Lesson Outline

Creating Production Builds

When you are creating the final build of your application, or when you are fine tuning performance, you need to make sure you supply the production flag when building:

--prod

It may seem a bit much to dedicate an entire lesson to this, but it is so critical to performance and I have so often seen people unaware of this that it is definitely worth spending some time on. We are going to spend a little time demonstrating what it does, and then we will talk about how it does it.

To give a solid example of how critical it is to include this flag, let's take a look at a performance profile of application start up time for the Hangz application from one of the other modules. We will look at one profile for a build that uses the --prod flag, and one that doesn't.

First, let's take a look at a build that was deployed to an iPhone using the following command:

ionic build

The application takes about 1.5 seconds to launch (which is certainly not bad, anywhere up to 3-4 seconds is quite good). You can tell where the application finishes loading by seeing where the Network Requests finish. You can ignore the additional Layout and Rendering as that is just an animation that plays after the login screen loads.

Now let's take a look at a build that was deployed to the same device, but using this command instead:

ionic build --prod