Example-Ruby-Client.md

+# gemfile
+
+```ruby
+source 'https://rubygems.org' 
+gem 'rest-client'
+gem 'json'
+```
+
+# Client
+
+```ruby
+#!/usr/bin/env ruby
+
+require 'rubygems'
+require 'rest_client'
+require 'json'
+
+$server = 'http://rest.ensembl.org'
+
+
+def get_variants(species, symbol)
+  genes = rest_get("/xrefs/symbol/#{species}/#{symbol}?object_type=gene")
+
+  raise "No genes for species '#{species}' and symbol '#{symbol}'" if genes.size == 0
+  return rest_get("/overlap/id/#{genes[0]['id']}?feature=variation")
+end
+
+
+def rest_get(url)
+  $request_counter ||= 0   # Initialise if unset
+  $last_request_time ||= 0 # Initialise if unset
+
+  # Rate limiting: Sleep for the remainder of a second since the last request on every third request
+  $request_counter += 1
+  if $request_counter == 15 
+    diff = Time.now - $last_request_time
+    sleep(1-diff) if diff < 1
+    $request_counter = 0
+  end
+  
+  begin
+    response = RestClient.get "#{$server}/#{url}", {:accept => :json}
+    
+    $last_request_time = Time.now
+    JSON.parse(response)
+  rescue RestClient::Exception => e
+    puts "Failed for #{url}! #{response ? "Status code: #{response}. " : ''}Reason: #{e.message}"
+    
+    # Sleep for specified number of seconds if there is a Retry-After header
+    if e.response.headers[:retry_after]
+      sleep(e.response.headers[:retry_after].to_f)
+      retry # This retries from the start of the begin block
+    else
+      abort("Quitting... #{e.inspect}")
+    end
+  end
+end
+
+
+species = 'human'
+symbol  = 'BRAF'
+
+get_variants(species, symbol).each do |variant|
+  puts "#{variant['seq_region_name']}:#{variant['start']}-#{variant['end']}:#{variant['strand']} ==> #{variant['ID']} (#{variant['consequence_type']})"
+end
+
+```
\ No newline at end of file