lib/page_magic/watchers.rb in page_magic-2.0.0.alpha1 vs lib/page_magic/watchers.rb in page_magic-2.0.0

@@ -1,37 +1,39 @@
 # frozen_string_literal: true
 
-require 'page_magic/watcher'
+require_relative 'watcher'
 
 module PageMagic
   # module Watchers - contains methods for adding watchers and checking them
   module Watchers
     ELEMENT_MISSING_MSG = 'Unable to defined watcher: Element or method with the name %s can not be found'
 
     # @param [Symbol] name - the name of the watcher
     # @return [Boolean] true if a change is detected
     def changed?(name)
       watched_element = watcher(name)
-      watched_element.last != watched_element.check(self).last
+      watched_element.observed_value != watched_element.check.observed_value
     end
 
     # register a new watcher
-    # @param [Object] name of the watcher/element
-    # @param [Symbol] method - the method on the watched element to check
-    # @yieldreturn [Object] the value that should be checked
-    # @example
-    #  watch(:price, :text)
-    # @example
-    #  watch(:something) do
+    # @overload watch(:price, context: object, method: :text)
+    #  @param [Symbol] name of the watcher/element
+    #  @param [Object] context the object that is being watched - defaults to self
+    #  @param [Symbol] method - the method on the watched element to check
+    # @overload watch(:text)
+    #  @param [Symbol] method - the method on the watched element to check
+    # @overload watch(:text, &blk)
+    #  @param [Symbol] name of the watcher/element
+    #  @yieldreturn [Object] the value that should be checked
+    #  @example
+    #   watch(:something) do
     #   # more complicated code to get value
-    # end
-    def watch(name, method = nil, &block)
-      raise ElementMissingException, (ELEMENT_MISSING_MSG % name) unless block || respond_to?(name)
-
-      watched_element = block ? Watcher.new(name, &block) : Watcher.new(name, method)
+    #   end
+    def watch(name, context: self, method: nil, &blk)
+      watcher = blk ? Watcher.new(name, context: context, &blk) : watch_method(name, context: context, method: method)
       watchers.delete_if { |w| w.name == name }
-      watchers << watched_element.check(self)
+      watchers << watcher.check
     end
 
     # retrieve a watcher given its name
     # @param [Symbol] name the name of the watcher
     # @return [Watcher] watcher with the given name
@@ -40,8 +42,19 @@
     end
 
     # @return [Array] registered watchers
     def watchers
       @watchers ||= []
+    end
+
+    private
+
+    def watch_method(name, context:, method:)
+      subject = method || name
+      raise ElementMissingException, (ELEMENT_MISSING_MSG % subject) unless context.respond_to?(subject)
+
+      Watcher.new(name, context: context) do
+        public_send(subject)
+      end
     end
   end
 end