图片懒加载

var lazy = (function () {

var store = [],

offset,

throttle,

poll;

 

var _inView = function (el) {

var coords = el.getBoundingClientRect();

return ((coords.top >= 0 && coords.left >= 0 && coords.top) <= (window.innerHeight || document.documentElement.clientHeight) + parseInt(offset));

};

 

var _pollImages = function () {

for (var i = store.length; i--;) {

var self = store[i];

if (_inView(self)) {

self.src = self.getAttribute('data-src');

self.style.height = 'auto';

//修改腾讯视频连接地址

if(self.getAttribute('class')=='video_iframe' || self.getAttribute('class')=='video_iframe video_wrap'){

self.className = 'video_iframe video_wrap';

self.src = self.getAttribute('data-src').split("&")[0].replace("preview","player").replace("https","http");

}

store.splice(i, 1);

}

}

};

 

var _throttle = function () {

clearTimeout(poll);

poll = setTimeout(_pollImages, throttle);

};

 

var init = function (obj) {

var nodes = document.querySelectorAll('[data-src]');

var opts = obj || {};

offset = opts.offset || 0;

throttle = opts.throttle || 250;

for (var i = 0; i < nodes.length; i++) {

store.push(nodes[i]);

}

 

_throttle();

 

if (document.addEventListener) {

window.addEventListener('scroll', _throttle, false);

} else {

window.attachEvent('onscroll', _throttle);

}

};

return {

init: init,

render: _throttle

};

})();

 

lazy.init();