Adding a provider_zones object to the package

The first and hardest step is to create an sf object analogous to the test_zones object shown below:

names(test_zones)
#> [1] "id"            "name"          "parent"        "level"        
#> [5] "pbf_file_size" "pbf"           "geometry"
str(test_zones[, c(2, 6, 7)])
#> Classes 'sf' and 'data.frame':   2 obs. of  3 variables:
#>  $ name    : chr  "Isle of Wight" "ITS Leeds"
#>  $ pbf     : chr  "https://github.com/ropensci/osmextract/releases/download/0.0.1/geofabrik_isle-of-wight-latest.osm.pbf" "https://github.com/ropensci/osmextract/raw/master/inst/its-example.osm.pbf"
#>  $ geometry:sfc_POLYGON of length 2; first list element: List of 1
#>   ..$ : num [1:7, 1:2] -1.52 -1.66 -1.31 -1.11 -1.03 ...
#>   ..- attr(*, "class")= chr [1:3] "XY" "POLYGON" "sfg"
#>  - attr(*, "sf_column")= chr "geometry"
#>  - attr(*, "agr")= Factor w/ 3 levels "constant","aggregate",..: NA NA
#>   ..- attr(*, "names")= chr [1:2] "name" "pbf"

The output shows the three most important column names:

1. The zone name (that is used for matching the input place, see oe_match());
2. The URL endpoint where .pbf files associated with each zone can be downloaded;
3. The geometry, representing the spatial extent of the dataset.

The object must also include the fields level and id, which are used, respectively, for spatial matching and updating. See oe_match() and oe_update().

The best way to start creating a new _zones object for a new provider is probably by looking at the code we wrote for the first supported provider in data-raw/geofabrik_zones.R. The following commands will clone this repo and open the relevant file:

git clone git@github.com:ropensci/osmextract
rstudio osmextract/osmextract.Rproj

Then in RStudio:

file.edit("data-raw/geofabrik_zones.R")

Create a new script to document the code that generates the new object, e.g. for bbbike:

file.edit("data-raw/bbbike_zones.R")
# or, even better, use
usethis::use_data_raw("bbbike_zones")

After you have created the new provider _zones file, it’s time to add the provider to the package.

Adding the new provider to the package

Once you have created your overview _zones file as outlined in the previous step, you need to modify the following files for the provider to be available for others:

• data.R, where you’ll need to document the new dataset;
• globals.R, where you’ll need to add the new object name;
• providers.R, where you’ll need to add the new object name in oe_available_providers() and load_provider_data().

Documenting the provider

The final step is also the most fun: documenting and using the provider. Add an example, mention it in the README and tell others about what this new provider can do! If you want to ask for help on adding a new provider, feel free to open in a new issue in the github repository!

Conclusion

This vignette talks through the main steps needed to extend osmextract by adding new OSM data providers. To see the same information in code form, see the PR that implemented the openstreetmap_fr provider here: https://github.com/ropensci/osmextract/commit/dbf131667a80e5a6837a6c8eb3b967075e1aba16