Re-Natal

A utility for building ClojureScript-based React Native apps

Artur Girenko @drapanjanas

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Re-Natal is a simple command-line utility that automates most of the process of setting up a React Native app running on ClojureScript with Reagent + re-frame, Om.Next or Rum.

This project is a fork of dmotz/natal by Dan Motzenbecker.

Figwheel support is based on the brilliant solution developed by Will Decker decker405/figwheel-react-native, which works on both platforms.

For more ClojureScript React Native resources visit cljsrn.org.

Contributions are very welcome.

Status

• Uses React Native v0.42.0
• Reusable codebase between iOS and Android
• Figwheel used for REPL and live coding
  • Works in iOS (real device and simulator)
  • Works in Android (real device and simulators, specifically AVD and Genymotion)
  • Figwheel REPL can be started from within nREPL
  • Simultaneous development of iOS and Android apps
  • Manual reload and automatic hot reload
  • Custom react-native components supported
  • Source maps available
• Supported React wrappers: Reagent, Om.Next, and Rum
• Unified way of using static images of React Native 0.14+ supported

Dependencies

As Re-Natal is an orchestration of many individual tools, there are quite a few dependencies. If you've previously done React Native or Clojure development, you should hopefully have most installed already. Platform dependencies are listed under their respective tools.

• npm >=1.4
  • Node.js >=4.0.0
• react-native-cli >=0.1.7 (install with npm install -g react-native-cli)
• Leiningen >=2.5.3
  • Java 8

For iOS development:

• Xcode (+ Command Line Tools) >=6.3
  • OS X >=10.10

Creating a new project

Before getting started, make sure you have the required dependencies installed.

Then, install the CLI using npm:

$ npm install -g re-natal

To generate a new app, run re-natal init with your app's name as an argument:

$ re-natal init FutureApp

This will generate a project which uses Reagent v0.5.1.
You may specify the -i option to choose a specific React wrapper: Om.Next, Reagent v0.6 or Rum:

$ re-natal init FutureApp -i [om-next | reagent6 | rum]

If your app's name is more than a single word, be sure to type it in CamelCase. A corresponding hyphenated Clojure namespace will be created.

The init process will take a few minutes — coffee break! If all goes well you should see basic instructions on how to run in iOS simulator.

Development with Figwheel

Initially the index.*.js files are generated with the production profile, ready for deployment.
However, during development it is better to use the development profile and integrate with Figwheel. Switch to the development profile with:

$ re-natal use-figwheel

This command needs to be run every time you switch to the development profile or specify a development environment (with use-ios-device or use-android-device).

NOTE: You might need to restart React Native Packager and reload your app.

Start the Figwheel REPL with

$ lein figwheel [ios | android]

If all went well you should see the REPL prompt and changes in source files should be hot-loaded by Figwheel.

Starting Figwheel REPL from nREPL

To start Figwheel from within nREPL session:

$ lein repl

Then in the nREPL prompt type:

user=> (start-figwheel "ios")

Or, for Android build type:

user=> (start-figwheel "android")

Or, for both type:

user=> (start-figwheel "ios" "android")

Running the app

Note for Linux users

On Linux, the React Native Packager has to be started manually with

react-native start

See here for more details.

iOS

Using iOS simulator

re-natal use-ios-device simulator
react-native run-ios

Using real iOS device

re-natal use-ios-device real

If this doesn't correctly detect your computer's IP you can pass your IP address explicitly: re-natal use-ios-device <IP address>.
And then run

react-native run-ios

Switching between iOS devices

Run use-ios-device to configure device type you want to use in development:

$ re-natal use-ios-device <real|simulator>
$ re-natal use-figwheel
$ lein figwheel ios

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Android

Using Android Virtual Device (AVD)

Set up a virtual device in AVD. Start the virtual device then run

$ re-natal use-android-device avd
$ re-natal use-figwheel
$ lein figwheel android
$ react-native run-android

Using Genymotion simulator

Set up and start the Genymotion simulator then run

$ re-natal use-android-device genymotion
$ re-natal use-figwheel
$ lein figwheel android
$ react-native run-android

Using real Android device

To run figwheel with real Android device please read Running on Device.
To make it work on a USB connected device I also had to run:

$ adb reverse tcp:8081 tcp:8081
$ adb reverse tcp:3449 tcp:3449

Then:

$ re-natal use-android-device real
$ re-natal use-figwheel
$ lein figwheel android
$ react-native run-android

Switching between Android devices

Run use-android-device to configure device type you want to use in development:

$ re-natal use-android-device <real|genymotion|avd>
$ re-natal use-figwheel
$ lein figwheel android

Developing iOS and Android apps simultaneously

$ re-natal use-figwheel
$ lein figwheel ios android

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Using external React Native Components

Lets say you have installed an external library from npm like this:

$ npm i some-library --save

And you want to use a component called 'some-library/Component':

(def Component (js/require "some-library/Component"))

This would work when you do lein prod-build and run your app, but will fail when you run with Figwheel. The React Native packager statically scans for all calls to require and prepares the required code to be available at runtime. But, dynamically loaded (by Figwheel) code bypasses this scan and therefore requiring the custom component fails.

To overcome this run use-component:

$ re-natal use-component some-library/Component

or for a platform-specific component use the optional platform parameter:

$ re-natal use-component some-library/ComponentIOS ios

Then, regenerate index.*.js files:

$ re-natal use-figwheel

Lastly, you will have to restart the packager and reload your app.

