A work in progress to build a cross-platform video player for https://www.giantbomb.com, a website about video games.
- Run on the following platforms (chosen primarily because I own and use):
- Support browsing video content in multiple categories
- Stream both free and premium videos
- Sync video progress cross-platform and potentially sync with the Giant Bomb website itself
- Offline video support
- Support YouTube player for available content (may bring this up to V1 given the current buffering issues Giant Bomb has)
- Stream live content (might be easy, if so I'll bring into V1)
- Type system
- Support unit testing with 95% coverage minimum
- Continuous integration
- Track metrics in prod
- Errors
- Latency
- Free and open source
- As a consequence, I don't want to pay or support any services as part of this project
- Giant Bomb API
- How to authenticate using the Giant Bomb API
- Expo's SecureStore API for auth tokens
- Giant Bomb save-time API to save video progress
- React Native can be used to support all target platforms
- Redux can used to manage application state
- Expo framework can simplify/eliminate native development
- I have done a simple hello world test that works on iPhone and FireTV hardware
- Expo seems to work well and is free ATM, but not really sure how it's going to stay that way
- None of Expo's limitations impact the product goals
- It looks like Expo has CodePush like support out of the box... which is amazing
- Expo is open source and I can always eject the React Native app and create my own native apps if needed, so I'm not that worried about taking a dependency here
- Expo recommends using Sentry for error tracking and it should be easy to use the free tier given the scope of this project
- React Native for Windows can be used to support Window 10
- Travis CI can be used to perform integration builds and tests
- I can probably use the
exp
CLI to publish builds to https://expo.io - Found an interesting module called appr to generate Expo builds off pull-requests
- I can probably use the
- VSCode can be used for cross-platform development
- WSL can be used to support linux tooling on Windows
- WSL terminals can be used in VSCode
- Currently VSCode doesn't support running extensions in a WSL environment, so CLI development with limited IDE integration will be used on Windows
- TypeScript can be used with React Native
- Alternatively Flow can be used, but I'll try TypeScript first
- Jest will be used for unit tests
- For the first iteration I won't be using end-to-end automated device testing, largely for cost reasons
Neil Goodman (https://github.com/neilgoodman)
Copyright (c) 2018 Neil Goodman
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
This project was bootstrapped with Create React Native App.
Below you'll find information about performing common tasks. The most recent version of this guide is available here.
- Updating to New Releases
- Available Scripts
- Writing and Running Tests
- Environment Variables
- Adding Flow
- Customizing App Display Name and Icon
- Sharing and Deployment
- Troubleshooting
You should only need to update the global installation of create-react-native-app
very rarely, ideally never.
Updating the react-native-scripts
dependency of your app should be as simple as bumping the version number in package.json
and reinstalling your project's dependencies.
Upgrading to a new version of React Native requires updating the react-native
, react
, and expo
package versions, and setting the correct sdkVersion
in app.json
. See the versioning guide for up-to-date information about package version compatibility.
If Yarn was installed when the project was initialized, then dependencies will have been installed via Yarn, and you should probably use it to run these commands as well. Unlike dependency installation, command running syntax is identical for Yarn and NPM at the time of this writing.
Runs your app in development mode.
Open it in the Expo app on your phone to view it. It will reload if you save edits to your files, and you will see build errors and logs in the terminal.
Sometimes you may need to reset or clear the React Native packager's cache. To do so, you can pass the --reset-cache
flag to the start script:
npm start -- --reset-cache
# or
yarn start -- --reset-cache
Runs the jest test runner on your tests.
Like npm start
, but also attempts to open your app in the iOS Simulator if you're on a Mac and have it installed.
Like npm start
, but also attempts to open your app on a connected Android device or emulator. Requires an installation of Android build tools (see React Native docs for detailed setup). We also recommend installing Genymotion as your Android emulator. Once you've finished setting up the native build environment, there are two options for making the right copy of adb
available to Create React Native App:
- Make sure that you can run adb from your terminal.
- Open Genymotion and navigate to
Settings -> ADB
. Select “Use custom Android SDK tools” and update with your Android SDK directory.
- Find Genymotion’s copy of adb. On macOS for example, this is normally
/Applications/Genymotion.app/Contents/MacOS/tools/
. - Add the Genymotion tools directory to your path (instructions for Mac, Linux, and Windows).
- Make sure that you can run adb from your terminal.
This will start the process of "ejecting" from Create React Native App's build scripts. You'll be asked a couple of questions about how you'd like to build your project.
Warning: Running eject is a permanent action (aside from whatever version control system you use). An ejected app will require you to have an Xcode and/or Android Studio environment set up.
You can edit app.json
to include configuration keys under the expo
key.
To change your app's display name, set the expo.name
key in app.json
to an appropriate string.
To set an app icon, set the expo.icon
key in app.json
to be either a local path or a URL. It's recommended that you use a 512x512 png file with transparency.
This project is set up to use jest for tests. You can configure whatever testing strategy you like, but jest works out of the box. Create test files in directories called __tests__
or with the .test
extension to have the files loaded by jest. See the the template project for an example test. The jest documentation is also a wonderful resource, as is the React Native testing tutorial.
