Merge pull request #2 from asiripanich/0.3.0

0.3.0

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: tfnswapi
 Type: Package
 Title: Access TfNSW Open Data from R
-Version: 0.2.0
+Version: 0.3.0
 Author: Amarin Siripanich
 Maintainer: Amarin Siripanich <[email protected]>
 Description: Access TfNSW Open Data from R.

NEWS.md

@@ -1,3 +1,7 @@
+# tfnswapi 0.3.0
+
+* Added the ability to specific which protobuf descriptor `tfnswapi_get()` will use to parse a 'application/x-google-protobuf' response. You can select one of `transit_realtime.*` variables, `transit_realtime.FeedMessage` is selected as default.
+
 # tfnswapi 0.2.0
 
 * You now can quickly browse TfNSW API with `tfnswapi_browse()`.

R/get.R

@@ -9,6 +9,9 @@ tfnsw_base_api_url = "https://api.transport.nsw.gov.au/"
 #'  here.
 #' @param key Character (optional). An API key can be provided, else if emptied
 #'  it will look for any previously registered API key.
+#' @param descriptor This field is only used if the response is of type
+#'  `application/x-google-protobuf`. You must select one of `transit_realtime` variables.
+#'  By default this is `transit_realtime.FeedMessage`.
 #'
 #' @return a response with parsed content.
 #' @export
@@ -22,18 +25,21 @@ tfnsw_base_api_url = "https://api.transport.nsw.gov.au/"
 #'  tfnswapi_get("carpark", params = list(facility = 2))
 #'
 #' }
-tfnswapi_get = function(api, params = NULL, key = tfnswapi_get_api_key()) {
+tfnswapi_get = function(api,
+                        params = NULL,
+                        key = tfnswapi_get_api_key(),
+                        descriptor = transit_realtime.FeedMessage) {
 
-  checkmate::assert_string(api)
-
-  path = glue::glue("v1/{api}")
+  path = construct_path(api)
 
   response = tfnswapi_get_response(path, params, key)
 
-  response$content = switch(httr::http_type(response),
-                  "application/json" = parse_json_response(response),
-                  "application/x-google-protobuf" = parse_ggprotobuf_response(response),
-                  stop("Don't know how to parse ", httr::http_type(response)))
+  response$content = switch(
+    httr::http_type(response),
+    "application/json" = parse_json_response(response),
+    "application/x-google-protobuf" = parse_ggprotobuf_response(response, descriptor),
+    stop("Don't know how to parse ", httr::http_type(response))
+  )
 
   if (httr::status_code(response) != 200) {
     stop(
@@ -74,9 +80,13 @@ parse_json_response = function(response) {
   jsonlite::fromJSON(httr::content(response, "text"), simplifyVector = FALSE)
 }
 
-parse_ggprotobuf_response = function(response) {
-  FeedMessage = RProtoBuf::read(descriptor = transit_realtime.FeedMessage,
-                                input = response$content)
+parse_ggprotobuf_response = function(response, descriptor = transit_realtime.FeedMessage) {
+  FeedMessage = RProtoBuf::read(descriptor = descriptor, input = response$content)
   json = RProtoBuf::toJSON(FeedMessage)
   lst = jsonlite::fromJSON(json)
 }
+
+construct_path = function(api) {
+  checkmate::assert_string(api)
+  glue::glue("v1/{api}")
+}

README.Rmd

@@ -16,7 +16,6 @@ knitr::opts_chunk$set(
 # tfnswapi
 
 <!-- badges: start -->
-[![Lifecycle: experimental](https://img.shields.io/badge/lifecycle-experimental-orange.svg)](https://www.tidyverse.org/lifecycle/#experimental)
 [![R build status](https://github.com/asiripanich/tfnswapi/workflows/R-CMD-check/badge.svg)](https://github.com/asiripanich/tfnswapi/actions)
 <!-- badges: end -->
 
