From 265aefb5ac393931f967983a0bd85922c950eb79 Mon Sep 17 00:00:00 2001
From: MetalMallard <alexandre_46@live.fr>
Date: Fri, 26 Nov 2021 13:58:21 +0100
Subject: [PATCH] Adding signTypedDataV4 method to interop.js and equivalent
 method to MetaMaskService.cs

---
 MetaMask.Blazor/MetaMaskService.cs           | 14 +++++++++++++
 MetaMask.Blazor/wwwroot/metaMaskJsInterop.js | 21 ++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/MetaMask.Blazor/MetaMaskService.cs b/MetaMask.Blazor/MetaMaskService.cs
index ecec1c5..c04f16a 100644
--- a/MetaMask.Blazor/MetaMaskService.cs
+++ b/MetaMask.Blazor/MetaMaskService.cs
@@ -162,6 +162,20 @@ public async ValueTask<string> SignTypedData(string label, string value)
                 throw;
             }
         }
+        
+        public async ValueTask<string> SignTypedDataV4(string typedData)
+        {
+            var module = await moduleTask.Value;
+            try
+            {
+                return await module.InvokeAsync<string>("signTypedDataV4", typedData);
+            }
+            catch (Exception ex)
+            {
+                HandleExceptions(ex);
+                throw;
+            }
+        }
 
         public async ValueTask<string> SendTransaction(string to, BigInteger weiValue, string? data = null)
         {
diff --git a/MetaMask.Blazor/wwwroot/metaMaskJsInterop.js b/MetaMask.Blazor/wwwroot/metaMaskJsInterop.js
index 5f8f504..90bbd65 100644
--- a/MetaMask.Blazor/wwwroot/metaMaskJsInterop.js
+++ b/MetaMask.Blazor/wwwroot/metaMaskJsInterop.js
@@ -117,6 +117,27 @@ export async function signTypedData(label, value) {
     }
 }
 
+export async function signTypedDataV4(typedData) {
+    await checkMetaMask();
+    
+    try {
+        var result = await ethereum.request({
+            method: 'eth_signTypedData_v4',
+            params:
+                [
+                    ethereum.selectedAddress,
+                    typedData
+                ],
+            from: ethereum.selectedAddress
+        });
+
+        return result;
+    } catch (error) {
+        // User denied account access...
+        throw "UserDenied"
+    }
+}
+
 export async function sendTransaction(to, value, data) {
     await checkMetaMask();