Added iOS implementation for applyInstantJson and exportInstantJson. Added the apply instant Json example to iOS.

Author: aksh1t

example/lib/main.dart

@@ -299,6 +299,17 @@ class _MyAppState extends State<MyApp> {
                 Text(_formExampleSub, style: subhead)
               ])),
         ),
+        Divider(),
+        GestureDetector(
+          onTap: importInstantJsonExample,
+          child: Container(
+              padding: padding,
+              child: Column(crossAxisAlignment: crossAxisAlignment, children: [
+
+                Text(_importInstantJsonExample, style: title),
+                Text(_importInstantJsonExampleSub, style: subhead)
+              ])),
+        ),
         Divider()
       ];
       return CupertinoApp(

ios/Classes/PspdfkitPlugin.m

@@ -37,6 +37,39 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     } else if ([@"getFormFieldValue" isEqualToString:call.method]) {
         NSString *fullyQualifiedName = call.arguments[@"fullyQualifiedName"];
         result([self getFormFieldValueForFieldWithFullyQualifiedName:fullyQualifiedName]);
+    } else if ([@"applyInstantJson" isEqualToString:call.method]) {
+        NSString *annotationsJson = call.arguments[@"annotationsJson"];
+        if (annotationsJson == nil || annotationsJson.length <= 0) {
+            result([FlutterError errorWithCode:@"" message:@"annotationsJson may not be nil or empty." details:nil]);
+            return;
+        }
+        PSPDFDocument *document = self.pdfViewController.document;
+        if (!document || !document.isValid) {
+            result([FlutterError errorWithCode:@"" message:@"PDF document not found or is invalid." details:nil]);
+            return;
+        }
+        PSPDFDataContainerProvider *jsonContainer = [[PSPDFDataContainerProvider alloc] initWithData:[annotationsJson dataUsingEncoding:NSUTF8StringEncoding]];
+        NSError *error;
+        BOOL success = [document applyInstantJSONFromDataProvider:jsonContainer toDocumentProvider:document.documentProviders.firstObject lenient:NO error:&error];
+        if (!success) {
+            result([FlutterError errorWithCode:@"" message:@"Error while importing document Instant JSON." details:nil]);
+        } else {
+            result(@(YES));
+        }
+    } else if ([@"exportInstantJson" isEqualToString:call.method]) {
+        PSPDFDocument *document = self.pdfViewController.document;
+        if (!document || !document.isValid) {
+            result([FlutterError errorWithCode:@"" message:@"PDF document not found or is invalid." details:nil]);
+            return;
+        }
+        NSError *error;
+        NSData *data = [document generateInstantJSONFromDocumentProvider:document.documentProviders.firstObject error:&error];
+        NSString *annotationsJson = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
+        if (annotationsJson == nil || annotationsJson.length <= 0 || error) {
+            result([FlutterError errorWithCode:@"" message:@"Error while exporting document Instant JSON." details:nil]);
+        } else {
+            result(annotationsJson);
+        }
     } else if ([@"present" isEqualToString:call.method]) {
         NSString *documentPath = call.arguments[@"document"];