fixed #29

DESCRIPTION

@@ -2,7 +2,7 @@ Type: Package
 Package: gtfstools
 Title: General Transit Feed Specification (GTFS) Editing and Analysing
     Tools
-Version: 0.1.0.9039
+Version: 0.1.0.9040
 Authors@R: 
     c(person(given = "Daniel",
              family = "Herszenhut",

NEWS.md

@@ -2,11 +2,12 @@
 
 ## New features
 
-- `get_parent_station()`
 - New function `convert_stops_to_sf()`.
 - New function `convert_shapes_to_sf()`.
 - New function `filter_route_type()`.
 - New function `filter_route_id()`. 
+- New function `filter_trip_id()`. 
+- New function `get_parent_station()`
 - New parameters to `read_gtfs()`: `fields`, `skip` and `encoding`. The `warnings` parameter was flagged as deprecated.
 - New parameters to `write_gtfs()`: `files`, `standard_only` and `as_dir`. They substitute the previously existent `optional` and `extra`, which were flagged as deprecated. The `warnings` parameter was flagged as deprecated too.
 - Not exported: `copy_gtfs_diff_field_class()`, `convert_from_standard()`, `convert_to_standard()`
@@ -15,6 +16,7 @@
 
 - The `get_trip_speed()` and `set_trip_speed()` examples, tests and vignette bits now only run if `{lwgeom}` is installed. `{lwgeom}` is an `{sf}` "soft" dependency required by these functions, and is listed in `Suggests`. However, package checks would fail not so gracefully if it wasn't installed, which is now fixed.
 - Fixed a bug in which the `crs` passed to `get_trip_geometry()` would be assigned to the result without actually reprojecting it.
+- Changed the behaviour of `get_trip_geometry()` to not raise an error when the 'file' parameter is left untouched and the GTFS object doesn't contain either the shapes or the stop_times table. Closes [#29](https://github.com/ipeaGIT/gtfstools/issues/29).
 
 ## Notes
 

R/get_trip_geometry.R

@@ -1,27 +1,28 @@
 #' Get trip geometry
 #'
-#' Returns the geometry of each specified \code{trip_id}, based either on the
-#' \code{shapes} or the \code{stop_times} file (or both).
+#' Returns the geometry of each specified `trip_id`, based either on the
+#' `shapes` or the `stop_times` file (or both).
 #'
-#' @param gtfs A GTFS object as created by \code{\link{read_gtfs}}.
-#' @param trip_id A string vector including the \code{trip_id}s to have their
-#'   geometries generated. If \code{NULL} (the default), the function generates
-#'   geometries for every \code{trip_id} in the GTFS.
-#' @param file The file from which geometries should be generated. By default
-#'   uses both \code{shapes} and \code{stop_times}.
+#' @param gtfs A GTFS object.
+#' @param trip_id A character vector including the `trip_id`s to have their
+#'   geometries generated. If `NULL` (the default), the function generates
+#'   geometries for every `trip_id` in the GTFS.
+#' @param file A character vector specifying the file from which geometries
+#'   should be generated (either one of or both `shapes` and `stop_times`). If
+#'   `NULL` (the default), the function attemps to generate the geometries from
+#'   both files, but only raises an error if none of the files exist.
 #' @param crs The CRS of the resulting object, either as an EPSG code or as an
 #'   `crs` object. Defaults to 4326 (WGS 84).
 #'
-#' @return A \code{LINESTRING sf}.
+#' @return A `LINESTRING sf`.
 #'
 #' @section Details:
 #' The geometry generation works differently for the two files. In the case of
-#' \code{shapes}, the shape as described in the text file is converted to an
-#' \code{sf} object. For \code{stop_times} the geometry is the result of linking
-#' subsequent stops along a straight line (stops' coordinates are retrieved from
-#' the \code{stops} file). Thus, the resolution of the geometry when generated
-#' with \code{shapes} tends to be much higher than when created with
-#' \code{stop_times}.
+#' `shapes`, the shape as described in the text file is converted to an `sf`
+#' object. For `stop_times` the geometry is the result of linking subsequent
+#' stops along a straight line (stops' coordinates are retrieved from the
+#' `stops` file). Thus, the resolution of the geometry when generated with
+#' `shapes` tends to be much higher than when created with `stop_times`.
 #'
 #' @examples
 #' data_path <- system.file("extdata/spo_gtfs.zip", package = "gtfstools")
@@ -31,6 +32,10 @@
 #' trip_geometry <- get_trip_geometry(gtfs)
 #' head(trip_geometry)
 #'
+#' # the above is identical to
+#' trip_geometry <- get_trip_geometry(gtfs, file = c("shapes", "stop_times"))
+#' head(trip_geometry)
+#'
 #' trip_ids <- c("CPTM L07-0", "2002-10-0")
 #' trip_geometry <- get_trip_geometry(gtfs, trip_id = trip_ids)
 #' trip_geometry
@@ -39,20 +44,33 @@
 #' @export
 get_trip_geometry <- function(gtfs,
                               trip_id = NULL,
-                              file = c("shapes", "stop_times"),
+                              file = NULL,
                               crs = 4326) {
 