NOTE: If you mistyped something, or no longer use the component and would like to remove it, manually open .re-natal and fix it there (it's just a list of names in JSON format, so the process should be straight forward).

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Faster Figwheel hot reloading

Since version 0.22 React Native supports Hot Module Reload. But at least for now, this feature is redundant because we have Figwheel.

It looks like Figwheel reloads are faster if Hot Moduler Reload is OFF. Also, the packager is not necessary to watch for changed files - Figwheel does that (except on Linux).

Two things you can do:

1. Turn off HMR from the development menu.
2. Start the packager with option --nonPersistent. You can use npm start for that.

REPL

You have to reload your app, and should see the REPL coming up with the prompt.

At the REPL prompt, try loading your app's namespace:

(in-ns 'future-app.ios.core)

Changes you make via the REPL or by changing your .cljs files should appear live in the simulator.

Try this command as an example:

(dispatch [:set-greeting "Hello Native World!"])

Running on Linux

In addition to the instructions above on Linux you might need to start React Native packager manually with command react-native start. This was reported in #3

See this tutorial on how to set up and run re-natal on a clean install of Ubuntu.

See also Linux and Windows support in React Native docs.

Production build

Do this with command:

$ lein prod-build

Follow the React Native documentation to proceed with the release.

Static Images

Since version 0.14 React Native supports a unified way of referencing static images

In Re-Natal skeleton images are stored in "images" directory. Place your images there and reference them from cljs code:

(def my-img (js/require "./images/my-img.png"))

Adding an image during development

When you have dropped a new image to "images" dir, you need to restart React Native packager and re-run command:

$ re-natal use-figwheel

This is needed to regenerate index.*.js files which includes require calls to all local images. After this you can use a new image in your cljs code.

Upgrading existing Re-Natal project

Upgrading React Native version

To upgrade React Native to newer version please follow the official Upgrading guide of React Native. Re-Natal makes almost no changes to the files generated by react-native so the official guide should be valid.

Upgrading Re-Natal CLI version

Do this if you want to use newer version of re-natal.

Commit or backup your current project, so that you can restore it in case of any problem ;)

Upgrade re-natal npm package

$ npm upgrade -g re-natal

In root directory of your project run

$ re-natal upgrade

This will overwrite only some files which usually contain fixes in newer versions of re-natal, and are unlikely to be changed by the user. No checks are done, these files are just overwritten:

• files in /env directory
• figwheel-bridge.js

Then to continue development using figwheel

$ re-natal use-figwheel

Enabling source maps when debugging in chrome

To make source maps available in "Debug in Chrome" mode re-natal patches the react native packager to serve *.map files from file system and generate only index.*.map file. To achieve this this line of file "node_modules/react-native/packager/react-packager/src/Server/index.js" is modified to match only index.*.map

To do this run: re-natal enable-source-maps and restart packager.

You can undo this any time by deleting node_modules and running re-natal deps

Example Apps

• Luno is a demo mobile application written in ClojureScript.
• Re-Navigate example of using new Navigation component NavigationExperimental
• Showcase of iOS navigation with react-native-router-flux and Om.Next
• Catlantis is a funny demo application about cats
• Lymchat App to learn different cultures. Lym is available in App Store.
• Status (Github): a web3 browser, messenger, and gateway to a decentralised world of Ethereum. re-natal + re-frame + cljs + golang
• React Native TodoMVC is a mobile application which attempts to implement TodoMVC in Clojurescript and React Native.

Tips

• Having rlwrap installed is optional but highly recommended since it makes the REPL a much nicer experience with arrow keys.

• Running multiple React Native apps at once can cause problems with the React Packager so try to avoid doing so.

• You can launch your app on the simulator without opening Xcode by running react-native run-ios in your app's root directory (since RN 0.19.0).

• To change advanced settings run re-natal xcode to quickly open the Xcode project.

• If you have customized project layout and re-natal upgrade does not fit you well, then these commands might be useful for you:

  • re-natal copy-figwheel-bridge - just copies figwheel-bridge.js from current re-natal

Local Development of Re-Natal

If you would like to run any of this on your local environment first clone the code to an appropriate place on your machine and install dependencies

$ git clone https://github.com/drapanjanas/re-natal.git
$ cd re-natal
$ npm install

To test any changes made to re-natal, cd to an already existing project or a brand new dummy project:

$ cd ../already-existing

and run the re-natal command line like so

$ node ../re-natal/index.js

  Usage: re-natal [options] [command]


  Commands:

    init [options] <name>      create a new ClojureScript React Native project
    upgrade                    upgrades project files to current installed version of re-natal (the upgrade of re-natal itself is done via npm)
    xcode                      open Xcode project
    deps                       install all dependencies for the project
    use-figwheel               generate index.ios.js and index.android.js for development with figwheel
    use-android-device <type>  sets up the host for android device type: 'real' - localhost, 'avd' - 10.0.2.2, 'genymotion' - 10.0.3.2
    use-ios-device <type>      sets up the host for ios device type: 'simulator' - localhost, 'real' - auto detect IP on eth0, IP
    use-component <name>       configures a custom component to work with figwheel. name is the value you pass to (js/require) function.
    enable-source-maps         patches RN packager to server *.map files from filesystem, so that chrome can download them.
    copy-figwheel-bridge       copy figwheel-bridge.js into project

  Options:

    -h, --help     output usage information
    -V, --version  output the version number

You can then run any of the commands manually.