Creating React Native CLI project - react-native

I just switched to React Native from React and followed instructions on official site for creating and initialization project. I'm not using Expo, created project with npx and typescript template. When I opened project there was ruby-version and Gemfile files inside. I cannot find any documentation on website about Gemfile and why is ruby necessary in project creation, anyone got some more info or some docs that I missed on site? Thanks.

Your simple answer is for iOS Development.
Using react native we can do iOS development. So, for ios we need cocoapods, for using cocoapods we need ruby and this Gemfile over there.

Related

Using highcarts in react native and getting the error

I have installed npm install #highcharts/highcharts-react-native in my react native project and i also added the hcscript in metro.config.js file.
Iam getting the error of
Failed to fetch scripts or layout. The method or property expo-file-system.readDirectoryAsync is not available on android, are you sure you've linked all the native dependencies properly?
if you wanted to use this package: #highcharts/highcharts-react-native you should first install react-native-unimodules which is a set of native dependencies used at the core of #highcharts/highcharts-react-native as
they built the package on top of expo not bare react native.
it is going to require you to make heavy edits in the native ios and android files such as appDelegate.m in ios and more alike files.
However, you should notice this package is deprecated as per the official page, and there is no reliable alternative!

react native how to know if a repo I am importing is a native module

my question might be a little bit silly or ambiguous since I am fairly new to react native.
I'm trying to use the following repository for my react-native project https://github.com/smekalka/react-native-universal-pedometer. I have noticed that the repo is implemented in .java with platform folder unlike the regular .js or .ts files I used to see. Is this repository considered native module as react native doc describe?
Or in general how I can tell the whatever lib I am using is a native module.
The project is previously tested are under the support of expo-cli. I experienced the error null is not n object while using this repo. If so, I am probably going to eject the expo-cli and rewrite my code so I can use and even create own native-module for full control, some core implementations that written in other languages or expo-cli does not support.
Yes, the android and ios directories in the repository contain the 'native' code used to implement the platform-specific hooks that the Javascript will be able to pick up. Expo is not able to use these native modules or native code so your assumption is correct; you will need to eject your app in order to use this module.
If your app is below version 0.60 of React Native, after installing the module you will need to run react-native link react-native-universal-pedometer to link the native code to the Javascript runtime. If you're above 0.60, it will link automatically when installed.

When to use react-native link?

I understand that react-native link (see post) is an automatic way to install native dependencies. The post above explain how to use the link command but lacking the detail of when to use it. Should it be used after adding a component, every code change or after introducing new module to the app?
Why we use react-native-link??
In this post, I will explain why we use react native link command and when we need to use this command or not?
First, we will understand what is native module??
Native Modules
Native modules are usually distributed as npm packages, apart from the typical javascript files and resources they will contain an Android and ios library project. 
React Native provides an impressive amount of native modules that give you direct access to core platform APIs on both Android and IOS.
For example react-native-maps, react-native-firebase, react-native-socketio etc.
These modules or packages contained both platform (Android and Ios) code.
Now coming on to the react native link
Those libraries which are use native code, in that case you'll have to add these files to your app. For linking those library with react native code need to run react-native-link
Here are the few steps to link your libraries that contain native code
Automatic linking
Step 1
Install a library with native dependencies:
$ npm install --save
Step 2
Link your native dependencies:
$ react-native link
Done! All libraries with native dependencies should be successfully linked to your iOS/Android project.
Where we don't use react-native-link??
Those components which are only written in javascript they are not using any native code (Android and Ios). There is no need to run react-native-link.
For example rn-modal-picker, react-native-check-box etc.
You should check out this other answer: The use of react-native-link command?
You only need to run react-native link NAME_OF_PACKAGE when you install a new package that has a native codebase, or without arguments if you want to do it for multiple of them.

Init IOS project with pods using react-native init command

Is there any way to create the IOS project with pods using react-native init command?
Currently there is different installation instruction for react native libraries.
Example: Some of them install using react-native link command while other requires to setup using cocoapods. Missing both will leads to lots of compilation errors.
Could anyone suggest what is best way to create project using react-native.
Thanks
On the official react native documentation, there are 2 ways to start up your project, which is using 'CRNA' or 'Build With Native Code'.
For CRNA, it is the fastest and easiest way to start up your project.
It really easy to run your React Native app on a physical device without setting up a development environment. If you want to run your app on the iOS Simulator or an Android Virtual Device, please refer to the instructions for building projects with native code to learn how to install Xcode and set up your Android development environment.
The react native link is used if you want to link your library through the terminal. But in some cases, there are several problem occurred related to library compatibility. I rather suggest use pods or manually link your library through XCode.
Pods is a dependency manager for native code that we use on our native code project. It will automatically generate and link the library.
If you want to have pods on your ios project. After you install cocoapods, you could follow these steps :
1. Open terminal and direct to your project (cd YOUR_PROJECT/ios
2. pod init
3. And then Podfile will be generated within the ios project.
And from now on, you should use YOUR_PROJECT.xcworkspace if you want to manage the project. Thats because Pods should be placed and included same with your project but '.xcodeproj' does not include your Pods.

How to integrate react-native-video when using Podfiles to integrate react-native?

In the installation instructions for iOS, it says to run
react-native link
After completion I see:
However, compiling immediately fails with the error React/RCTViewManager.h not found:
When looking at the integration instructions on Facebook's website, it has us using a Podfile. When you use a Podfile, your project looks like this:
Comparing this to the react native sample project, I can see that in fact, it does not appear to use a Podfile to integrate react native at all; instead all React components are included as libraries:
Thus, I suspect that the integration instructions for react-native-video are not compatible with the integration instructions found here.
Can anyone suggest how to integrate react-native-video when using Podfiles to integrate react-native?
What version of react native are you using? This looks like it's due to the breaking change for RN version >0.40.
The short fix for this issue is if you see #import React/$(filename) in the native code, replace it with #import "$(filename)", but if you can update to RN >0.40 that would be preferable.
To answer your question about pods, you should be able to add something like pod 'react-native-video', :path => '../node_modules/react-native-video' to your podfile and run pod install (if the relative path from your Podfile to the library root is incorrect replace it with the correct one). Looking at the github page for react-native-video, it does have a podspec so it probably supports cocoapods installation