var vm = new Vue({
    el: '#app',
    data: {
        message: "This is local data.",
    },
    methods: {
        getRemoteMessage() {    // 2. trigger event in Vue instance
            Promise.resolve("Get remote data by inside button.") // 3. Get data asynchronously
                .then((res) => {    // 4. Return result
                    this.message = res; // 5. Change View Model
                });
        },
    },
});

function clickButton() {    // 2. trigger event in Vue instance
    Promise.resolve("Get remote data by outside button.") // 3. Get data asynchronously
        .then((res) => {    // 4. Return result
            vm.message = res; // 5. Change View Model
        });
}