previewPic.js

/*
var script = document.createElement('script');
var p1 = encodeURIComponent("$('#data_list tr').find('td:eq(2) a')");
var p2 = encodeURIComponent('.intro img');

script.src = `https://rawgit.com/think2011/53fe08923ced04f10ca0/raw/4bad14cd67c835306d93a01b5ea377fe354081d1/previewPic.js?${p1}&${p2}`;
document.body.appendChild(script);
*/

jsReady(() => {
	var params = deUrlParams();

	previewPic(params[0], params[1]);
});

/**
 * 抓取链接中的第一张图并放到链接区域内
 *
 * @param allA {eval} 链接选择器源码串
 * @param firstImg 首图的选择器
 */
function previewPic(allA, firstImg) {
	eval(allA).each((k, v) => {
		var $a = $(v);

		$.get($a.attr('href'), function(data) {
			var img = $(data).find(firstImg)[0];
			img.style.width = '100%';
			$a.append(img);
		});
	});
}

/**
 * 从url中解析出参数
 * @return {[type]} [description]
 */
function deUrlParams () {
	var params = (document.scripts[document.scripts.length-2].src).split('?');

	params = params[1].split('&');

	return [decodeURIComponent(params[0]), decodeURIComponent(params[1])];
}

/**
 * 初始化脚本
 */
function jsReady(fn) {
	var script = document.createElement('script');
	script.src = 'http://cdn.bootcss.com/jquery/2.1.4/jquery.min.js';
	document.body.appendChild(script);

	script.onload = fn;
}