   checkmate::assert_class(gtfs, "dt_gtfs")
   checkmate::assert_character(trip_id, null.ok = TRUE)
-  checkmate::assert_names(file, subset.of = c("shapes", "stop_times"))
+  checkmate::assert_character(file, null.ok = TRUE)
   checkmate::assert(
     checkmate::check_numeric(crs),
     checkmate::check_class(crs, "crs"),
     combine = "or"
   )
 
+  if (!is.null(file))
+    checkmate::assert_names(file, subset.of = c("shapes", "stop_times"))
+
   # check if required fields and files exist
 
+  if (is.null(file)) {
+    file <- names(gtfs)
+    file <- file[file %chin% c("shapes", "stop_times")]
+
+    if (identical(file, character(0)))
+      stop(
+        "The GTFS object must have either a 'shapes' or a 'stop_times' table."
+      )
+  }
+
   if ("shapes" %in% file) {
 
     checkmate::assert(

codemeta.json

@@ -10,7 +10,7 @@
   "codeRepository": "https://github.com/ipeaGIT/gtfstools",
   "issueTracker": "https://github.com/ipeaGIT/gtfstools/issues",
   "license": "https://spdx.org/licenses/MIT",
-  "version": "0.1.0.9039",
+  "version": "0.1.0.9040",
   "programmingLanguage": {
     "@type": "ComputerLanguage",
     "name": "R",
@@ -233,7 +233,7 @@
       "sameAs": "https://CRAN.R-project.org/package=zip"
     }
   ],
-  "fileSize": "2527.683KB",
+  "fileSize": "2529.414KB",
   "contIntegration": "https://codecov.io/gh/ipeaGIT/gtfstools?branch=master",
   "developmentStatus": "https://lifecycle.r-lib.org/articles/stages.html",
   "keywords": [

tests/testthat/test-get_trip_geometry.R

@@ -175,7 +175,7 @@ test_that("returns the geometries created by the given 'file'", {
 
 test_that("outputs an 'sf' object with correct crs", {
 
-  # crs is WGs by default
+  # crs is WGS by default
 
   point <- sf::st_sfc(sf::st_point(c(0, 0)), crs = 4326)
 
@@ -281,3 +281,26 @@ test_that("returns empty sf if passed 'trip_id' isn't linked to a 'shape_id'", {
   expect_equal(nrow(sf_geom), 0)
 
 })
+
+# issue #29
+test_that("works correctly if 'file' is untouched and one file is missing", {
+  no_shapes <- read_gtfs(data_path)
+  no_shapes$shapes <- NULL
+  expect_s3_class(get_trip_geometry(no_shapes), "sf")
+  expect_true(all(get_trip_geometry(no_shapes)$origin_file == "stop_times"))
+
+  no_stop_times <- read_gtfs(data_path)
+  no_stop_times$stop_times <- NULL
+  expect_s3_class(get_trip_geometry(no_stop_times), "sf")
+  expect_true(all(get_trip_geometry(no_stop_times)$origin_file == "shapes"))
+
+  none_of_them <- read_gtfs(data_path)
+  none_of_them$shapes <- none_of_them$stop_times <- NULL
+  expect_error(
+    get_trip_geometry(none_of_them),
+    regexp = paste0(
+      "The GTFS object must have either a ",
+      "'shapes' or a 'stop_times' table\\."
+    )
+  )
+})