Ruby Array extension in order to render as geoJSON using the rgeo-geojon gem

README.md

Ruby Array to_geojson

####Dependencies

• rgeo
• rgeo-geojson

####Usage Add geojson_renderer.rb file into config/initializers folder Add array.rb file in /lib/core_ext folder Add require 'core_ext/array.rb' in environment.rb

call render :geojson => @objects from controller

• assumes id will be used for the feature id
• assumes geom will be used for the geometry field
• :only and :except act same as render :json => @objects

####Future add add_methods option

thanks to @beerlington for his inpiration from this post-rails-3/

arrray.rb

class Array
  def to_geojson(options={})
		features = Array.new

		fields = first.attributes.keys
		fields -= ['id', 'geom']
		fields &= options[:only].map(&:to_s) if options[:only]
		fields -= options[:except].map(&:to_s) if options[:except]

		self.each do |feature|
			properties = Hash[fields.map {|f| [f, feature[f]]}]
			features<<RGeo::GeoJSON::Feature.new(feature.geom, feature.id, {date: feature.date_time})
		end

		featureCollection = RGeo::GeoJSON::FeatureCollection.new(features)
		RGeo::GeoJSON.encode(featureCollection).to_json
	end
end

geojson_renderer.rb

require 'action_controller/metal/renderers'

ActionController.add_renderer :geojson do |geojson, options|
  self.response_body = geojson.respond_to?(:to_geojson) ? geojson.to_geojson(options) : geojson
end

add better error checking