Implement nativeID prop to allow native code to reference react managed views in iOS

Reviewed By: javache

Differential Revision: D5228055

fbshipit-source-id: 8c934501d4ac946d80bf93d2ddb50f5fc38aea3c

Libraries/Components/View/ViewPropTypes.js

@@ -218,8 +218,6 @@ module.exports = {
    * Used to locate this view from native classes.
    *
    * > This disables the 'layout-only view removal' optimization for this view!
-   *
-   * @platform android
    */
   nativeID: PropTypes.string,
 

Libraries/Text/Text.js

@@ -179,7 +179,6 @@ const Text = React.createClass({
     testID: PropTypes.string,
     /**
      * Used to locate this view from native code.
-     * @platform android
      */
     nativeID: PropTypes.string,
     /**

React/Modules/RCTUIManager.h

@@ -147,6 +147,16 @@ RCT_EXTERN NSString *const RCTUIManagerRootViewKey;
  */
 - (void)rootViewForReactTag:(NSNumber *)reactTag withCompletion:(void (^)(UIView *view))completion;
 
+/**
+ * Finds a view that is tagged with {@param nativeId} as its nativeID prop
+ * with the associated {@param rootTag} root tag view hierarchy. Returns the
+ * view if found, nil otherwise.
+ *
+ * @param nativeID the id reference to native component relative to root view.
+ * @param rootTag the react tag of root view hierarchy from which to find the view.
+ */
+- (UIView *)viewForNativeID:(NSString *)nativeID withRootTag:(NSNumber *)rootTag;
+
 /**
  * The view that is currently first responder, according to the JS context.
  */

React/Modules/RCTUIManager.m

@@ -433,6 +433,33 @@ BOOL RCTIsUIManagerQueue()
   });
 }
 
+/**
+ * TODO(yuwang): implement the nativeID functionality in a more efficient way
+ *               instead of searching the whole view tree
+ */
+- (UIView *)viewForNativeID:(NSString *)nativeID withRootTag:(NSNumber *)rootTag
+{
+  RCTAssertMainQueue();
+  UIView *view = [self viewForReactTag:rootTag];
+  return [self _lookupViewForNativeID:nativeID inView:view];
+}
+
+- (UIView *)_lookupViewForNativeID:(NSString *)nativeID inView:(UIView *)view
+{
+  RCTAssertMainQueue();
+  if (view != nil && [nativeID isEqualToString:view.nativeID]) {
+    return view;
+  }
+
+  for (UIView *subview in view.subviews) {
+    UIView *targetView = [self _lookupViewForNativeID:nativeID inView:subview];
+    if (targetView != nil) {
+      return targetView;
+    }
+  }
+  return nil;
+}
+
 - (void)setSize:(CGSize)size forView:(UIView *)view
 {
   RCTAssertMainQueue();

React/Views/RCTViewManager.m

@@ -114,6 +114,8 @@ RCT_EXPORT_VIEW_PROPERTY(hasTVPreferredFocus, BOOL)
 RCT_EXPORT_VIEW_PROPERTY(tvParallaxProperties, NSDictionary)
 #endif
 
+RCT_EXPORT_VIEW_PROPERTY(nativeID, NSString)
+
 // Acessibility related properties
 RCT_REMAP_VIEW_PROPERTY(accessible, reactAccessibilityElement.isAccessibilityElement, BOOL)
 RCT_REMAP_VIEW_PROPERTY(accessibilityLabel, reactAccessibilityElement.accessibilityLabel, NSString)

React/Views/UIView+React.h

@@ -24,6 +24,11 @@
 - (void)insertReactSubview:(UIView *)subview atIndex:(NSInteger)atIndex NS_REQUIRES_SUPER;
 - (void)removeReactSubview:(UIView *)subview NS_REQUIRES_SUPER;
 
+/**
+ * The native id of the view, used to locate view from native codes
+ */
+@property (nonatomic, copy) NSString *nativeID;
+
 /**
  * Layout direction of the view.
  * Internally backed to `semanticContentAttribute` property.

React/Views/UIView+React.m

@@ -27,6 +27,16 @@
   objc_setAssociatedObject(self, @selector(reactTag), reactTag, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }
 
+- (NSNumber *)nativeID
+{
+  return objc_getAssociatedObject(self, _cmd);
+}
+
+- (void)setNativeID:(NSNumber *)nativeID
+{
+  objc_setAssociatedObject(self, @selector(nativeID), nativeID, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
 #if RCT_DEV
 
 - (RCTShadowView *)_DEBUG_reactShadowView