Update b-field message after button click

I'm very new in Vue, and I'm trying to do a simple thing of displaying the result in a b-field after clicking a button.

Below is my Login.vue code

<template>
    <section id="login">
        <h1>Login</h1>
        <b-field label=""
            type="is-warning"
            message="Please enter a valid email">
            <b-input type="email" name="email" v-model="input.email" placeholder="E-mail"></b-input>
        </b-field>
        <b-field label=""
            type="is-warning"
            message="Please enter your password">
            <b-input type="password" name="password" v-model="input.password" placeholder="Password"></b-input>
        </b-field>
        <b-field message="hohoho"
            type="is-danger"
            name="result"
            >
            <button type="button" v-on:click="login()" class="button">Login</button>
        </b-field>
    </section>
</template>

<script>
    export default {
        name: 'Login',
        data () {
            return {
                input: {
                    email: "",
                    password: ""
                }
            }
        },
        methods: {
            login () {
                if(this.input.email != "" && this.input.password != "") {
                    if(this.input.email == this.$parent.mockAccount.email && this.input.password == this.$parent.mockAccount.password) {
                        this.$emit("authenticated", true)
                        this.$router.replace({ name: "secure" })
                    } else {
                        this.result = "The email and / or password is incorrect"
                        console.log("The email and / or password is incorrect")
                    }
                } else {
                    this.result = "An email and password must be present"
                    console.log("An email and password must be present")
                }
            }
        }
    }
</script>

I have problem updating the content of the b-field with name result... the this.result doesn't update the content of the b-field.

I guess you want to update the message attribute of this element?

<b-field message="hohoho"
            type="is-danger"
            name="result">
            <button type="button" v-on:click="login()" class="button">Login</button>
</b-field>

If I am correct you just need to bind the result prop to the message attribute like this:

<b-field :message="result"
            type="is-danger"
            name="result">
            <button type="button" v-on:click="login()" class="button">Login</button>
</b-field>

Notice the :message="result", it's a shortcut for v-bind:message="result".

Also, very important, you need to define the result prop in data

data () {
    return {
        input: {
            email: "",
            password: ""
        },
        result: ""
    }
},

More info here