upccrt/resources/js/views/Login.vue

<template>
    <div class="container">
        <div class="row justify-content-center">
            <div class="col-md-8">
                <div class="card card-default">
                    <div class="card-header">Login</div>

                    <div class="card-body">
                        <form method="POST" action="/login">
                            <div class="form-group row">
                                <label for="username" class="col-sm-4 col-form-label text-md-right">Username</label>

                                <div class="col-md-6">
                                    <input id="username" type="username" class="form-control" v-model="username" required autofocus>
                                </div>
                            </div>

                            <div class="form-group row">
                                <label for="password" class="col-md-4 col-form-label text-md-right">Password</label>

                                <div class="col-md-6">
                                    <input id="password" type="password" class="form-control" v-model="password" required>
                                </div>
                            </div>

                            <div class="form-group row mb-0">
                                <div class="col-md-8 offset-md-4">
                                    <button type="submit" class="btn btn-primary" @click="handleSubmit">
                                        Login
                                    </button>
                                </div>
                            </div>
                        </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
</template>
<script>
    export default {
        data(){
            return {
                username : "",
                password : ""
            }
        },
        methods : {
            handleSubmit(e){
                e.preventDefault()

                if (this.password.length > 0) {
                    axios.post('api/login', {
                        username: this.username,
                        password: this.password
                        })
                        .then(response => {
                        localStorage.setItem('user',response.data.success.username)
                        localStorage.setItem('jwt',response.data.success.token)

                        if (localStorage.getItem('jwt') != null){
                            this.$router.go('/dashboard')
                        }
                        })
                        .catch(function (error) {
                        console.error(error);
                        });
                }
            }
        },
        beforeRouteEnter (to, from, next) { 
            if (localStorage.getItem('jwt')) {
                return next('dashboard');
            }

            next();
        }
    }
</script>