Bootstrap prepare page to print

source.js

var COLUMN_TYPES = ["col-sm-", "col-md-", "col-lg-"];
var mapToRevert = {};
var widthBefore = null;
var collapsedElements = null;

function beforePrint() {
    widthBefore = document.body.style.width;
    document.body.style.width = "600px";

    collapsedElements = $('.collapse');
    collapsedElements.removeClass('collapse');

    for(var i = 1; i <= 12; i++) {
        COLUMN_TYPES.forEach(function (columnType) {
            var className = columnType + i;
            var elems = $('.' + className);

            elems
                .toggleClass(className)
                .toggleClass("col-xs-" + i);

            mapToRevert[className] = {elems: elems, size: i};
        });
    }
}

function afterPrint() {
    document.body.style.width = widthBefore;

    collapsedElements.addClass('collapse');

    for(var className in mapToRevert) {
        if(mapToRevert.hasOwnProperty(className)) {
            var elems = mapToRevert[className].elems;
            var columnSize = mapToRevert[className].size;

            elems.addClass(className).removeClass("col-xs-" + columnSize);
        }
    }
}

if (window.matchMedia) {
    var mediaQueryList = window.matchMedia('print');
    mediaQueryList.addListener(function(mql) {
        if (mql.matches) {
            beforePrint();
        } else {
            afterPrint();
        }
    });
}

window.onbeforeprint = beforePrint;
window.onafterprint = afterPrint;