Rename observe/unobserve to add_observer/remove_observer

opal · Sep 13, 2013 · 7ca95e1 · 7ca95e1
1 parent ea44b59
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Showing 3 changed files with 41 additions and 14 deletions.
diff --git a/README.md b/README.md
@@ -218,6 +218,33 @@ end
 # => need to show user: 5
 ```
 
+## Observable
+
+Adds KVO style attribute observing.
+
+```ruby
+class MyObject
+  include Vienna::Observable
+
+  attr_accessor :name
+  attr_reader :age
+
+  def age=(age)
+    @age = age + 10
+  end
+end
+
+obj = MyObject.new
+obj.add_observer(:name) { |new_val| puts "name changed to #{new_val}" }
+obj.add_observer(:age) { |new_age| puts "age changed to #{new_age}" }
+
+obj.name = "bob"
+obj.age = 42
+
+# => "name changed to bob"
+# => "age changed to 52"
+```
+
 #### Todo
 
 * Support older browsers which do not support onhashchange.

diff --git a/opal/vienna/observable.rb b/opal/vienna/observable.rb
@@ -1,7 +1,7 @@
 module Vienna
   module Observable
 
-    def observe(attribute, &handler)
+    def add_observer(attribute, &handler)
       unless observers = @attr_observers
         observers = @attr_observers = {}
         old_values = @attr_old_values = {}
@@ -15,7 +15,7 @@ def observe(attribute, &handler)
       handlers << handler
     end
 
-    def unobserve(attribute, handler)
+    def remove_observer(attribute, handler)
       return unless @attr_observers
 
       if handlers = @attr_observers[attribute]

diff --git a/spec/observable_spec.rb b/spec/observable_spec.rb
@@ -47,10 +47,10 @@ def object.attribute_did_change(attribute); @_called = attribute; end
     end
   end
 
-  describe "#observe" do
+  describe "#add_observer" do
     it "handlers can be added to observe specific attributes" do
       count = 0
-      object.observe(:foo) { count += 1 }
+      object.add_observer(:foo) { count += 1 }
 
       object.foo = 100
       count.should eq(1)
@@ -61,8 +61,8 @@ def object.attribute_did_change(attribute); @_called = attribute; end
 
     it "allows more than one handler to be added for an attribute" do
       result = []
-      object.observe(:foo) { result << :first }
-      object.observe(:foo) { result << :second }
+      object.add_observer(:foo) { result << :first }
+      object.add_observer(:foo) { result << :second }
 
       object.foo = 42
       result.should eq([:first, :second])
@@ -78,13 +78,13 @@ def object.attribute_did_change(attribute); @_called = attribute; end
     end
 
     it "does not break when given an attriubte with no observers (but another observable exists)" do
-      object.observe(:foo) {}
+      object.add_observer(:foo) {}
       object.attribute_did_change(:bar)
     end
 
     it "passes new value to each handler" do
       result = nil
-      object.observe(:foo) { |val| result = val }
+      object.add_observer(:foo) { |val| result = val }
 
       object.foo = 42
       result.should eq(42)
@@ -94,26 +94,26 @@ def object.attribute_did_change(attribute); @_called = attribute; end
     end
   end
 
-  describe "#unobserve" do
+  describe "#remove_observer" do
     it "has no effect when no observers setup for attribute" do
-      object.unobserve(:foo, proc {})
+      object.remove_observer(:foo, proc {})
     end
 
     it "has no effect if the handler doesnt exist for attribute" do
       p = proc {}
-      object.observe(:foo) {}
-      object.unobserve(:foo, p)
+      object.add_observer(:foo) {}
+      object.remove_observer(:foo, p)
     end
 
     it "removes an existing handler for given attribute" do
       count = 0
       handler = proc { count += 1 }
-      object.observe(:foo, &handler)
+      object.add_observer(:foo, &handler)
 
       object.foo = 42
       count.should eq(1)
 
-      object.unobserve(:foo, handler)
+      object.remove_observer(:foo, handler)
       object.foo = 49
       count.should eq(1)
     end