CoreID/app/assets/app/auth/login/Form.component.js

import { Component } from '../../../lib/vues6/vues6.js'
import { auth_api } from '../../service/AuthApi.service.js'
import { location_service } from '../../service/Location.service.js'

const template = `
<div class="coreid-login-form col-lg-6 col-md-8 col-sm-10 col-xs-12 offset-lg-3 offset-md-2 offset-sm-1 offset-xs-0 text-left">
    <div class="coreid-login-form-inner">
        <div class="coreid-login-form-header font-weight-light">{{ app_name }}</div>
        <div class="coreid-login-form-message">{{ login_message }}</div>
        <form class="coreid-form" v-on:submit.prevent="do_nothing">
            <div class="form-group">
                <input
                    type="text"
                    id="coreid-login-form-username"
                    name="username"
                    class="form-control"
                    placeholder="Username"
                    v-model="username"
                    autofocus
                    @keyup="on_key_up"
                    :disabled="loading || step_two"
                >
            </div>
            <div class="form-group" v-if="step_two">
                <input 
                    type="password" 
                    id="coreid-login-form-password" 
                    name="password" 
                    class="form-control" 
                    placeholder="Password"
                    v-model="password"
                    :disabled="loading"
                    @keyup="on_key_up"
                    ref="password_input"
                >
            </div>
            <div v-if="error_message" class="error-message">{{ error_message }}</div>
            <div v-if="other_message" class="other-message">{{ other_message }}</div>
            <div class="buttons text-right">
                <button type="button" class="btn btn-primary" :disabled="loading" v-if="step_two" v-on:click="back_click">Back</button>  
                <button type="button" class="btn btn-primary" :disabled="loading || btn_disabled" v-on:click="step_click">{{ button_text }}</button>  
            </div>
        </form>
        <div class="coreid-loading-spinner" v-if="loading"><div class="inner"></div></div>
    </div>
</div>
`

export default class AuthLoginForm extends Component {
    static get selector() { return 'coreid-login-form' }
    static get props() { return [
        'app_name', 'login_message', 'additional_params', 'no_session',
    ] }
    static get template() { return template }

    username = ''
    password = ''
    button_text = 'Next'
    step_two = false
    btn_disabled = true
    loading = false
    error_message = ''
    other_message = ''

    watch_username(new_username, old_username) {
        this.btn_disabled = !new_username
    }

    back_click() {
        this.step_two = false
        this.button_text = 'Next'
    }

    async on_key_up(event) {
        if ( event.keyCode === 13 ) {
            // Enter was pressed
            event.preventDefault()
            event.stopPropagation()
            if ( !this.step_two && this.username ) return this.step_click(event)
            else if ( this.step_two && this.username && this.password ) return this.step_click(event)
        }
    }

    async step_click(event) {
        if ( !this.step_two ) {
            this.loading = true
            try {
                const is_valid = await auth_api.validate_username(this.username)
                if ( !is_valid ) {
                    this.error_message = 'That username is invalid. Please try again.'
                } else {
                    this.step_two = true
                    this.button_text = 'Continue'
                    this.error_message = ''
                    this.$nextTick(() => {
                        this.$refs.password_input.focus()
                    })
                }
            } catch (e) {
                this.error_message = 'Sorry, an unknown error has occurred and we are unable to continue at this time.'
            }
            this.loading = false
        } else {
            this.loading = true
            this.error_message = ''

            let attempt_vars = {
                username: this.username,
                password: this.password,
                create_session: !this.no_session,
            }

            if ( typeof this.additional_params === 'object' ) {
                attempt_vars = {...attempt_vars, ...this.additional_params}
            }

            const result = await auth_api.attempt(attempt_vars)
            if ( !result.success ) {
                this.error_message = result.message || 'Sorry, an unknown error has occurred and we are unable to continue at this time.'
                this.loading = false
                return
            }

            this.other_message = 'Success! Let\'s get you on your way...'
            await location_service.redirect(result.next, 1500)
        }
    }

    do_nothing() {}
}