Convert spatial data files to GeoJSON from various formats.
Source:R/file_to_geojson.r
file_to_geojson.Rd
You can use a web interface called Ogre, or do conversions locally using the sf package.
Usage
file_to_geojson(
input,
method = "web",
output = ".",
parse = FALSE,
encoding = "CP1250",
verbose = FALSE,
...
)
Arguments
- input
The file being uploaded, path to the file on your machine.
- method
(character) One of "web" (default) or "local". Matches on partial strings. This parameter determines how the data is read. "web" means we use the Ogre web service, and "local" means we use sf. See Details fore more.
- output
Destination for output geojson file. Defaults to current working directory, and gives a random alphanumeric file name
- parse
(logical) To parse geojson to data.frame like structures if possible. Default:
FALSE
- encoding
(character) The encoding passed to
sf::st_read()
. Default: CP1250- verbose
(logical) Printing of
sf::st_read()
progress. Default:FALSE
- ...
Additional parameters passed to
st_read
Method parameter
The web option uses the Ogre web API. Ogre currently has an output size
limit of 15MB. See here http://ogre.adc4gis.com/ for info on the
Ogre web API. The local option uses the function st_write
from the package rgdal.
Ogre
Note that for Shapefiles, GML, MapInfo, and VRT, you need to send zip files to Ogre. For other file types (.bna, .csv, .dgn, .dxf, .gxt, .txt, .json, .geojson, .rss, .georss, .xml, .gmt, .kml, .kmz) you send the actual file with that file extension.
Linting GeoJSON
If you're having trouble rendering GeoJSON files, ensure you have a valid GeoJSON file by running it through the package geojsonlint, which has a variety of different GeoJSON linters.
File size
When using method="web"
, be aware of file sizes.
https://ogre.adc4gis.com that we use for this option does not document
what file size is too large, but you should get an error message like
"maximum file length exceeded" when that happens. method="local"
shouldn't be sensitive to file sizes.
Examples
if (FALSE) { # \dontrun{
file <- system.file("examples", "norway_maple.kml", package = "geojsonio")
# KML type file - using the web method
file_to_geojson(input = file, method = "web", output = "kml_web")
## read into memory
file_to_geojson(input = file, method = "web", output = ":memory:")
file_to_geojson(input = file, method = "local", output = ":memory:")
# KML type file - using the local method
file_to_geojson(input = file, method = "local", output = "kml_local")
# Shp type file - using the web method - input is a zipped shp bundle
file <- system.file("examples", "bison.zip", package = "geojsonio")
file_to_geojson(file, method = "web", output = "shp_web")
# Shp type file - using the local method - input is the actual .shp file
file <- system.file("examples", "bison.zip", package = "geojsonio")
dir <- tempdir()
unzip(file, exdir = dir)
list.files(dir)
shpfile <- file.path(dir, "bison-Bison_bison-20130704-120856.shp")
file_to_geojson(shpfile, method = "local", output = "shp_local")
# geojson with .json extension
## this doesn't work anymore, hmmm
# x <- gsub("\n", "", paste0('https://gist.githubusercontent.com/hunterowens/
# 25ea24e198c80c9fbcc7/raw/7fd3efda9009f902b5a991a506cea52db19ba143/
# wards2014.json', collapse = ""))
# res <- file_to_geojson(x)
# jsonlite::fromJSON(res)
# res <- file_to_geojson(x, method = "local")
# jsonlite::fromJSON(res)
} # }