You can configure some of Create React Native App's behavior using environment variables.
When starting your project, you'll see something like this for your project URL:
exp://192.168.0.2:19000
The "manifest" at that URL tells the Expo app how to retrieve and load your app's JavaScript bundle, so even if you load it in the app via a URL like exp://localhost:19000
, the Expo client app will still try to retrieve your app at the IP address that the start script provides.
In some cases, this is less than ideal. This might be the case if you need to run your project inside of a virtual machine and you have to access the packager via a different IP address than the one which prints by default. In order to override the IP address or hostname that is detected by Create React Native App, you can specify your own hostname via the REACT_NATIVE_PACKAGER_HOSTNAME
environment variable:
Mac and Linux:
REACT_NATIVE_PACKAGER_HOSTNAME='my-custom-ip-address-or-hostname' npm start
Windows:
set REACT_NATIVE_PACKAGER_HOSTNAME='my-custom-ip-address-or-hostname'
npm start
The above example would cause the development server to listen on exp://my-custom-ip-address-or-hostname:19000
.
Flow is a static type checker that helps you write code with fewer bugs. Check out this introduction to using static types in JavaScript if you are new to this concept.
React Native works with Flow out of the box, as long as your Flow version matches the one used in the version of React Native.
To add a local dependency to the correct Flow version to a Create React Native App project, follow these steps:
- Find the Flow
[version]
at the bottom of the included .flowconfig - Run
npm install --save-dev flow-bin@x.y.z
(oryarn add --dev flow-bin@x.y.z
), wherex.y.z
is the .flowconfig version number. - Add
"flow": "flow"
to thescripts
section of yourpackage.json
. - Add
// @flow
to any files you want to type check (for example, toApp.js
).
Now you can run npm run flow
(or yarn flow
) to check the files for type errors. You can optionally use a plugin for your IDE or editor for a better integrated experience.
To learn more about Flow, check out its documentation.
Create React Native App does a lot of work to make app setup and development simple and straightforward, but it's very difficult to do the same for deploying to Apple's App Store or Google's Play Store without relying on a hosted service.
Expo provides free hosting for the JS-only apps created by CRNA, allowing you to share your app through the Expo client app. This requires registration for an Expo account.
Install the exp
command-line tool, and run the publish command:
$ npm i -g exp
$ exp publish
You can also use a service like Expo's standalone builds if you want to get an IPA/APK for distribution without having to build the native code yourself.
If you want to build and deploy your app yourself, you'll need to eject from CRNA and use Xcode and Android Studio.
This is usually as simple as running npm run eject
in your project, which will walk you through the process. Make sure to install react-native-cli
and follow the native code getting started guide for React Native.
If you have made use of Expo APIs while working on your project, then those API calls will stop working if you eject to a regular React Native project. If you want to continue using those APIs, you can eject to "React Native + ExpoKit" which will still allow you to build your own native code and continue using the Expo APIs. See the ejecting guide for more details about this option.
If you're unable to load your app on your phone due to a network timeout or a refused connection, a good first step is to verify that your phone and computer are on the same network and that they can reach each other. Create React Native App needs access to ports 19000 and 19001 so ensure that your network and firewall settings allow access from your device to your computer on both of these ports.
Try opening a web browser on your phone and opening the URL that the packager script prints, replacing exp://
with http://
. So, for example, if underneath the QR code in your terminal you see:
exp://192.168.0.1:19000
Try opening Safari or Chrome on your phone and loading
http://192.168.0.1:19000
and
http://192.168.0.1:19001
If this works, but you're still unable to load your app by scanning the QR code, please open an issue on the Create React Native App repository with details about these steps and any other error messages you may have received.
If you're not able to load the http
URL in your phone's web browser, try using the tethering/mobile hotspot feature on your phone (beware of data usage, though), connecting your computer to that WiFi network, and restarting the packager.
If you're on a Mac, there are a few errors that users sometimes see when attempting to npm run ios
:
- "non-zero exit code: 107"
- "You may need to install Xcode" but it is already installed
- and others
There are a few steps you may want to take to troubleshoot these kinds of errors:
- Make sure Xcode is installed and open it to accept the license agreement if it prompts you. You can install it from the Mac App Store.
- Open Xcode's Preferences, the Locations tab, and make sure that the
Command Line Tools
menu option is set to something. Sometimes when the CLI tools are first installed by Homebrew this option is left blank, which can prevent Apple utilities from finding the simulator. Make sure to re-runnpm/yarn run ios
after doing so. - If that doesn't work, open the Simulator, and under the app menu select
Reset Contents and Settings...
. After that has finished, quit the Simulator, and re-runnpm/yarn run ios
.
If you're not able to scan the QR code, make sure your phone's camera is focusing correctly, and also make sure that the contrast on the two colors in your terminal is high enough. For example, WebStorm's default themes may not have enough contrast for terminal QR codes to be scannable with the system barcode scanners that the Expo app uses.
If this causes problems for you, you may want to try changing your terminal's color theme to have more contrast, or running Create React Native App from a different terminal. You can also manually enter the URL printed by the packager script in the Expo app's search bar to load it manually.