update attributes method

lib/couchrest/core/model.rb

@@ -247,7 +247,7 @@ module CouchRest
       #  
       # To understand the capabilities of this view system more compeletly,
       # it is recommended that you read the RSpec file at
-      # <tt>spec/core/model.rb</tt>.
+      # <tt>spec/core/model_spec.rb</tt>.
       def view_by *keys
         opts = keys.pop if keys.last.is_a?(Hash)
         opts ||= {}
@@ -386,6 +386,19 @@ module CouchRest
       self['_rev']
     end
 
+    # Takes a hash as argument, and applies the values by using writer methods
+    # for each key. Raises a NoMethodError if the corresponding methods are
+    # missing. In case of error, no attributes are changed.
+    def update_attributes hash
+      hash.each do |k, v|
+        raise NoMethodError, "#{k}= method not available, use key_accessor or key_writer :#{key}" unless self.respond_to?("#{k}=")
+      end      
+      hash.each do |k, v|
+        self.send("#{k}=",v)
+      end
+      save
+    end
+
     # returns true if the document has never been saved
     def new_record?
       !rev

spec/couchrest/core/model_spec.rb

@@ -133,6 +133,41 @@ describe CouchRest::Model do
     end
   end
   
+  describe "update attributes" do
+    before(:each) do
+      a = Article.get "big-bad-danger" rescue nil
+      a.destroy if a
+      @art = Article.new(:title => "big bad danger")
+      @art.save
+    end
+    it "should work for attribute= methods" do
+      @art['title'].should == "big bad danger"
+      @art.update_attributes('date' => Time.now, :title => "super danger")
+      @art['title'].should == "super danger"
+    end
+    
+    it "should flip out if an attribute= method is missing" do
+      lambda {
+        @art.update_attributes('slug' => "new-slug", :title => "super danger")        
+      }.should raise_error
+    end
+    
+    it "should not change other attributes if there is an error" do
+      lambda {
+        @art.update_attributes('slug' => "new-slug", :title => "super danger")        
+      }.should raise_error
+      @art['title'].should == "big bad danger"
+    end
+    
+    it "should save" do
+      @art['title'].should == "big bad danger"
+      @art.update_attributes('date' => Time.now, :title => "super danger")
+      loaded = Article.get @art.id
+      loaded['title'].should == "super danger"
+    end
+    
+  end
+  
   describe "a model with template values" do
     before(:all) do
       @tmpl = WithTemplate.new
@@ -326,7 +361,9 @@ describe CouchRest::Model do
   end
 
   describe "a model with timestamps" do
-    before(:all) do
+    before(:each) do
+      oldart = Article.get "saving-this" rescue nil
+      oldart.destroy if oldart
       @art = Article.new(:title => "Saving this")
       @art.save
     end