Merge pull request #22 from mrnugget/api_readme

Add basic API usage information to README

README.rdoc

@@ -6,6 +6,39 @@ Works with Ruby 1.8.7, 1.9.x. and 2.0.x.
 
 {<img src="https://travis-ci.org/Graylog2/gelf-rb.png?branch=master" alt="Build Status" />}[https://travis-ci.org/Graylog2/gelf-rb]
 
+== Usage
+=== Gelf::Notifier
+
+This allows you to sent arbitary messages via UDP to your Graylog2 server.
+
+  n = GELF::Notifier.new("localhost", 12201)
+
+  # Send with custom attributes and an additional parameter "foo"
+  n.notify!(:short_message => "foo", :full_message => "something here\n\nbacktrace?!", :_foo => "bar")
+
+  # Pass any object that responds to .to_hash
+  n.notify!(Exception.new)
+
+=== Gelf::Logger
+
+The Gelf::Logger is compatible with the standard Ruby Logger interface and can be used interchangeably.
+Under the hood it uses Gelf::Notifier to send log messages via UDP to Graylog2.
+
+  logger = GELF::Logger.new("localhost", 12201, "WAN", { :facility => "appname" })
+
+  logger.debug "foobar"
+  logger.info "foobar"
+  logger.warn "foobar"
+  logger.error "foobar"
+  logger.fatal "foobar"
+
+  logger << "foobar"
+
+Since it's compatible with the Logger interface, you can also use it in your Rails application:
+
+  # config/environments/production.rb
+  config.logger = GELF::Logger.new("localhost", 12201, "WAN", { :facility => "appname" })
+
 == Note on Patches/Pull Requests
 
 * Fork the project.