Validate with conditions

.travis.yml

@@ -2,6 +2,9 @@ language: objective-c
 before_install:
   - ruby --version
   - sudo chown -R travis ~/Library/RubyMotion
-rvm:
-  - "1.9.3"
-script: bundle exec rake spec
+  - mkdir -p ~/Library/RubyMotion/build
+  - sudo motion update
+gemfile:
+  - Gemfile
+script:
+  - bundle exec rake spec

Gemfile

@@ -1,5 +1,5 @@
 source "https://rubygems.org"
 
 gem "rake"
-gem "bubble-wrap"
 gem "motion-stump", '~>0.2'
+gemspec

Gemfile.lock

@@ -1,14 +1,26 @@
+PATH
+  remote: .
+  specs:
+    motion_model (0.6.0)
+      bubble-wrap (>= 1.3.0)
+      motion-support (>= 0.1.0)
+
 GEM
   remote: https://rubygems.org/
   specs:
-    bubble-wrap (1.4.0)
+    bubble-wrap (1.7.1)
+      bubble-wrap-http (= 1.7.1)
+    bubble-wrap-http (1.7.1)
+    motion-require (0.2.0)
     motion-stump (0.3.0)
-    rake (10.1.0)
+    motion-support (0.2.6)
+      motion-require (>= 0.0.6)
+    rake (10.3.2)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  bubble-wrap
   motion-stump (~> 0.2)
+  motion_model!
   rake

README.md

@@ -362,6 +362,19 @@ Here are some sample validations:
     validate :field_name, :email => true
     validate :field_name, :format => /\A\d?\d-\d?\d-\d\d\Z/ # expected string format would be like '12-12-12'
 
+You can also define conditions to execute validations just in some contexts:
+```ruby
+# using a method passed as symbol
+validate :field_name, :presence => true, :if => :some_context?
+
+# or directly with proc/lambda
+validate :filed_name, :presence => true, :if => -> { # stuff here }
+
+def some_context?
+  # Your conditional stuff here
+end
+```
+
 The framework is sufficiently flexible that you can add in custom validators like so:
 
 ```ruby

motion/validatable.rb

@@ -130,7 +130,22 @@ def validate_for(field, value)
       result
     end
 
+    def must_validate?(validation)
+      stuff = validation[:if]
+      return true unless stuff
+
+      case stuff
+      when Symbol then send(stuff)
+      when Proc then instance_exec(&stuff)
+      else
+        fail ArgumentError,
+             ':if requires a Symbol denoting a method or a Proc/lambda'
+      end
+    end
+
     def validate_one(field, validation) #nodoc
+      return true unless must_validate?(validation)
+
       result = true
       validation.each_pair do |validation_type, setting|
         if self.respond_to? validation_method(validation_type)

spec/validation_spec.rb

@@ -6,7 +6,9 @@ class ValidatableTask
                 :email => :string,
                 :some_day => :string,
                 :some_float => :float,
-                :some_int => :int
+                :some_int => :int,
+                :if_with_proc => :string,
+                :if_with_sym => :string
 
   validate      :name, :presence => true
   validate      :name, :length => 2..10
@@ -15,6 +17,12 @@ class ValidatableTask
   validate      :some_day, :length => 8..10
   validate      :some_float, :presence => true
   validate      :some_int, :presence => true
+  validate      :if_with_proc, :presence => true, :if => -> { if_with_proc == 'unexpected' }
+  validate      :if_with_sym, :presence => true, :if => :false_condition_method
+
+  def false_condition_method
+    false
+  end
 end
 
 describe "validations" do
@@ -24,10 +32,28 @@ class ValidatableTask
       :email => 'bob@domain.com',
       :some_day => '12-12-12',
       :some_float => 1.080,
-      :some_int => 99
+      :some_int => 99,
+      :if_with_proc => 'Never validated column',
+      :if_with_sym => 'Never validated column'
     }
   end
 
+  describe 'conditional validation' do
+    context 'with conditional by method' do
+      it 'does not validate if condition returns false' do
+        task = ValidatableTask.new(@valid_tasks.except(:if_with_sym))
+        task.valid?.should == true
+      end
+    end
+
+    context 'with conditional by proc' do
+      it 'does not validate if condition returns false' do
+        task = ValidatableTask.new(@valid_tasks.except(:if_with_proc))
+        task.valid?.should == true
+      end
+    end
+  end
+
   describe "presence" do
     it "is initially false if name is blank" do
       task = ValidatableTask.new(@valid_tasks.except(:name))