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rgeospatialgeojson

Create single column GeoJSON using R

I am trying to create an excel file, ready for use within Power Apps Geospatial features: https://learn.microsoft.com/en-us/power-apps/maker/canvas-apps/geospatial-map-draw-shapes#import-geojson-shapes-into-a-map

This needs a single excel file, where each row is a seperate feature, which has a GeoJSON column which is a self contained GeoJSON object.

I can't work out how to do this using R and R Studio. My input file is a GeoJSON, but could be a shapefile.

I have tried a number of methods, but on each occasion I am tripping up with trying to get the features to export

Solution

  • Through brute force trying only, I've found a way to do this:

    # Load the required library
library(sf)
library(geojsonsf)
library(jsonlite)
library(dplyr)
library(openxlsx)

# Set column name so it can be easily amended for different files.
# Could replace this with extraction from GeoJSON?
colnameselect <- ""

# Read the GeoJSON file
geojson <- st_read("input.geojson")

# Simplify the file to a 100m resolution
shp_simpl <- st_simplify(geojson, 
                         preserveTopology = FALSE, 
                         dTolerance = 100)


geojson_new <- sf_geojson(shp_simpl, atomise = T)

geojson_new_unlist <- lapply(geojson_new, unlist)

geojson_df <- do.call(rbind.data.frame, geojson_new_unlist)
names(geojson_df)[1] <- "GeoJSON"

shp_join <- shp_simpl %>% select(all_of(colnameselect))
shp_join <- st_drop_geometry(shp_join)

join_list <- cbind(shp_join,geojson_df)

openxlsx::write.xlsx(join_list, "test_Geojson.xls")

    This seems to do the job! Thanks to everyone for their help - lots of different ideas all helped me sort it out. Particularly the unlisting of the GeoJSON