Use go tool pprof to profile memory usage of a Go app (to find memory leaks).

Fixing this error x509 failed to load system roots and no roots provided in a Docker container

When you build Docker images many times, you will find it is very necessary to manage images with tags.

Recently I deployed my node.js app, Redis, Postgres, Nginx with Docker and wrote a tutorial. I want to share you with some tricks and tips about Docker.

This post shows you how to restore and backup Postgres database which is running in a Docker container.

This tutorial introduces how to deploy a web app, Redis, Postgres and Nginx with Docker on the same server. In this tutorial, the web app is a node.js(express) app. We use Redis as a cache store, Postgres as the database, and Nginx as the reverse proxy server.

Emoji is very popular. I am making a keyboard which contains many Emojis. However, I found the memory usage of Emoji is too high. When the keyboard's memory usage is high enough, iOS will kill the keyboard immediately. (Looks like the limit is 40mb on iOS 8.3)

I deployed a node.js app on a server running on CentOS linux. I am using 'forever' to keep my node.js app alive. But when the server restarts, we need to let the app run automatically.

I made a new iPhone app and submitted to App Store. However, it is rejected because of 'Invalid Binary'.

SQLCipher is encrypted SQLite. The following are the steps to build it on Mac OS X.

If your app is an universal app and you changed the background colour of an UITableView, you will see it works on iPhone but does not work on iPad.

Sometimes, you see the following code of dismissing keyboard not working on iPad but working on iPhone [textField resignFirstResponder];

If your app is an universal app and you changed the background colour of an UITableView, you will see it works on iPhone but does not work on iPad.

As many Mac developer did to validate Mac app store receipt, I use roddi's code (https://github.com/roddi/ValidateStoreReceipt Thanks!). But recently I found it does not work! The code fails to validate the sample receipt.

Introducing how to debug Ruby on Rails app with Aptana Studio 3

Sometimes syntax highlighting does not work on Xcode 4. Syntax highlighting is an important feature to developers. But there is no "Rebuild Code Sense" menu on Xcode 4. We can do it with following steps

The default code set of Localizable.strings is UTF-16. Actually I don't care what code set it is. But git/gitX/SourceTree does not recognize UTF-16 (Stupid!). They treat UTF-16 Localizable.strings as a binary file and reject to diff or merge. This is a very big problem if you work in a team.

There is an annoying bug (or behavior) about non-English language keyboard on iOS 5.

Scrolling NSScrollView to top is more difficult than what it looks like.

proc_pidinfo is a very useful function to get a Mac OS X process's info such as the size of resident memory, consumed CPU time. However, sometimes, the returned info is not correct.

If you want to let your user post something from your app onto Facebook, you need to register a Facebook app and call Facebook SDK to post messages. But if you have a free version and a paid version, you would like to share the same Facebook App ID.

Using Git with Xcode 4

Add Tool Tip to Controls with Xcode4 on OS X

The way to stop UIView animations

An UIView of one of my iOS app shows a fade-in animation. I implemented this animation in viewDidLoad. When I was porting this app onto Mac OS X, I found there is no viewDidLoad.

Several steps to let a Mac App support full screen mode on OS X.

A tutorial of Implementing Fade-In Fade-Out animation in NSView on Mac OS X

Reduce the size of iPhone/iPad app.

When we do localizations, the problem is the words order of a language differs to other languages. For example, this sentence "Ted wants a scooter." may be something like "A Scooter is what Ted wants" in another language.

Core Animation for Mac OS X and the iPhone

Fixing a weird Time Machine error.

Apple just released Mac OS X 10.7 Lion developer preview. There are some new features inspired by iPad. The Launchpad looks like iOS springboard. The apps can run in the full-screen mode. You macbook with Lion will look like an iPad. However, many people including me only have one machine with Snow Leopard installed. We don't want our valuable data destroyed by the beta OS. It is not safe to upgrade the existing OS to Lion in the existing partition. Can we just install Mac OS X Lion on the external hard drive? Yes!