@@ -1,4 +1,4 @@ -Copyright (c) 2008 Michel Martens for CitrusByte (http://www.citrusbyte.com) +Copyright (c) 2008 Michel Martens and Damian Janowski Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the LICENSE @@ -52,12 +52,22 @@ Or, if you need something special: @user = User.spawn :name => "Michel Martens" -### Using the attributes hash inside the block +Conditional evaluation +---------------------- -Some times the RHS of your assignment is costly or has side effects, -and you don't want it to execute when you already passed the value -in the attributes hash. Since the values are passed to the block, -you can benefit from using `||=`: +Spawn will execute the right hand side of your assignment even if you +provide a value for some particular key. Consider the following example: + + User.spawner do |user| + user.profile = Profile.spawn # Profile.spawn is executed even if you provide a value for :profile. + end + + User.spawn(:profile => Profile.first) + +Here, you will be creating an extra instance of `Profile`, because when +the block is evaluated it calls `Profile.spawn`. If the right hand side +of your assignment is costly or has side effects, you may want to avoid +this behavior by using `||=`: User.spawner do |user| user.profile ||= Profile.spawn @@ -67,7 +77,7 @@ Then, if you pass a `:profile`: User.spawn(:profile => Profile.first) -You can verify that only once `Profile` was created. Although this +You can verify that `Profile.spawn` is never called. Although this may sound evident, it can bite you if you rely on the RHS not executing (e.g. if you're using Spawn to populate fake data into a database and you want to control how many instances you create). @@ -85,7 +95,7 @@ Thanks to [Foca](http://github.com/foca) for his suggestions and License ------- -Copyright (c) 2009 Michel Martens for Citrusbyte +Copyright (c) 2009 Michel Martens and Damian Janowski Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation README.markdown @@ -3,8 +3,8 @@ Gem::Specification.new do |s| s.version = '0.1.1' s.summary = %{Simple fixtures replacement for Sequel, ActiveRecord, Ohm and probably many other ORMs} s.description = %{Spawn is a very small library (just 14 lines of code) that can effectively replace fixtures or any other library for the same task.} - s.email = "michel@soveran.com" - s.author = "Michel Martens" + s.authors = ["Michel Martens", "Damian Janowski"] + s.email = ["michel@soveran.com", "djanowski@dimaion.com"] s.homepage = "http://github.com/soveran/spawn" s.files = <%= Dir['lib/**/*.rb', 'rails/**/*.rb', 'README*', 'LICENSE', 'Rakefile', 'test/**/*.*', '*.gemspec'].inspect %> s.require_paths = ['lib'] spawn.gemspec.erb fc85130847d6aff69c97e5b2efcf173875053821 Michel Martens michel@soveran.com http://github.com/soveran/spawn/commit/812a766ed11c4028f9dab65d0028215a1156ffd1 812a766ed11c4028f9dab65d0028215a1156ffd1 2009-06-12T10:34:04-07:00 2009-06-12T10:34:04-07:00 Updated README and gemspec 6d5ceabf6d3ef0c437862c1c1c6e5d9465d37b04 Michel Martens michel@soveran.com