_06-shiny.Rmd

# Shiny interactive map applications {#shiny}

Use of the shiny package to make interactive applications displaying maps.

We start with a very simple example showing how you can create a small application that allows a user to choose from a list of countries and then displays the outline of that country on a map.

[andy (or anyone else) to look at best ways of demoing shinyapps in a book]

```{r shiny1, eval=FALSE}

# save this code in a single file called app.r
# then the shiny app can be run from RStudio using the 'Run' button
# (above the text editor window)
# or can just copy & paste code into the console

library(afrilearndata)
library(dplyr)
library(mapview)
library(leaflet)

# User Interface
ui <- bootstrapPage(
  
  # allow user to choose a country 
  selectInput('country_choice', 
              label='choose a country', 
              choices = sort(africountries$name)),
  # plot map
  leafletOutput("serve_map")
)

# server code (does things requested by the UI)
server <- function(input, output) {
  
  output$serve_map <- renderLeaflet({
    
    # filter
    selected_country <- dplyr::filter(africountries, name==input$country_choice) 
    mapplot <- mapview(selected_country, zcol="name")
    mapplot@map
    
  })
}

# Return a Shiny app object
shinyApp(ui = ui, server = server)

```

## Further resources

## Summary

## Exercise solutions {#solutions_ch5}