text: /*! echo.js v1.6.0 | (c) 2014 @toddmotto | https://github.com/toddmotto/echo */ ! function(t, e) {
      "function" == typeof define && define.amd ? define(function() {
          return e(t)
      }) : "object" == typeof exports ? module.exports = e : t.echo = e(t)
  }(this, function(t) {
      "use strict";
      var e, n, o, r, c, a = {},
          d = function() {},
          u = function(t, e) {
              var n = t.getBoundingClientRect();
              return n.right >= e.l && n.bottom >= e.t && n.left <= e.r && n.top <= e.b
          },
          l = function() {
              (r || !n) && (clearTimeout(n), n = setTimeout(function() {
                  a.render(), n = null
              }, o))
          };
      return a.init = function(n) {
          n = n || {};
          var u = n.offset || 0,
              i = n.offsetVertical || u,
              f = n.offsetHorizontal || u,
              s = function(t, e) {
                  return parseInt(t || e, 10)
              };
          e = {
              t: s(n.offsetTop, i),
              b: s(n.offsetBottom, i),
              l: s(n.offsetLeft, f),
              r: s(n.offsetRight, f)
          }, o = s(n.throttle, 250), r = n.debounce !== !1, c = !!n.unload, d = n.callback || d, a.render(), document.addEventListener ? (t.addEventListener("scroll", l, !1), t.addEventListener("load", l, !1)) : (t.attachEvent("onscroll", l), t.attachEvent("onload", l))
      }, a.render = function() {
          for (var n, o, r = document.querySelectorAll("img[data-echo], [data-echo-background]"), l = r.length, i = {
                  l: 0 - e.l,
                  t: 0 - e.t,
                  b: (t.innerHeight || document.documentElement.clientHeight) + e.b,
                  r: (t.innerWidth || document.documentElement.clientWidth) + e.r
              }, f = 0; l > f; f++) o = r[f], u(o, i) ? (c && o.setAttribute("data-echo-placeholder", o.src), null !== o.getAttribute("data-echo-background") ? o.style.backgroundImage = "url(" + o.getAttribute("data-echo-background") + ")" : o.src = o.getAttribute("data-echo"), c || o.removeAttribute("data-echo"), d(o, "load")) : c && (n = o.getAttribute("data-echo-placeholder")) && (null !== o.getAttribute("data-echo-background") ? o.style.backgroundImage = "url(" + n + ")" : o.src = n, o.removeAttribute("data-echo-placeholder"), d(o, "unload"));
          l || a.detach()
      }, a.detach = function() {
          document.removeEventListener ? t.removeEventListener("scroll", l) : t.detachEvent("onscroll", l), clearTimeout(n)
      }, a
  });
  