Update README.md

Author: mfeingold

README.md

@@ -75,17 +75,18 @@ The value is relative to the visible height of the area, the default is 0.5 and
 * **start-index - value**, optional - index of the first item to be requested from the datasource. The default is 1.
 * **adapter - name**, optional - if provided a reference to the adapter object for the scroller instance will be placed in the member with the said name on the scope associated with the viewport. If the viewport is the window, the value will be placed on the $rootScope. If you have multiple scrollers within the same viewport, make sure that every one of them has its unique adapter name.
 
-* **adapter - expression**, optional - if provided a reference to the adapter object for the scroller instance will be injected in the specified scope. If you have multiple scrollers within the same viewport, make sure that every one of them has its unique adapter name.
-
-The expression can be any angular assignable expression. The scroller will try to treat the first part of the expression (the part to the left of the first `.`) as the name of the controller. If there is an (indirect) parent scope associated s of the scroller 
-The scope to inject the reference is the scope associated with the element marked with the [uiScrollViewport](#uiscrollviewport-directive) directive. If the viewport is the window, the value will be injected in the $rootScope. 
+* **adapter - expression**, optional - if provided a reference to the adapter object for the scroller instance will be injected in the appropriate scope. If you have multiple scrollers within the same viewport, make sure that every one of them has its unique adapter name.
 
 Some of the properties offered by the adapter can also be accessed directly from the directive by using matching attributes. In the same way as for the adapter attribute, syntax for such attributes allows for providing a name to be used to access the corresponding value. A reference to the value will be placed on the scope associated with the viewport. If the viewport is the window, the value will be placed on the $rootScope.  Below is a list of such attributes:
 
-* **is-loading - name**, optional - a boolean value indicating whether there are any pending load requests will be placed in the member with the said name. See also `isLoading` adapter property.
-* **top-visible - name**, optional - a reference to the item currently in the topmost visible position will be placed in the member with the said name. See also `topVisible` adapter property.
-* **top-visible-element - name**, optional - a reference to the DOM element currently in the topmost visible position will be placed in the member with the said name. See also `topVisibleElement` adapter property.
-* **top-visible-scope - name**, optional - a reference to the scope created for the item currently in the topmost visible position will be placed in the member with the said name. See also `topVisibleScope` adapter property.
+* **is-loading - expression**, optional - a boolean value indicating whether there are any pending load requests will be injected in the appropriate scope. See also `isLoading` adapter property.
+* **top-visible - expression**, optional - a reference to the item currently in the topmost visible position will be injected in the appropriate scope. See also `topVisible` adapter property.
+* **top-visible-element - expression**, optional - a reference to the DOM element currently in the topmost visible position will be injected in the appropriate scope. See also `topVisibleElement` adapter property.
+* **top-visible-scope - expression**, optional - a reference to the scope created for the item currently in the topmost visible position will be injected in the appropriate scope. See also `topVisibleScope` adapter property.
+
+The `expression` can be any angular assignable expression. The scroller will inject the requested value into the target scope by applying the target expression. The scope associated with the viewport (the element marked with the [uiScrollViewport](#uiscrollviewport-directive) directive) will be used as the target scope. If the viewport is not defined (window viewport), the $rootScope will be used as the target scope.
+
+The second format `expression on controller` can be used to explicitly specify the scope associated with the specified controller as the target scope for the injection. In this format `expression` is any angular assignable expression, and `controller` is the name of controller constructor function as specified in the `ng-controller` directive. The scroller will traverse its parents to locate the target scope associated with the specified controller.
 
 ###Data Source
 Data source is an object to be used by the uiScroll directive to access the data.