feat(ios): expose api to use sf images

apidoc/Titanium/UI/iOS/iOS.yml

@@ -40,6 +40,21 @@ methods:
     since: "5.2.0"
     osver: {ios: {min: "9.1"}}
 
+  - name: systemImage
+    summary: |
+        Get image from SF Symbol provided by Apple.
+    description: |
+        More details on SF Symbols can be found from https://developer.apple.com/design/human-interface-guidelines/sf-symbols/overview.
+        One can download SF Symbols app from https://developer.apple.com/design/downloads/SF-Symbols.dmg and 
+        can get the inbuilt SF Symbol name.
+    parameters:
+      - name: name
+        summary: Name of SF Symbol.
+        type: String
+    returns:
+      - type: Titanium.Blob
+    since: "8.2.0"
+    osver: {ios: {min: "13.0"}}
 properties:
   - name: LARGE_TITLE_DISPLAY_MODE_AUTOMATIC
     summary: |

iphone/Classes/TiUIiOSProxy.m

@@ -388,6 +388,19 @@ - (TiUIiOSSystemIconProxy *)SystemIcon
 }
 #endif
 
+#ifdef IS_SDK_IOS_13
+- (TiBlob *)systemImage:(id)arg
+{
+  if (![TiUtils isIOSVersionOrGreater:@"13.0"]) {
+    return nil;
+  }
+  ENSURE_SINGLE_ARG_OR_NIL(arg, NSString);
+  UIImage *image = [UIImage systemImageNamed:arg];
+  TiBlob *blob = [[TiBlob alloc] initWithImage:image];
+  return blob;
+}
+#endif
+
 - (void)setAppBadge:(id)value
 {
   ENSURE_UI_THREAD(setAppBadge, value);

iphone/TitaniumKit/TitaniumKit/Sources/API/TiUIView.m

@@ -10,6 +10,7 @@
 #import "Ti3DMatrix.h"
 #import "TiApp.h"
 #import "TiBase.h"
+#import "TiBlob.h"
 #import "TiColor.h"
 #import "TiRect.h"
 #import "TiUtils.h"
@@ -312,7 +313,7 @@ - (UIImage *)loadImage:(id)image
   if (image == nil)
     return nil;
   NSURL *url = [TiUtils toURL:image proxy:proxy];
-  if (url == nil) {
+  if (url == nil && ![image isKindOfClass:[TiBlob class]]) {
     NSLog(@"[WARN] could not find image: %@", image);
     return nil;
   }