =      paste("country:", country))) +
     geom_point(alpha = (1/3)) + scale_x_log10()  

fig <- ggplotly(p)

fig

Also, refer to: https://plotly-r.com/controlling-tooltips.html for a more detailed explanation.

Ragman