fix: Fix value binding issue in the editor

Author: jaywcjlove

Example/Example/ContentView.swift

@@ -50,7 +50,7 @@ struct ContentView: View {
     }
     var body: some View {
         VStack(spacing: 0) {
-            TextField("Placeholder", text: $textForTextField)
+//            TextField("Placeholder", text: $textForTextField)
 //            ScrollView {
 //                Text(value)
 //            }

Example/Example/ExampleApp.swift

@@ -6,6 +6,7 @@
 //
 
 import SwiftUI
+import CodeMirror
 
 @main
 struct ExampleApp: App {
@@ -15,3 +16,12 @@ struct ExampleApp: App {
         }
     }
 }
+
+struct ContentView2: View {
+    @State var value: String = ""
+    var body: some View {
+        CodeMirror(value: $value, prompt: String(localized: "Please enter text"))
+            .cmLanguage(.constant(.html))
+            .cmLineWrapping(.constant(true))
+    }
+}

Sources/CodeMirror/CodeMirrorView.swift

@@ -16,14 +16,14 @@ import WebKit
 public struct CodeMirrorView: NativeView {
     @ObservedObject public var vm: CodeMirrorVM
     @Binding var value: String
-    @State var previewValue: String = ""
+    var prevValue: String = ""
     public init(
         _ viewModel: CodeMirrorVM,
         value: Binding<String>
     ) {
         self.vm = viewModel
         self._value = value
-        self.previewValue = value.wrappedValue
+        self.prevValue = value.wrappedValue
     }
 #if canImport(AppKit)
     public func makeNSView(context: Context) -> WKWebView {
@@ -125,7 +125,7 @@ public struct CodeMirrorView: NativeView {
                 args: [:]
             )
         )
-        if previewValue != value {
+        if prevValue != value {
             context.coordinator.queueJavascriptFunction(
                 JavascriptFunction(
                     functionString: "CodeMirror.setContent(value)",
@@ -220,10 +220,9 @@ extension Coordinator: WKScriptMessageHandler {
             callPendingFunctions()
         case ScriptMessageName.codeMirrorContentDidChange:
             parent.vm.onContentChange?()
-            Task {
-                guard let content = try await parent.vm.getContent() else { return }
-                parent.value = content
-                parent.previewValue = content
+            if let messageBody = message.body as? String {
+                parent.value = messageBody
+                parent.prevValue = messageBody
             }
         default:
             print("CodeMirrorWebView receive \(message.name) \(message.body)")

Sources/CodeMirror/web.bundle/codemirror.bundle.js

@@ -17,9 +17,8 @@
       if (window.webkit) {
         window.webkit.messageHandlers.codeMirrorDidReady.postMessage(null);
         CodeMirror.setListener(() => {
-          window.webkit.messageHandlers.codeMirrorContentDidChange.postMessage(
-            null
-          );
+            let code = CodeMirror.getContent();
+            window.webkit.messageHandlers.codeMirrorContentDidChange.postMessage(code);
         });
       }
     </script>

Sources/CodeMirror/web.bundle/index.html

@@ -218,7 +218,8 @@ const editorView = new CodeMirror.EditorView({
     lineNumber.of([]),
     baseTheme,
     theme.of(oneDark),
-    language.of(json()),
+    language.of(),
+    // language.of(json()),
     listener.of([]),
   ],
   parent: document.body,