@@ -2,40 +2,64 @@ == DESCRIPTION -ignore_nil lets you happily ignore nil methods on long method chains. Keeps code pretty and much safer than "rescue nil", since it only catches NoMethodError on nil objects. +ignore_nil lets you happily ignore nil methods on long method chains. Keeps code pretty and much +safer than "rescue nil", since it only catches NoMethodError on nil objects. -ignore_nil {} will either return the last thing evaluated in the block, or nil if a NoMethodError is raised calling a method on a nil object. Any other exceptions raised in the block are not handled, and left for the application to resolve. +ignore_nil {} will either return the last thing evaluated in the block, or nil if a NoMethodError +is raised calling a method on a nil object. Any other exceptions raised in the block are not handled, +and left for the application to resolve. More details below. == INSTALLATION as a gem: - sudo gem install ssoroka-ignore_nil + + sudo gem install ssoroka-ignore_nil as a plugin: - script/plugin install git://github.com/ssoroka/ignore_nil.git + + script/plugin install git://github.com/ssoroka/ignore_nil.git == USAGE - ignore_nil { user.profile.photo } + ignore_nil { user.profile.photo } which is much cleaner than, say, - user && user.profile && user.profile.photo + user && user.profile && user.profile.photo and much much safer than - user.profile.photo rescue nil + user.profile.photo rescue nil which will eat any error, even if it's one you really want to see. -== HELP! +== TELL ME MORE! + +The plugin is really rather simple; here's the ignore_nil method: + + def ignore_nil(&block) + begin + yield + rescue NoMethodError, RuntimeError => e + if (e.message =~ /You have a nil object when you didn't expect it/) || + (e.message =~ /undefined method `.*?' for nil:NilClass/) || (e.message =~ /^Called id for nil/) + return nil + else + raise e + end + end + end + +What's interesting about this is it catches both NoMethodError and RuntimeError, both of which +can occur if a method unexpectedly returned nil and you called a method on it, but *ONLY* if +the error message matches! This means legitimate NoMethodError and RuntimeError messages will +not be bothered by ignore_nil, and will still raise in your application as you expect. -I really think this is much better than the new try() syntax in Rails 2.3. -If you use and like this gem, please +1 it here: -https://rails.lighthouseapp.com/projects/8994/tickets/2364-ignore_nil-as-a-better-alternative-to-try +I've used this in a production application since about mid/late 2008, I'd consider it very stable. +Feedback welcome! == AUTHOR Steven Soroka -http://www.twitter.com/ssoroka -http://blog.stevensoroka.ca \ No newline at end of file +[@ssoroka](http://www.twitter.com/ssoroka) +[http://blog.stevensoroka.ca](http://blog.stevensoroka.ca) \ No newline at end of file README.rdoc @@ -2,7 +2,7 @@ require 'rubygems' require 'rake' require 'echoe' -Echoe.new('ignore_nil', '1.0.1') do |p| +Echoe.new('ignore_nil', '1.0.2') do |p| p.description = 'ignore_nil lets you happily ignore nil methods on long method chains. Keeps code pretty and much safer than "rescue nil", since it only catches NoMethodError on nil objects' p.url = 'http://github.com/ssoroka/ignore_nil' p.author = 'Steven Soroka' Rakefile @@ -1,28 +1,29 @@ +# -*- encoding: utf-8 -*- + Gem::Specification.new do |s| s.name = %q{ignore_nil} - s.version = "1.0.1" + s.version = "1.0.2" s.required_rubygems_version = Gem::Requirement.new(">= 1.2") if s.respond_to? :required_rubygems_version= s.authors = ["Steven Soroka"] - s.date = %q{2008-12-11} + s.date = %q{2009-09-23} s.description = %q{ignore_nil lets you happily ignore nil methods on long method chains. Keeps code pretty and much safer than "rescue nil", since it only catches NoMethodError on nil objects} s.email = %q{ssoroka78@gmail.com} s.extra_rdoc_files = ["lib/ignore_nil.rb", "README.rdoc"] s.files = ["ignore_nil.gemspec", "init.rb", "lib/ignore_nil.rb", "Manifest", "Rakefile", "README.rdoc", "test/ignore_nil_test.rb"] - s.has_rdoc = true s.homepage = %q{http://github.com/ssoroka/ignore_nil} s.rdoc_options = ["--line-numbers", "--inline-source", "--title", "Ignore_nil", "--main", "README.rdoc"] s.require_paths = ["lib"] s.rubyforge_project = %q{ignore_nil} - s.rubygems_version = %q{1.2.0} + s.rubygems_version = %q{1.3.3} s.summary = %q{ignore_nil lets you happily ignore nil methods on long method chains. Keeps code pretty and much safer than "rescue nil", since it only catches NoMethodError on nil objects} s.test_files = ["test/ignore_nil_test.rb"] if s.respond_to? :specification_version then current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION - s.specification_version = 2 + s.specification_version = 3 - if current_version >= 3 then + if Gem::Version.new(Gem::RubyGemsVersion) >= Gem::Version.new('1.2.0') then else end else ignore_nil.gemspec @@ -1 +1 @@ -require File.join(File.dirname(__FILE__),'lib','ignore_nil.rb') \ No newline at end of file +require File.join(File.dirname(__FILE__), 'lib', 'ignore_nil') \ No newline at end of file init.rb dcc2936c1eac8e027554a2e2f24ce1cbd7f66c12 Steven Soroka ssoroka78@gmail.com http://github.com/ssoroka/ignore_nil/commit/514620f957f95aaa83590a07ae1244ace15b68ae 514620f957f95aaa83590a07ae1244ace15b68ae 2009-09-22T23:42:16-07:00 2009-09-22T23:42:16-07:00 update README with some more details. bump to 1.0.2 just for the heck of it. dbbe1fe1dc2f628c59c196b5cfec546806d2e247 Steven Soroka ssoroka78@gmail.com