KangarooIT - Polymaps Rails Plugin

Polymaps is a Ruby on Rails plugin that will take your geocoded data and draw polygons on a google map with it!

Check out the official github page at: http://github.com/cornflakesuperstar/polymaps

Polymaps README:

= Polymaps - Ruby Polygon overlays for Google Maps

- http://www.kangarooit.com/polymaps/polymaps_rails_plugin.php
- http://groups.google.com/group/polymaps
- http://github.com/cornflakesuperstar/polymaps

== Description

Polymaps lets you overlay clickable polygons on top of a google map with your specified geo-coded regions.

== Example Code

class Country < ActiveRecord::Base
    has_many                  :regions
    validates_presence_of     :code       # eg. 'AU'
  end

class Region < ActiveRecord::Base
    belongs_to                :country
    has_many                  :points
    validates_presence_of     :name       # eg. 'Victoria'
  end

class Point < ActiveRecord::Base
    belongs_to :region
    validates_presence_of     :lat, :lng
  end

view.html.erb:
  <% country = Country.find_by_code("TW") -%>
  <% polygons = PolyMaps::Renderer.new(country.code, country.regions, 'points', 'document.location.href=\'/regions/show/#{region.id}\'' ) %>
  <html>
  <body onload="draw_polymap()">
  <div id="map_canvas" style="width:100%; height:400px;"></div>
  <script src="http://maps.google.com/maps?file=api&v=2&key=yourkey" type="text/javascript"></script>
  <script language="javascript"><!--
  <%= polygons.library_js %>

function draw_polymap() {
    var map = new GMap2(document.getElementById("map_canvas"));
    map.addControl(new GSmallMapControl());
    <%= polygons.js %>

}
  //--></script>
  </body>
  </html>

== Example Output
  <html>
  <body onload="draw_polymap()">
  <div id="map_canvas" style="width:100%; height:400px;"></div>
  <script src="http://maps.google.com/maps?file=api&v=2&key=yourkey" type="text/javascript"></script>
  <script language="javascript"><!--
  //...include js

== Usage Doc

<% polygons = PolyMaps::Renderer.new(country_code, regions_collection, relationship_name, onclick_handler, polygon_limit) -%>
<%= polygons.js %>

@param country_code consisting of two letters and complying to the ISO 3166-1 
    alpha-2 standard

@param regions_collection objects will be checked for a 'name' attribute which 
    will display as the polygon label (if it exists)

@param relationship_name refers to the region objects relationship name specifying
    the child 'ordinate' objects (which must each have a 'lat' and 'lng' attribute)

@param onclick_handler will be interpreted and assumes a 'region' object will be 
    in scope

@param polygon_limit (optional) can be set to limit the number of polygons that are rendered for javascript
  	performance purposes (you don't really want a gazillion points being rendered on your map do you?)

== Troubleshooting

Check your console for 'Polymaps Unsupported country code: ..' messages. The lib/country_centers_and_zooms.yml needs more data 
(I use http://www.kangarooit.com/developer_blog/hover_lat_lng.html to get this data by plotting a rectangle around each country)

If you install as a gem, make sure the require statement has an underscore in the name (require "poly_maps" )

== Install for Rails

First, ensure that you’re running at least RubyGems 1.2 (check gem -v if you’re not sure).

The polymaps gem is built by GitHub. Add GitHub to your gem sources (once per machine):

gem sources -a http://gems.github.com

Install the library:

gem install cornflakesuperstar-polymaps

To enable the library, load it at the end of “config/environment.rb”

require "poly_maps"

To install the latest code as a plugin:

script/plugin install git://github.com/cornflakesuperstar/polymaps.git

== Authors

- Developed by {Jason Kotchoff}[http://www.kangarooit.com/contact_us.php]

== License

Example Polymaps output: