geojsonio (version 0.8.0)

file_to_geojson: Convert spatial data files to GeoJSON from various formats.

Description

You can use a web interface called Ogre, or do conversions locally using the rgdal 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 rgdal. 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 rgdal::readOGR(). Default: CP1250

verbose

(logical) Printing of rgdal::readOGR() progress. Default: FALSE

...

Additional parameters passed to readOGR

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 writeOGR 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

# NOT RUN {
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')

# Neighborhoods in the US
## beware, this is a long running example
# url <- 'http://www.nws.noaa.gov/geodata/catalog/national/data/ci08au12.zip'
# out <- file_to_geojson(input=url, method='web', output='cities')

# 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)
# }

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