Vue Js Username and Password Validation

<!DOCTYPE html>
<html lang="en">
<head>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <h3>Vue Js Username and Password Validation</h3>
        <form>
            <label>
                Username:
                <input type="text" v-model="username" />
            </label>
            <label>
                Password:
                <input type="password" v-model="password" />
                <div v-if="password !== ''">
                    Password strength: {{ passwordStrength }}
                </div>
            </label>
            <button @click.prevent="submitForm">Submit</button>
            <p v-if="showValidationMessage">{{ validationMessage }}</p>
        </form>
    </div>

<script type="module">
        const app = new Vue({
            el: "#app",
            data() {
                return {
                    username: "",
                    password: "",
                    showValidationMessage: false,
                    minUsernameLength: 3,
                    maxUsernameLength: 20,
                    minPasswordLength: 8,
                    maxPasswordLength: 30,
                };
            },
            methods: {
                submitForm() {
                    if (this.isValid()) {
                        // Perform form submission logic
                    } else {
                        this.showValidationMessage = true;
                    }
                },
                isValid() {
                    if (
                        this.username.length < this.minUsernameLength ||
                        this.username.length > this.maxUsernameLength ||
                        this.password.length < this.minPasswordLength ||
                        this.password.length > this.maxPasswordLength
                    ) {
                        return false;
                    }
                    // Use regular expressions to check the format of the username and password
                    // Return false if the format is invalid
                    if (!/^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{8,}$/.test(this.password)) {
                        this.validationMessage = "Password must contain at least 1 letter and 1 number";
                        return false;
                    }
                    return true;
                },
                checkPasswordStrength() {
                    // Use a password strength library or regular expressions to determine the strength of the password
                    // Update the passwordStrength computed property with a string that describes the strength of the password
                    let passwordStrength = "Weak";
                    if (/(?=.*[A-Z])(?=.*[a-z])(?=.*\d).{8,}/.test(this.password)) {
                        passwordStrength = "Strong";
                    } else if (/(?=.*[a-zA-Z])(?=.*\d).{6,}/.test(this.password)) {
                        passwordStrength = "Medium";
                    }
                    return passwordStrength;
                },
            },
            computed: {
                validationMessage() {
                    let message = "";
                    if (this.username.length < this.minUsernameLength) {
                        message += `Username must be at least ${this.minUsernameLength} characters long. `;
                    }
                    if (this.username.length > this.maxUsernameLength) {
                        message += `Username must be less than ${this.maxUsernameLength} characters long. `;
                    }
                    if (this.password.length < this.minPasswordLength) {
                        message += `Password must be at least ${this.minPasswordLength} characters long. `;
                    }
                    if (this.password.length > this.maxPasswordLength) {
                        message += `Password must be less than ${this.maxPasswordLength} characters long. `;
                    }
                    return message;
                },
                passwordStrength() {
                    return this.checkPasswordStrength();
                },
            },
        });
    </script>
    <style scoped>
        /* Style for the form container */
        #app {
            max-width: 400px;
            margin: 0 auto;
            padding: 30px;
            background-color: #fff;
            border-radius: 10px;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }

/* Style for the labels */
        label {
            display: block;
            margin-bottom: 10px;
            font-weight: bold;
            color: #333;
        }

/* Style for the inputs */
        input[type="text"],
        input[type="password"] {
            display: block;
            width: 100%;
            padding: 12px;
            margin-bottom: 20px;
            border-radius: 5px;
            border: 1px solid #ccc;
            background-color: #f2f2f2;
            font-size: 16px;
            color: #333;
        }

/* Style for the password strength */
        div {
            margin-top: 10px;
            font-style: italic;
            color: #888;
            font-size: 14px;
        }

/* Style for the button */
        button {
            display: inline-block;
            padding: 12px 20px;
            margin-top: 20px;
            border-radius: 5px;
            border: none;
            background-color: #4CAF50;
            color: #fff;
            font-size: 16px;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }

button:hover {
            background-color: #3e8e41;
        }

/* Style for the validation message */
        p {
            margin-top: 10px;
            color: #d50000;
            font-size: 14px;
            font-weight: bold;
            text-align: center;
        }
    </style>
</body>

</html>