Messenger

function attachEvents() {
    $('#submit').click(send);
    $('#refresh').click(refresh);

    let hostUrl = "https://ajaxdemos-bfee6.firebaseio.com/messenger.json";

    function send() {
            let message = {
                author: $("#author").val(),
                content: $("#content").val(),
                timestamp: Date.now()
            };
        if(message.author!='' && message.content!=''){
            $.ajax({
                method: 'POST',
                data: JSON.stringify(message),
                url: hostUrl,
                success: function () {
                    $("#content").val('');
                    refresh()
                }
            });
            // $.post(hostUrl, JSON.stringify(message)).then(function(){
            //     $("#content ").val('');
            //     refresh();
            // });

        }

    }

    function refresh() {
        $.get(hostUrl)
            .then(function (result) {
                $('#messages').empty();
                let keys = Object.keys(result).sort((m1, m2)=> result[m1].timestamp - result[m2].timestamp);
                for (let msg of keys) {
                    $('#messages').append(`${result[msg].author} : ${result[msg].content}\n`)
                }
            })
    }
}