serialize-form.js

// [JS - serialize form]
function serialize(form) {
    if (!form || form.nodeName !== "FORM") {
        return;
    }
    var i, j, q = [];
    for (i = form.elements.length - 1; i >= 0; i = i - 1) {
        if (form.elements[i].name === "") {
            continue;
        }
        switch (form.elements[i].nodeName) {
        case 'INPUT':
            switch (form.elements[i].type) {
            case 'text':
            case 'hidden':
            case 'password':
            case 'button':
            case 'reset':
            case 'submit':
                q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].value));
                break;
            case 'checkbox':
            case 'radio':
                if (form.elements[i].checked) {
                    q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].value));
                }
                break;
            }
            break;
        case 'file':
            break;
        case 'TEXTAREA':
            q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].value));
            break;
        case 'SELECT':
            switch (form.elements[i].type) {
            case 'select-one':
                q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].value));
                break;
            case 'select-multiple':
                for (j = form.elements[i].options.length - 1; j >= 0; j = j - 1) {
                    if (form.elements[i].options[j].selected) {
                        q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].options[j].value));
                    }
                }
                break;
            }
            break;
        case 'BUTTON':
            switch (form.elements[i].type) {
            case 'reset':
            case 'submit':
            case 'button':
                q.push(form.elements[i].name + "=" + encodeURIComponent(form.elements[i].value));
                break;
            }
            break;
        }
    }
    return q.join("&");
}

// [JS - serialize to JSON]
function serializeToJSON(form) {
    let result = {};
    if (!form || form.nodeName !== "FORM") {
        return;
    }
    var i, j = [];
    for (i = form.elements.length - 1; i >= 0; i = i - 1) {
        if (form.elements[i].name === "") {
            continue;
        }
        switch (form.elements[i].nodeName) {
        case 'INPUT':
            switch (form.elements[i].type) {
            case 'text':
            case 'hidden':
            case 'password':
            case 'button':
            case 'reset':
            case 'submit':
                result[form.elements[i].name] = form.elements[i].value;
                break;
            case 'checkbox':
            case 'radio':
                if (form.elements[i].checked) {
                    result[form.elements[i].name] = form.elements[i].value;
                }
                break;
            }
            break;
        case 'file':
            break;
        case 'TEXTAREA':
            result[form.elements[i].name] = form.elements[i].value;
            break;
        case 'SELECT':
            switch (form.elements[i].type) {
            case 'select-one':
                result[form.elements[i].name] = form.elements[i].value;
                break;
            case 'select-multiple':
                for (j = form.elements[i].options.length - 1; j >= 0; j = j - 1) {
                    if (form.elements[i].options[j].selected) {
                        result[form.elements[i].name] = form.elements[i].options[j].value;
                    }
                }
                break;
            }
            break;
        case 'BUTTON':
            switch (form.elements[i].type) {
            case 'reset':
            case 'submit':
            case 'button':
                result[form.elements[i].name] = form.elements[i].value;
                break;
            }
            break;
        }
    }
    return result;
}