default values and lambda unique_ids

lib/couchrest/core/model.rb

@@ -50,6 +50,11 @@ module CouchRest
     # instantiates the hash by converting all the keys to strings.
     def initialize keys = {}
       super()
+      if self.class.default
+        self.class.default.each do |k,v|
+          self[k.to_s] = v
+        end
+      end
       keys.each do |k,v|
         self[k.to_s] = v
       end
@@ -62,6 +67,7 @@ module CouchRest
       # this is the CouchRest::Database that model classes will use unless
       # they override it with <tt>use_database</tt>
       attr_accessor :default_database
+      attr_accessor :template
       
       # override the CouchRest::Model-wide default_database
        def use_database db
@@ -108,6 +114,14 @@ module CouchRest
          end
        end
        
+       def default
+         @default
+       end
+       
+       def set_default hash
+         @default = hash
+       end
+
        # Automatically set <tt>updated_at</tt> and <tt>created_at</tt> fields
        # on the document whenever saving occurs. CouchRest uses a pretty
        # decent time format by default. See Time#to_json
@@ -127,10 +141,18 @@ module CouchRest
        # must be globally unique across all document types which share a
        # database, so if you'd like to scope uniqueness to this class, you
        # should use the class name as part of the unique id.
-       def unique_id method
+       def unique_id method = nil, &block
+         if method
            define_method :set_unique_id do
              self['_id'] ||= self.send(method)
            end
+         elsif block
+           define_method :set_unique_id do
+             uniqid = block.call(self)
+             raise ArgumentError, "unique_id block must not return nil" if uniqid.nil?
+             self['_id'] ||= uniqid
+           end
+         end
        end
        
        # Define a CouchDB view. The name of the view will be the concatenation

spec/couchrest/core/model_spec.rb

@@ -1,7 +1,17 @@
 require File.dirname(__FILE__) + '/../../spec_helper'
 
 class Basic < CouchRest::Model
+end
 
+class WithTemplate < CouchRest::Model
+  unique_id do |model|
+    model['important-field']
+  end
+  set_default({
+    :preset => 'value',
+    'more-template' => [1,2,3]
+  })
+  key_accessor :preset
 end
 
 class Article < CouchRest::Model
@@ -105,6 +115,15 @@ describe CouchRest::Model do
     end
   end
   
+  describe "a model with template values" do
+    before(:all) do
+      @tmpl = WithTemplate.new
+    end
+    it "should have fields set when new" do
+      @tmpl.preset.should == 'value'
+    end
+  end
+  
   describe "getting a model" do
     before(:all) do
       @art = Article.new(:title => 'All About Getting')
@@ -184,6 +203,48 @@ describe CouchRest::Model do
     end
   end
 
+  describe "saving a model with a unique_id lambda" do
+    before(:each) do
+      @templated = WithTemplate.new
+      @old = WithTemplate.get('very-important') rescue nil
+      @old.destroy if @old
+    end
+    
+    it "should require the field" do
+      lambda{@templated.save}.should raise_error
+      @templated['important-field'] = 'very-important'
+      @templated.save.should == true
+    end
+    
+    it "should save with the id" do
+      @templated['important-field'] = 'very-important'
+      @templated.save.should == true
+      t = WithTemplate.get('very-important')
+      t.should == @templated
+    end
+    
+    it "should not change the id on update" do
+      @templated['important-field'] = 'very-important'
+      @templated.save.should == true
+      @templated['important-field'] = 'not-important'
+      @templated.save.should == true
+      t = WithTemplate.get('very-important')
+      t.should == @templated
+    end
+    
+    it "should raise an error when the id is taken" do
+      @templated['important-field'] = 'very-important'
+      @templated.save.should == true
+      lambda{WithTemplate.new('important-field' => 'very-important').save}.should raise_error
+    end
+    
+    it "should set the id" do
+      @templated['important-field'] = 'very-important'
+      @templated.save.should == true
+      @templated.id.should == 'very-important'
+    end
+  end
+
   describe "a model with timestamps" do
     before(:all) do
       @art = Article.new(:title => "Saving this")