@@ -34,9 +33,11 @@ You can install the `tfnswapi` package from [GitHub](https://github.com/asiripan
 install.packages("tfnswapi")
 ```
 
-## Example
+## Examples
 
-```{r example}
+### Carpark API
+
+```{r carpark-example, dpi=300}
 library(tfnswapi)
 # See what facilities are available
 
@@ -68,3 +69,43 @@ ggplot(data = tidied_carpark, aes(x = zone_id)) +
     y = "# Spots"
   )
 ```
+### GTFS Realtime API
+
+See TfNSW GTFS Realtime documentation [here](https://opendata.transport.nsw.gov.au/sites/default/files/TfNSW_GTFS_Realtime_Buses_Technical_Doc.pdf).
+
+```{r gtfsr-example, dpi=300, message=FALSE}
+library(tfnswapi)
+library(ggplot2)
+library(ggmap)
+library(sf)
+
+# remove `if (FALSE)` to register your own API key
+if (FALSE) {
+  tfnswapi_register("<your-api-key>")
+}
+
+bus_response = tfnswapi_get("gtfs/vehiclepos/buses")
+bus_position_table = bus_response$content$entity$vehicle$position
+
+bus_position_table = 
+  bus_position_table %>%
+  sf::st_as_sf(coords = c("longitude", "latitude")) %>%
+  sf::st_set_crs(value = sf::st_crs("WGS84"))
+
+# Convert momentary speed measured by the vehicle in meters per second to
+# kilometers per hour
+bus_position_table$speed = 3.6 * bus_position_table$speed
+
+# get base map
+sydney_bbox = sf::st_geometry(bus_position_table) %>% sf::st_bbox()
+names(sydney_bbox) <- c("left", "bottom", "right", "top")
+sydney_map = get_stamenmap(sydney_bbox, maptype = "toner-lite", messaging = FALSE)
+
+ggmap(sydney_map) +
+  coord_sf(crs = sf::st_crs("WGS84")) +
+  geom_sf(data = bus_position_table, aes(color = speed), inherit.aes = FALSE) +
+  labs(title = "Realtime positions of buses in Sydney, Australia",
+       color = "Speed (km/hr)",
+       subtitle = bus_response$date)
+```
+

README.md

@@ -5,8 +5,6 @@
 
 <!-- badges: start -->
 
-[![Lifecycle:
-experimental](https://img.shields.io/badge/lifecycle-experimental-orange.svg)](https://www.tidyverse.org/lifecycle/#experimental)
 [![R build
 status](https://github.com/asiripanich/tfnswapi/workflows/R-CMD-check/badge.svg)](https://github.com/asiripanich/tfnswapi/actions)
 <!-- badges: end -->
@@ -29,7 +27,9 @@ You can install the `tfnswapi` package from
 install.packages("tfnswapi")
 ```
 
-## Example
+## Examples
+
+### Carpark API
 
 ``` r
 library(tfnswapi)
@@ -76,4 +76,46 @@ ggplot(data = tidied_carpark, aes(x = zone_id)) +
   )
 ```
 
-<img src="man/figures/README-example-1.png" width="100%" />
+<img src="man/figures/README-carpark-example-1.png" width="100%" />
+\#\#\# GTFS Realtime API
+
+See TfNSW GTFS Realtime documentation
+[here](https://opendata.transport.nsw.gov.au/sites/default/files/TfNSW_GTFS_Realtime_Buses_Technical_Doc.pdf).
+
+``` r
+library(tfnswapi)
+library(ggplot2)
+library(ggmap)
+library(sf)
+
+# remove `if (FALSE)` to register your own API key
+if (FALSE) {
+  tfnswapi_register("<your-api-key>")
+}
+
+bus_response = tfnswapi_get("gtfs/vehiclepos/buses")
+bus_position_table = bus_response$content$entity$vehicle$position
+
+bus_position_table = 
+  bus_position_table %>%
+  sf::st_as_sf(coords = c("longitude", "latitude")) %>%
+  sf::st_set_crs(value = sf::st_crs("WGS84"))
+
+# Convert momentary speed measured by the vehicle in meters per second to
+# kilometers per hour
+bus_position_table$speed = 3.6 * bus_position_table$speed
+
+# get base map
+sydney_bbox = sf::st_geometry(bus_position_table) %>% sf::st_bbox()
+names(sydney_bbox) <- c("left", "bottom", "right", "top")
+sydney_map = get_stamenmap(sydney_bbox, maptype = "toner-lite", messaging = FALSE)
+
+ggmap(sydney_map) +
+  coord_sf(crs = sf::st_crs("WGS84")) +
+  geom_sf(data = bus_position_table, aes(color = speed), inherit.aes = FALSE) +
+  labs(title = "Realtime positions of buses in Sydney, Australia",
+       color = "Speed (km/hr)",
+       subtitle = bus_response$date)
+```
+
+<img src="man/figures/README-gtfsr-example-1.png" width="100%" />