How do I render a shiny map in rmarkdown

[pssguy]

Hi
I have no problems creating a static leafletmap in rMarkdown. However I'm not sure how to render one where there is an input variable. This approach creates the data OK but does not render map.

observe({

data <- calcs involving input$var

glimpse(data) # confirmscorrect values in console

leaflet(data) %>%
addTiles() %>%
addCircleMarkers(info based on data)

})

should I be using renderLeaflet somehow or adding a binding similar to that used for ggvis in rMarkdown

[yihui]

It is just like all traditional Shiny output elements, i.e. use leafletOutput(id) in ui.R, and output$id = renderLeaflet(leaflet() %>% addTiles() %>% ...) in server.R.

[pssguy]

I was hoping to code directly in Rmarkdown without the need to wrap it in an embedded shinyApp
That is my normal practice if I want to display dataTables or ggvis plots, for example
However, it is no big deal as I have gone the embedding route and seems to work fine

[yihui]

I think you can just replace observe() with renderLeaflet().

[jjallaire]

I think you just need to add runtime: shiny to the YAML and then you can use leaflet in reactives. It would be something like this:

renderLeaflet({

   data <- calcs involving input$var

   glimpse(data) # confirmscorrect values in console

   leaflet(data) %>% 
      addTiles() %>% 
      addCircleMarkers(info based on data)

})

@yihui does that look right?

[yihui]

@jjallaire Exactly. Here is a minimal example:

---
output: html_document
runtime: shiny
---

Test leaflet

```{r}
library(leaflet)
library(shiny)
sliderInput('n', 'Number of markers', min = 1, max = 100, value = 30, step = 1)
renderLeaflet({
  n = input$n
  df = data.frame(lat = rnorm(n, 42), lng = rnorm(n, -93))
  leaflet(df) %>% addTiles() %>% addMarkers()
})
```

[pssguy]

Thanks for assistance