Return pages of text based on available space

textToPages.js

/*
 * 
 * Use: 
 * var textPages = textToPages(myElement)
 * returns array of strings.
 * 
 */
 
var textToPages = function(element) {
    var pages = [];
    var availableHeight = element.parentNode.clientHeight;
    var lineHeight = parseInt(window.getComputedStyle(element).lineHeight)
    var linesMax = Math.floor(availableHeight / lineHeight);
    var words = element.innerHTML.split(' ');
    var lines = element.clientHeight / lineHeight;

    // Using line-height and available height, work out approximately how many
    // words to fill a page. More efficient than going one by one.
    var approxLength = Math.floor((linesMax / lines) * words.length);

    // Our element for injecting content and performing experiments upon.
    var test = element.cloneNode(true);
    element.parentNode.appendChild(test);

    // Add approx content, then either add or remove words until the limit passed.
    // Then take away the one that bust the limit and it's as close as possible. 
    var addPage = function() {
        test.innerHTML = words.splice(0, approxLength).join(' ');
        
        var tooSmall = false;
        var tooLarge = false;
        var word = '';

        var cap2 = 0;
        do {
            cap2 ++;
            if (cap2 > 100) {
                console.log('Infinite loop avoided.');
                break;
            }

            // If less, add more words
            if (test.clientHeight <= availableHeight) {
                tooSmall = true;
                
                // If was too large to begin with, upon reaching here,
                // one less than limit has been found.
                if (tooLarge) break;

                // If there are no more words, our work is done.
                if (words.length == 0) break;

                // Add one word
                test.innerHTML += ' ' + words.splice(0, 1);
            } else {
                tooLarge = true;

                // Remove one word
                word = test.innerHTML.slice(test.innerHTML.lastIndexOf(' '));
                test.innerHTML = test.innerHTML.substring(0, test.innerHTML.lastIndexOf(' '));

                // Put word back with remaining
                words.unshift(word)
            }

        // Repeat until both true
        } while (!tooSmall || !tooLarge)

        pages.push(test.innerHTML);
    }

    var cap = 0;
    do {
        cap ++;
        if (cap > 100) {
            console.log('either there is over 100 pages or something has gone wrong.');
            break;
        }

        addPage();

    // Repeat while words remain
    } while (words.length > 0);

    element.parentNode.removeChild(test);
    test = null;
    return pages;
}