洋葱数学技术博客

anytojson is an npm widget for developers. It fetches CSV, JSON data from REST APIs, Flat Files etc and converts them to JSON.

hotJar is an analytic tool to visualize the user behavior. It’s another solution (and better, perhaps) toward point burying for data collecting and analysis. The most amazing effect is its heatmap, like

We have introduced watermarks to our videos, now we can do the same thing on our site.

Simply using Watermark.js, with some lines of code, we can deploy image/text as watermark on site, and sets its transparency.

This is libook‘s project.

AutoZoom(Source Code) is a chrome extension can automatically zoom in and scroll. Let me just see the whole area of main content.

Initially, AngularJS is famous for its two-way data binding mechanism. Now there is a jQuery way to realize, that is jQuerymy.

At May 5, io.js has released v2.0.0 with upgraded V8 engine (v4.2.2) and other notable changes (see its changelog).

#CSS methodology

##author Luowei

CSS编程有4个维度分别是: patterns/implementation/ideologies/methodology,我将逐一介绍这四个维度，并重点介绍methodology。

###Patterns
Patterns 是需要我们用从可视化设计中抽象出来并需要用CSS去编码的对象。有些模式是可以复用的，采用原子设计的方式，从原子->分子->组织->模板->页面，这是一个从抽象到具体的过程。

如过使用副本集且mongos为1.7.4或更高版本,把读操作分散从机上,便会遇到”not master”错误.

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> show dbs;
> Error: listDatabases failed:{ "note" : "from execCommand", "ok" : 0, "errmsg" : "not master" }
> rs.slaveOk();

很久的一篇文章了，之所以转有几方面原因：

1. 最近有同学问了相同的问题，异常处理到底需要写到什么程度，我一时语塞，不知从何答起，在码农周刊中偶然发现这篇文章，正好回答问题

###查询性能优化Tips:

• 涉及排序操作使用索引.
• MongoDB使用Btree索引,涉及到范围的索引,应该尽可能放在符合查询逻辑的最后面.