Translation tool - apply pseudotranslations to text in HTML files

translation-tool.js

document.addEventListener('DOMContentLoaded', function() {
    var translateButton = document.createElement('button');
    translateButton.innerHTML = 'Translate';
    translateButton.addEventListener('click', processPageForTranslation);
    translateButton.setAttribute("style", "position: fixed; top: 0; left: 0; opacity:.5; z-index: 1000;");
    translateButton.setAttribute('data-exclude-pseduotranslation', '');
    document.getElementsByTagName('body')[0].appendChild(translateButton);
}, false);

function isAllWhitespace(childNode) {
    return !(/[^\t\n\r ]/.test(childNode.textContent));
}

function shouldExcludeElement(element) {
    return element.hasAttribute('data-exclude-pseduotranslation');
}

function processPageForTranslation() {
    var elementsToTranslate = [];
    var allBodyChildren = document.getElementsByTagName('body')[0].getElementsByTagName('*');

    for (var c = 0; c < allBodyChildren.length; c++) {
        if (!shouldExcludeElement(allBodyChildren[c])) {
            elementsToTranslate.push(allBodyChildren[c]);
        }
    }

    for (var i = 0; i < elementsToTranslate.length; i++) {
        var childNode = elementsToTranslate[i].childNodes;

        for (var j = 0; j < childNode.length; j++) {
            if (childNode[j].nodeType === Node.TEXT_NODE) {
                if (!isAllWhitespace(childNode[j])) {
                    translateString(childNode[j]);
                    break;
                }
            }
        }
    }

    function translateString(itemToTranslate) {
        var factor;

        itemToTranslate.textContent = itemToTranslate.textContent.trim();

        // The factor is used to calculate a string's expansion for pseudotranslation
        if (itemToTranslate.length <= 3) {
            factor = 3;
        } else if (itemToTranslate.length > 3 && itemToTranslate.length <= 11) {
            factor = 2;
        } else {
            factor = 1.5;
        }

        // Expanded string length which helps determine how many extra characters to prepend and append to the original string
        var expansionStringLength = itemToTranslate.textContent.length * (factor - 1);

        // The number of extra characters to add to the left and right of each string
        var sideExpansion = Math.ceil(expansionStringLength / 2);

        // You can replace 'x' with a wider character if you'd like
        var halfOfExpansionString =  Array(sideExpansion).join('x');

        // Add space after every 8th x
        halfOfExpansionString = halfOfExpansionString.replace(/(\S{8})/g, "$1 ");
        itemToTranslate.textContent = '[' + halfOfExpansionString + '-' + itemToTranslate.textContent + '-' + halfOfExpansionString + ']';
    }
}