Adds Clash to the mix.

4 files changed, 158 insertions, 9 deletions

diff --git a/README.rdoc b/README.rdoc
index 2fdf033..a8b8d10 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -4,14 +4,8 @@ Hashie is a growing collection of tools that extend Hashes and make
 them more useful.
 
 == Installation
-
-Hashie is a gem and is available on Gemcutter. If you don't have Gemcutter,
-install it:
-
-    gem install gemcutter
-    gem tumble
     
-Then you can install Hashie:
+Hashie is available as a RubyGem:
 
     gem install hashie
 
@@ -62,7 +56,33 @@ can set defaults for each property.
     p = Person.new(:name => "Bob")
     p.name       # => 'Bob'
     p.occupation # => 'Rubyist'
-  
+    
+== Clash
+
+Clash is a Chainable Lazy Hash that allows you to easily construct
+complex hashes using method notation chaining. This will allow you
+to use a more action-oriented approach to building options hashes.
+
+Essentially, a Clash is a generalized way to provide much of the same
+kind of "chainability" that libraries like Arel or Rails 2.x's named_scopes
+provide.
+
+=== Example
+
+    c = Hashie::Clash.new
+    c.where(:abc => 'def').order(:created_at)
+    c # => {:where => {:abc => 'def}, :order => :created_at}
+
+    # You can also use bang notation to chain into sub-hashes,
+    # jumping back up the chain with _end!
+    c = Hashie::Clash.new
+    c.where!.abc('def').ghi(123)._end!.order(:created_at)
+    c # => {:where => {:abc => 'def', :ghi => 123}, :order => :created_at}
+
+    # Multiple hashes are merged automatically
+    c = Hashie::Clash.new
+    c.where(:abc => 'def').where(:hgi => 123)
+    c # => {:where => {:abc => 'def', :hgi => 123}}
 
 == Note on Patches/Pull Requests
  
diff --git a/lib/hashie.rb b/lib/hashie.rb
index 87c8d45..06c238a 100644
--- a/lib/hashie.rb
+++ b/lib/hashie.rb
@@ -1,4 +1,5 @@
 require 'hashie/hash_extensions'
 require 'hashie/hash'
 require 'hashie/mash'
-require 'hashie/dash'
\ No newline at end of file
+require 'hashie/dash'
+require 'hashie/clash'
\ No newline at end of file
diff --git a/lib/hashie/clash.rb b/lib/hashie/clash.rb
new file mode 100644
index 0000000..8a8ed7b
--- /dev/null
+++ b/lib/hashie/clash.rb
@@ -0,0 +1,86 @@
+require 'hashie/hash'
+
+module Hashie
+  #
+  # A Clash is a "Chainable Lazy Hash". Inspired by libraries such as Arel,
+  # a Clash allows you to chain together method arguments to build a 
+  # hash, something that's especially useful if you're doing something
+  # like constructing a complex options hash. Here's a basic example:
+  # 
+  #     c = Hashie::Clash.new.conditions(:foo => 'bar').order(:created_at)
+  #     c # => {:conditions => {:foo => 'bar'}, :order => :created_at}
+  #
+  # Clash provides another way to create sub-hashes by using bang notation.
+  # You can dive into a sub-hash by providing a key with a bang and dive
+  # back out again with the _end! method. Example:
+  #
+  #     c = Hashie::Clash.new.conditions!.foo('bar').baz(123)._end!.order(:created_at)
+  #     c # => {:conditions => {:foo => 'bar', :baz => 123}, :order => :created_at}
+  #
+  # Because the primary functionality of Clash is to build options objects,
+  # all keys are converted to symbols since many libraries expect symbols explicitly
+  # for keys.
+  #
+  class Clash < ::Hash
+    class ChainError < ::StandardError; end
+    # The parent Clash if this Clash was created via chaining.
+    attr_reader :_parent
+    
+    # Initialize a new clash by passing in a Hash to
+    # convert and, optionally, the parent to which this
+    # Clash is chained.
+    def initialize(other_hash = {}, parent = nil)
+      @_parent = parent
+      other_hash.each_pair do |k, v|
+        self[k.to_sym] = v
+      end
+    end
+    
+    # Jump back up a level if you are using bang method
+    # chaining. For example:
+    #
+    # c = Hashie::Clash.new.foo('bar')
+    # c.baz!.foo(123) # => c[:baz]
+    # c.baz!._end! # => c
+    def _end!
+      self._parent
+    end
+    
+    def id(*args) #:nodoc:
+      method_missing(:id, *args)
+    end
+    
+    def merge_store(key, *args) #:nodoc:
+      case args.length
+        when 1
+          val = args.first
+          val = self[key].merge(val) if self[key].is_a?(::Hash) && val.is_a?(::Hash)
+        else
+          val = args
+      end
+
+      self[key.to_sym] = val
+      self
+    end
+    
+    def method_missing(name, *args) #:nodoc:
+      name = name.to_s
+      if name.match(/!$/) && args.empty?
+        key = name[0...-1].to_sym
+        
+        if self[key].nil?
+          self[key] = Clash.new({}, self)
+        elsif self[key].is_a?(::Hash) && !self[key].is_a?(Clash)
+          self[key] = Clash.new(self[key], self)
+        else
+          raise ChainError, "Tried to chain into a non-hash key."
+        end
+        
+        self[key]
+      elsif args.any?
+        key = name.to_sym
+        self.merge_store(key, *args)
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/hashie/clash_spec.rb b/spec/hashie/clash_spec.rb
new file mode 100644
index 0000000..6363d5d
--- /dev/null
+++ b/spec/hashie/clash_spec.rb
@@ -0,0 +1,42 @@
+require File.dirname(__FILE__) + '/../spec_helper'
+
+describe Hashie::Clash do
+  before do
+    @c = Hashie::Clash.new
+  end
+  
+  it 'should be able to set an attribute via method_missing' do
+    @c.foo('bar')
+    @c[:foo].should == 'bar'
+  end
+  
+  it 'should be able to set multiple attributes' do
+    @c.foo('bar').baz('wok')
+    @c.should == {:foo => 'bar', :baz => 'wok'}
+  end
+  
+  it 'should convert multiple arguments into an array' do
+    @c.foo(1, 2, 3)
+    @c[:foo].should == [1,2,3]
+  end
+  
+  it 'should be able to use bang notation to create a new Clash on a key' do
+    @c.foo!
+    @c[:foo].should be_kind_of(Hashie::Clash)
+  end
+  
+  it 'should be able to chain onto the new Clash when using bang notation' do
+    @c.foo!.bar('abc').baz(123)
+    @c.should == {:foo => {:bar => 'abc', :baz => 123}}
+  end
+  
+  it 'should be able to jump back up to the parent in the chain with #_end!' do
+    @c.foo!.bar('abc')._end!.baz(123)
+    @c.should == {:foo => {:bar => 'abc'}, :baz => 123}
+  end
+  
+  it 'should merge rather than replace existing keys' do
+    @c.where(:abc => 'def').where(:hgi => 123)
+    @c.should == {:where => {:abc => 'def', :hgi => 123}}
+  end
+end