Creating Apps for a Global Audience

Good morning. Wow. Thank you. Thank you, very much. And once again, welcome to your first session at WWDC. My name is Joaquim. I don't think I have to reintroduce myself. Karan, Dongyuan, and I are really excited to talk to you about internationalization, at long last. So, what are we going to talk about? I'm going to do a brief introduction, like I started doing. And we're also going to do some deep dives on making your app's layout adaptive. And also, cover some really fun discussions on text, as well. So, why is this important? This applies to every single app. Internationalization is a crucial concept and we're going to go over some of the details as to why it applies to every single app, regardless of the set of languages that you support.

And once again, this is all about reaching out to more people. It's enabling everybody to learn about and use your app. Regardless of the language they speak or the country that they live in, or the country that they grew up in. And it's important to note that those last two might be different, as well. And that's something that's worth keeping in mind.

So, internationalization covers a wide range of topics, and potentially, every single aspect of your app. And if you're new to the topic, probably, the best way to think about it is that internationalization is best applied as a constant process. It's a discussion that belongs in every single stage of your app. Whether it's the initial inception, its design, to its implementation, and even distributing it on the App Store. Things like your App Store screenshots and even your app's name should be open for discussion in an international context. And like I said before, this covers a wide variety of topics.

At Apple, we have a lot of firsthand experience about this. So, we estimate that over 70% of our customers are outside of the United States. And this means that when somebody downloads your app they expect that app to match your language preferences. And not only that, but also, be aware of any details that might be related to their region settings, as well.

We support exactly 38 different written languages and many, many more keyboards and input methods for people to type and text. And what this means for you, is you have a rock solid foundation to get started with. Every single one of our API's supports these languages and input methods. And this means that you can get started right away by using these and you're off to a great start in providing really great international support to your app.

So, for example, this might entail presenting dates and times. This wouldn't be an international talk if I didn't talk about dates and times. But it's important to think about, right? Because people have different expectations around the world.

This is the Sao Bento in Portugal. It's a lovely train station. But my focus today isn't so much the train station as much as the way the times are presented in the train station. And if you go there, you might notice that everything is in 24-hour time. And this is true, not just in train stations, but it's commonplace everywhere in many countries.

And so, your app should know about these and present time accordingly, depending on the region. And you can do this using date formatter. It's a set of APIs we provide that lets you do this. And it really does all the heavy lifting for you. Another example is calendars. There are many different calendrical systems around the world. And it's also important to note that many people use more than one on a daily basis. They might use one for religious or festive events and another for business. And these all have different properties like leap months and leap years and different numbers of days and different numbers of months. And so, being precise about these and knowing how to present these appropriately means being internationally aware.

This is an example of the iOS Calendar app showing the Chinese Lunar calendar on top of the Gregorian calendar. And we have a set of API's in Calendar and alongside Date Formatter that help you do this.

Could also talk about units and measurements. Whether it's presenting things in the metric versus the imperial system, or even temperatures like Celsius or Fahrenheit.

Your app should be aware of the appropriate regional defaults for these, and also, respond to changes in the user's preference. And not only that, whether they're units or not, even numbers themselves. There are so many things to cover there from the decimal separator to the thousand separator. And even, the entire class of digits used to represent and talk about numbers. These can change between regions. And if you use number formatters, your app gets this behavior for free. And this is important not only for consistency, but also, understandability. Text is, also, another great topic with many different areas. And depending on the language or languages that you grew up learning and writing, and the scripts that those language are written in. You might have thought that there are some properties that are completely immutable across other scripts and other languages. And that might not, necessarily, hold. One example, probably the biggest example, is script directionality. So, some languages, like Arabic and Hebrew, and in this case Urdu, are written and read from right to left. Which, is completely the other way from English, from what you might be used to.

And taking this further, many books, most books published in traditional Chinese and Japanese are presented in vertical and right to left. And so, knowing about these formats and knowing about the context in which it's appropriate to present these and adapting your layout for these could be an important aspect of your app. And are why frameworks alongside our text frameworks like TextKit and CoreText can help you make sure you're doing the right thing in every single one of these cases. Going a little bit higher level, even things like names. Depending on where you grew up, you might have a first, middle, and last name. Or a family name that comes before your given name.

And again, knowing how to present these, and even asking your user about these could be a crucial part of your app. And this is something that users expect that you get right and know about the details and intricacies of formatting names.

And we have PersonNameComponentsFormatter API that help you do this.

Okay. So, throughout all of these concepts it's also important to note that many of the users might interact with and speak more than one language on a daily basis. Whether it's because they moved countries, or simply because that region, in and of itself, uses more than one language. And taking this example further, even if your app only supports one language it's very likely that your customers are using your app to publish and consume content in their own native language. And so, regardless of the set of languages that your app supports, these are all still very important topics to consider and talk about throughout the design and implementation of your app.

So, if all of this is new to you, worry not. Like I said before, we have a great set of APIs that really do all the heavy lifting for you and take care of all these different aspects. And are aware of all the different details between languages and regions. These are some examples of the Formatter APIs that I talked about. And we've, also, got some great sessions that go into great detail on how to further tailor these for your app, as well. So, let's start our first deep dive in to layout and some of the goals related to internationalization when it comes to adaptive layouts.

Because, really, the core goal of an adaptive layout is to present all kinds of different information.

And when you're adapting your application for other languages, probably, the biggest guarantee that you'll get is that these translation lengths are going to be different. They're going to be much shorter or much longer, depending on the language. And this is something that your design and layout should adapt for.

On top of this, there's also directionality, like I mentioned before. Because some languages are written in right to left this has some design considerations, not just in the text that you have in your app, but also, the way you present information. Especially, horizontally flowing