Check if router is ready (#17)

pages/saml/login.tsx

@@ -6,6 +6,7 @@ import { useEffect, useRef, useState } from 'react';
 export default function Login() {
   const router = useRouter();
   const { id, audience, acsUrl, providerName, relayState } = router.query;
+  const isRouteReady = router.isReady;
 
   const [state, setState] = useState({
     username: 'jackson',
@@ -25,7 +26,7 @@ export default function Login() {
       acsUrlInp.current.focus();
       acsUrlInp.current.select();
     }
-  }, []);
+  }, [acsUrl]);
 
   const handleChange = (e: FormEvent<HTMLInputElement | HTMLSelectElement>): void => {
     const { name, value } = e.currentTarget;
@@ -75,7 +76,8 @@ export default function Login() {
       <div className='relative top-20 mx-auto w-[465px] max-w-[90%] rounded-md border p-10 text-[#145698]'>
         <h2 className='mb-3 text-center text-3xl font-bold'>Login</h2>
         <form onSubmit={handleSubmit}>
-          {acsUrl ? null : (
+          {isRouteReady ? (
+            acsUrl ? null : (
               <div>
                 <div className='mt-5'>
                   <label htmlFor='acsUrl' className='mb-2 block'>
@@ -109,7 +111,8 @@ export default function Login() {
                   />
                 </div>
               </div>
-          )}
+            )
+          ) : null}
           <div className='mt-5 flex items-end gap-x-1'>
             <div>
               <label htmlFor='username' className='mb-2 block'>