feat: add post methed for saml response (#1399)

web/src/common/CaptchaWidget.js

@@ -125,5 +125,5 @@ export const CaptchaWidget = ({captchaType, subType, siteKey, clientSecret, onCh
     }
   }, [captchaType, subType, siteKey, clientSecret, clientId2, clientSecret2]);
 
-  return <div id="captcha"></div>;
+  return <div id="captcha" />;
 };

web/src/common/RedirectForm.js

@@ -0,0 +1,43 @@
+// Copyright 2022 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import React, {useEffect} from "react";
+
+export const RedirectForm = (props) => {
+
+  useEffect(() => {
+    document.getElementById("saml").submit();
+  }, []);
+
+  return (<>
+    <p>Redirecting, please wait.</p>
+    <form id="saml" method="post" action={props.redirectUrl}>
+      <input
+        type="hidden"
+        name="SAMLResponse"
+        id="samlResponse"
+        value={props.samlResponse}
+      />
+      <input
+        type="hidden"
+        name="RelayState"
+        id="relayState"
+        value={props.relayState}
+      />
+    </form>
+  </>
+  );
+};
+
+export default RedirectForm;