example_leaftime.R

if(interactive()) {

library(leaflet)
library(leaftime)
library(htmltools)

#Build data.frame with 10 obs + 3 cols
power <- data.frame(
  "Latitude" = c(
    33.515556, 38.060556, 47.903056, 49.71, 49.041667, 31.934167,
    54.140586, 54.140586, 48.494444, 48.494444
  ),
  "Longitude" = c(
    129.837222, -77.789444, 7.563056, 8.415278, 9.175, -82.343889,
    13.664422, 13.664422, 17.681944, 17.681944
  ),
  "start" = seq.Date(as.Date("2015-01-01"), by = "day", length.out = 10),
  "end" = seq.Date(as.Date("2015-01-01"), by = "day", length.out = 10) + 1
)

# use geojsonio to convert our data.frame
#  to GeoJSON which timeline expects
power_geo <- geojsonio::geojson_json(power,lat="Latitude",lon="Longitude")

# we can add data in addTimeline
leaflet() %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(data = power_geo)

# or we can add data in leaflet()
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline()

# we can control the slider controls through sliderOptions
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    sliderOpts = sliderOptions(
      formatOutput = htmlwidgets::JS(
        "function(date) {return new Date(date).toDateString()}
      "),
      position = "bottomright",
      step = 10,
      duration = 3000,
      showTicks = FALSE
    )
  )

# we can control the timeline through timelineOptions
#  wondering what should be the default
#  currently timeline uses marker
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    timelineOpts = timelineOptions(
      pointToLayer = htmlwidgets::JS(
"
function(data, latlng) {
  return L.circleMarker(latlng, {
    radius: 3
  })
}
"
      ),
      style = NULL
    )
  )

# change styling manually
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    timelineOpts = timelineOptions(
      pointToLayer = htmlwidgets::JS(
"
function(data, latlng) {
  return L.circleMarker(latlng, {
    radius: 10,
    color: 'black',
    fillColor: 'pink',
    fillOpacity: 1
  })
}
"
      ),
      styleOptions = NULL
    )
  )

# change style with styleOptions helper function
#   this will change style for all points
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    timelineOpts = timelineOptions(
      styleOptions = styleOptions(
        radius = 10,
        color = "black",
        fillColor = "pink",
        fillOpacity = 1
      )
    )
  )

# to style each point differently based on the data
power_styled <- power
# IE does not like alpha so strip colors of alpha hex
power_styled$color <- substr(topo.colors(6)[ceiling(runif(nrow(power),0,6))],1,7)
power_styled$radius <- seq_len(nrow(power_styled)) # ceiling(runif(nrow(power),3,10))

leaflet(geojsonio::geojson_json(power_styled)) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  # addCircleMarkers(
  #   data = power_styled, lat = ~Latitude, lng = ~Longitude, radius = 11
  # ) %>%
  addTimeline(
    timelineOpts = timelineOptions(
      styleOptions = NULL, # make sure default style does not override
      pointToLayer = htmlwidgets::JS(
"
function(data, latlng) {
  return L.circleMarker(
    latlng,
    {
      radius: +data.properties.radius,
      color: data.properties.color,
      fillColor: data.properties.color,
      fillOpacity: 1
    }
  );
}
"
      )
    )
  )



# we can use onchange to handle timeline change event
leaflet(power_geo) %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    onchange = htmlwidgets::JS("function(e) {console.log(e, arguments)}")
  )


leaflet(power_geo, elementId = "leaflet-wide-timeline") %>%
  addTiles() %>%
  setView(44.0665,23.74667,2) %>%
  addTimeline(
    width = "96%"
  )

}