Actions

week03/app/controllers/login.js

 import Controller from '@ember/controller';
 import { tracked } from '@glimmer/tracking';
+import { action } from '@ember/object'
 
 export default class LoginController extends Controller {
     @tracked email = '';
     @tracked password = '';
+    @tracked loginInvalid = false;
+    classLabel = 'is-invalid-label';
+
+    @action
+    login(event) {
+        event.preventDefault();
+        if(this.email === 'test@example.com' && this.password === 'password') {
+                this.loginInvalid = false;
+            } else {
+                this.loginInvalid = true;
+            }
+    }
+
+    @action
+    typing() {
+        this.loginInvalid = false;
+    }
 }

week03/app/templates/login.hbs

 <div class="grid-x grid-padding-x">
-  <form class="cell large-2 large-offset-5">
+  <form class="cell large-2 large-offset-5" {{on "submit" this.login}}>
     <div class="callout">
         <h1>Login</h1>
-        <label>E-Mail
-            <Input type="email" @value={{this.email}} />
-            <span class="form-error is-visible">No user exists with this e-mail address {{this.email}} or the password is not correct.</span>
+        <label class={{if loginInvalid this.classLabel}}>E-Mail
+            <Input type="email" @value={{this.email}} class={{if loginInvalid this.classInput}} {{on "keypress" this.typing}}/>
+            {{#if loginInvalid}}
+                <span class="form-error is-visible">No user exists with the e-mail address {{this.email}} or the password is incorrect.</span>
+            {{/if}}
         </label>
-        <label>Password
-            <Input type="password" @value={{this.password}} />
-            <span class="form-error is-visible">No user exists with this e-mail address {{this.email}} or the password is not correct.</span>
+        <label class={{if loginInvalid this.classLabel}}>Password
+            <Input type="password" @value={{this.password}} class={{if loginInvalid this.classInput}} {{on "keypress" this.typing}} />
+            {{#if loginInvalid}}
+                <span class="form-error is-visible">No user exists with the e-mail address {{this.email}} or the password is incorrect.</span>
+            {{/if}}
         </label>
         <div class="text-right">
             <button class="button">Login</button>