#react native

After testing our React Native app on the simulator for a day or two we, similar to a young Kobe Bryant, decided to forgo college and take our talents to the big leagues, by testing our native app on an actual device.

This is a good practice because from a hardware standpoint you’re phone is a very different device than your Mac. Because of the more powerful CPU in your computer there is always the chance that applications that run seamlessly on the Computer’s simulator run choppy on an actual device.

For our purposes we wanted to ensure that our react Native components looked and felt native on a device, and that the positive results produced on the simulator were not just a fluke.

The Nitty Gritty

In our experience the process of getting an App on an actual device is somewhat painful. To help you avoid the same pitfalls that caused us headaches we wanted to give you some solutions to the most common problems you will run into while trying to get your app on your device.

  1. Setting up your iOS developer account: First and foremost it is import to correctly configure your iOS developer account so that you can run your application on an iOS device. This step is easily the most painful part of the process because of how much outdated information that exists on this subject. After poking around for a bit this was the most helpful tutorial that we could find – How to Deploy your App on an iPhone
  2. Plugin your device and ensure that your Xcode and iOS versions are compatible: Right after your developer account is setup the next step is to check and make sure that you are running compatible versions of Xcode and iOS. If not then you will be given an error saying, “The Developer Disk Image could not be mounted”. The simplest fix for this issue is to always make sure that you are running the most recent versions of Xcode and iOS. However, if for some reason you do not want to update your version of Xcode another fix would be to set the deployment target of your application to a version equal to or behind the current version of iOS running on your phone.
  3. Accessing the development server from the device: Now that your app is installed on your device feel free to open it up and navigate through it’s screen. However, if the app needs to make calls to a server running locally on your computer then you are going to have to connect your app to that server. The fastest way to do this is to update the AppDelegate.m file and change the IP in the URL form localhost to your laptop’s IP address. For more information on this step checkout the react documentation at – Running On Device – React Native

Posted In: Javascript

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Here at Setfive, when not helping our clients with their technology woes, we love experimenting with fun new technology and continuously growing our professional tool kit. As of late we have been throwing around some potential ideas for a Setfive iPhone app (get Chicken Pad Thai delivered no matter where you are in the world) and have been looking at a couple of tools to turn this lofty dream into a reality.

Since no one in the office has any significant experience with Objective C or Swift we decided that, rather than bang our heads against the wall trying to learn the nuances of yet another programming language, we would look to one that we already know, and decided to dip our toes into the JavaScript driven React Native ecosystem.

In the past we have taken our chances with other cross-platform native apps (PhoneGap in particular) that allow you to wrap a web app into a web view however, these methods fall short; if the looks of your app don’t bother you then the serious performance hit that comes from interfacing directly with native objects will.

If you are unfamiliar with React Native, it’s an open source JavaScript framework, built by Facebook, that allows the production of iOS and Android applications using a syntax familiar to HTML. What separates React from other frameworks is that it runs a separate JavaScript thread to control the UI of your application so it can utilize native mobile components. The idea is that this should lead to a seamless user experience that feels both polished and native. After some hands on experience we can say that React did not disappoint.

What we built

In order to test React a little bit farther than the simple hello world example we decided to build a simple application on top of our preexisting Rotorobot API. This app allows users to see the available players for a daily fantasy sports contest on that night.

To get started, we needed an index page that would show up when the app was loaded. Just to keep things simple we incorporated a minimalist layout with a UIButton that responds when pressed.

Upon pressing the button a new scene is added to the storyboard of our application. This scene is a ListView Component that has a row for every available slate of games that will be played that night. In addition, each one of these rows is also wrapped in a TouchableHighlight Component, which allows them to respond to touches.

Any row that you touch results in an AJAX request being made to the Rotorobot API and the available players in that slate are displayed, sorted in descending order based on salary.

Our Experience

Getting something up and running with React Native was definitely a lot easier than expected. It was honestly as simple as using npm to install react-native-cli and then creating a new react native project using react-native init. The init function provides everything that you need to run a React Native application.

After your project has been setup it’s time for all of you Xcode naysayers to either bite the bullet and download Xcode or look for guidance in the form of another SaaS solution.

In order to help you out we’ve provided links to a couple:

If you’re old fashioned like us, and opted for the traditional route then you installed X-Code. The react-native init function creates an Xcode project file inside the ios folder in your new project’s directory. Simply open this up using Xcode and you are off to the races and ready to build/run your project at will.

There was only one minor gotcha that reared it ugly head while trying to get our application up and running. The React Native Packager runs underneath node and requires a port for its functionality. The default port that it runs on is 8081, and there is a chance that you could have a process already running on that port so your application will not be able to run. So before you try and run your Xcode project for the first time it is worth doing a quick check to make sure that port 8081 is free using:

sudo lsof -i :8081

Other than this minor inconvenience you should be all set for development!

After an hour or two of playing with React Native and building a pretty simple app, the power and simplicity of this framework became clear to us. First and foremost it was very refreshing to only have to run one or two npm commands and then be writing code in minutes afterwards. Setup was quick and painless which is always appreciated. During development we immediately noticed that developing our app felt just like developing for the web. Laying out the application was done using the CSS flex box, and was both quick and intuitive. Additionally, and probably more importantly, the framework just works. The UI components are native UIViews so naturally they look, feel, and behave the same as normal native components. We would definitely consider using React in the future and look forward to seeing how it improves and progresses from here.

Posted In: Javascript

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