script.js

var preguntas;
var pregunta;
var respuestas;
var buffer = "";
var result = false;

function loadWord(){
    if(preguntas === undefined || preguntas.length < 3){
        // Asynchronously get the word that will be displayed on the next call
        $.ajax({
            url: '/api/getWord/?num_words=20',
            type: 'GET',
            dataType: 'json',
            success: function(json){
                preguntas = json;
            }
        });
    }

    // Display the word that was previously buffered
    pregunta = preguntas[0]["word"];
    respuestas = preguntas[0]["translation"];
    preguntas.shift()
    if(pregunta.length > 0){
        $(".upper-span").text(pregunta);
        var el     = $(".upper-text"),
            newone = el.clone(true);
        el.addClass("toRemove");
        el.before(newone);
        $(".toRemove").remove();
    }
};

function sendResult(word, result){
    $.ajax({
        url: '/api/postResult/?word=' + word + '&result=' + result,
        type: 'GET',
        dataType: 'json'
    });
};

function captureBackspace(event){
    if(event.which == 8){
        buffer = buffer.substring(0, buffer.length - 1);
        $(".lower-span").text(buffer);
    }
};

function captureKeyboard(event){
    if(event.which == 13){
        $(".lower-span").removeClass("init");
        if(preguntas !== undefined && respuestas !== undefined){ // This is unnecessary if no word has been loaded yet, we are still displaying the first screen
            result = false;
            // Check the buffer against all available translations for a match
            respuestas.forEach(function (item, index){
                let norm = item.normalize("NFD").replace(/[\u0300-\u036f]/g, "").toLowerCase(); // Delete accents and change to lowercase
                if (buffer.toLowerCase() === norm){
                    result = true;
                }
            });
            sendResult(pregunta, result);
            if(result){
                $(".info-text span").text("Correct ! Réponses possibles : " + respuestas.toString());
                $(".info-text span").removeClass("incorrect");
            } else {
                $(".info-text span").text("Incorrect ! Réponses possibles : " + respuestas.toString());
                $(".info-text span").addClass("incorrect");
            }
        }
        buffer = "";
        loadWord();
    }
    var c = String.fromCharCode(event.which);
    var b = c.replace(/[^a-z0-9-! ]/gi,''); // Only allowing a simple character set
    buffer = buffer + b;
    $(".lower-span").text(buffer);
};

$(document).ready(function(){
    $(document).keypress(captureKeyboard);
    $(document).keydown(captureBackspace);
    loadWord();
});