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Drop any NULL coordinates from a GeoJSON geometry.

Source: R/drop_null_coords.R
drop_null_coords.Rd

This helper patches a bug/feature in ODK Central (versions 0.7-0.9), where geotrace / geoshape GeoJSON contains a last coordinate pair with NULL lat/lon (no alt/acc), and WKT ends in , undefined NaN.

Usage

drop_null_coords(x)

Arguments

x

A GeoJSON geometry parsed as nested list. E.g. geo_gj$path_location_path_gps.

Value

The nested list minus the last element (if NULL).

Details

While split_geotrace and split_geoshape modify the WKT inline, it is more maintainable to separate the GeoJSON cleaner into this function.

This helper drops the last element of a GeoJSON coordinate list if it is list(NULL, NULL).

See also

Other utilities: attachment_get(), attachment_link(), attachment_url(), form_schema_parse(), get_one_attachment(), get_one_submission(), get_one_submission_att_list(), get_one_submission_audit(), handle_ru_attachments(), handle_ru_datetimes(), handle_ru_geopoints(), handle_ru_geoshapes(), handle_ru_geotraces(), isodt_to_local(), odata_submission_rectangle(), predict_ruodk_name(), prepend_uuid(), split_geopoint(), split_geoshape(), split_geotrace(), strip_uuid(), tidyeval, unnest_all()

Examples

# A snapshot of geo data with trailing empty coordinates.
data("geo_gj88")

len_coords <- length(geo_gj88$path_location_path_gps[[1]]$coordinates)

length(geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]]) %>%
  testthat::expect_equal(2)

geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]][[1]] %>%
  testthat::expect_null()

geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]][[2]] %>%
  testthat::expect_null()

# The last coordinate pair is a list(NULL, NULL).
# Invalid coordinates like these are a choking hazard for geospatial
# packages. We should remove them before we can convert ODK data into native
# spatial formats, such as sf.
str(geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]])
#> List of 2
#>  $ : NULL
#>  $ : NULL

geo_gj_repaired <- geo_gj88 %>%
  dplyr::mutate(
    path_location_path_gps = path_location_path_gps %>%
      purrr::map(drop_null_coords)
  )

len_coords_repaired <- length(
  geo_gj_repaired$path_location_path_gps[[1]]$coordinates
)
testthat::expect_equal(len_coords_repaired + 1, len_coords)