Registro Elettronico Spaggiari Enanched.user.js

/* jshint esnext: true */

// ==UserScript==
// @name         Registro Elettronico Spaggiari Enanched
// @namespace    https://web.spaggiari.eu/
// @version      0.1
// @description  New functions for the grade page.
// @author       Andrea Cognolato
// @match        https://web.spaggiari.eu/cvv/app/default/genitori_voti.php
// @grant        none
// @require http://code.jquery.com/jquery-2.1.4.min.js
// ==/UserScript==

function grade_to_float(grade) {
    let table = {
        '10': 10,
        '9/10': 9.75,
        '9½': 9.5,
        '9+': 9.25,
        '9': 9,
        '8/9': 8.75,
        '8½': 8.5,
        '8+': 8.25,
        '8': 8,
        '7/8': 7.75,
        '7½': 7.5,
        '7+': 7.25,
        '7': 7,
        '6/7': 6.75,
        '6½': 6.5,
        '6+': 6.25,
        '6': 6,
        '5/6': 5.75,
        '5½': 5.5,
        '5+': 5.25,
        '5': 5,
        '4/5': 4.75,
        '4½': 4.5,
        '4+': 4.25,
        '4': 4,
        '3/4': 3.75,
        '3½': 3.5,
        '3+': 3.25,
        '3': 3,
        '2/3': 2.75,
        '2½': 2.5,
        '2+': 2.25,
        '2': 2
    };
    return table[grade];
}

function createElem(mean) {
    let meanElement = document.createElement('td');
    let style = 'vertical-align: middle;';
    if (mean > 6) {
        meanElement.style = (style + 'color: green;');
    } else {
        meanElement.style = (style + 'color: red;');
    }
    meanElement.textContent = mean.toPrecision(4);
    meanElement.width = '350';
    meanElement.classList.add('registro');
    meanElement.classList.add('grautext');
    meanElement.classList.add('open_sans_condensed_bold');
    meanElement.classList.add('font_size_14');
    meanElement.align = 'left';

    return meanElement;
}

let grades = $('#data_table_2 tr').slice(4).map(function() {
    return $(this).find('.q3').find('p').map(function() {
        return $(this).text();
    });
});

let table = $('#data_table_2 tr').slice(4);

// Foreach subject
for (let i = 0; i < grades.length; i++) {
    // Get the grades for a subject
    let subject = grades[i];
    // Remove the empty ('') ones
    let real_grades = subject.filter((i) => subject[i] !== '').toArray();
    real_grades = real_grades.map(grade_to_float);

    if (real_grades.length === 0) continue;
    // Get the mean
    let mean = real_grades.reduce((a, b) => a + b, 0) / real_grades.length;

    // Add the element to the DOM
    table[i].appendChild(createElem(mean));
}