/armg

Add MySQL geometry type to Active Record.

Primary LanguageRubyMIT LicenseMIT

Armg

Add MySQL geometry type to Active Record.

Gem Version Build Status

Installation

Add this line to your application's Gemfile:

gem 'armg'

And then execute:

$ bundle

Or install it yourself as:

$ gem install armg

Usage

require 'active_record'
require 'armg'

ActiveRecord::Base.establish_connection(adapter: 'mysql2', database: 'my_db')

ActiveRecord::Migration.create_table :geoms, options: 'ENGINE=MyISAM' do |t|
  t.geometry 'location', null: false
  t.index ['location'], name: 'idx_location', type: :spatial
end

class Geom < ActiveRecord::Base; end

wkt_parser = RGeo::WKRep::WKTParser.new(nil, support_ewkt: true)
point = wkt_parser.parse('SRID=4326;Point(-122.1 47.3)')
Geom.create!(location: point)

Geom.first
#=> #<Geom id: 1, location: #<RGeo::Cartesian::PointImpl:0x... "POINT (-122.1 47.3)">>

Using WKT

Armg.deserializer = Armg::WktDeserializer.new
Armg.serializer = Armg::WktSerializer.new

Geom.create!(location: 'Point(-122.1 47.3)')

Geom.first
#=> #<Geom id: 1, location: "Point (-122.1 47.3)">

Using custom deserializer

class CustomDeserializer
  def initialize
    factory = RGeo::Geographic.spherical_factory(srid: 0)
    @wkb_parser = RGeo::WKRep::WKBParser.new(factory, support_ewkb: true)
  end

  def deserialize(wkb)
    wkb_without_srid = wkb.b.slice(4..-1)
    @wkb_parser.parse(wkb_without_srid)
  end
end

Armg.deserializer = CustomDeserializer.new

Geom.take
#=> #<Geom id: 1, location: #<RGeo::Geographic::SphericalPointImpl:0x... "POINT (-122.1 47.3)">>

Using custom serializer

class CustomSerializer
  def initialize
    @wkt_parser = RGeo::WKRep::WKTParser.new(nil, support_ewkt: true)
    @wkb_generator = RGeo::WKRep::WKBGenerator.new(type_format: :ewkb, little_endian: true)
  end

  def serialize(value)
    if value.is_a?(String)
      value = @wkt_parser.parse(value)
    end

    srid = "\x00\x00\x00\x00"
    srid + @wkb_generator.generate(value)
  end
end

Armg.serializer = CustomSerializer.new

Geom.create!(id: 4, location: 'Point(-122.1 47.3)')

Running tests

docker-compose up -d
bundle install
bundle exec appraisal install
bundle exec appraisal ar61 rake
# bundle exec appraisal ar60 rake
# ARMG_TEST_MYSQL_PORT=10057 bundle exec appraisal ar61 rake # MySQL 5.7
# ARMG_TEST_MYSQL_PORT=10057 ARMG_TEST_MYSQL_ENGINE=InnoDB bundle exec appraisal ar61 rake

Using with Ridgepole

You need to extend the TableDefinition class.

# ridgepole-geo.rb
module TableDefinitionExtForGeometry
  def geometry(*args)
    options = args.extract_options!
    column_names = args
    column_names.each { |name| column(name, :geometry, options) }
  end
end
Ridgepole::DSLParser::TableDefinition.prepend(TableDefinitionExtForGeometry)

module DiffExtForGeometry
  def normalize_index_options!(opts)
    super
    opts.delete(:length) if opts[:type] == :spatial
  end
end
Ridgepole::Diff.prepend(DiffExtForGeometry)
$ ridgepole -c 'mysql2://root@127.0.0.1:10057/armg_test' -r armg -e > Schemafile

$ cat Schemafile
# Export Schema
create_table "geoms", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
  t.geometry "location", null: false
  t.string "name"
  t.index ["location"], name: "idx_location", length: 32, type: :spatial
  t.index ["name"], name: "idx_name", length: 10
end

$ ridgepole -c 'mysql2://root@127.0.0.1:10057/armg_test' -r armg,ridgepole-geo -a
Apply `Schemafile`
No change

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