Use ReactNative to the ios native project，and the compilation was several times slower

[luangaolei]

• [√] Review the documentation: https://facebook.github.io/react-native
• [√] Search for existing issues: https://github.com/facebook/react-native/issues
• [√] Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

React Native Environment Info:
System:
OS: macOS High Sierra 10.13.4
CPU: x64 Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz
Memory: 240.03 MB / 8.00 GB
Shell: 5.3 - /bin/zsh
Binaries:
Node: 10.8.0 - /usr/local/bin/node
Yarn: 1.9.4 - /usr/local/bin/yarn
npm: 6.2.0 - /usr/local/bin/npm
Watchman: 4.9.0 - /usr/local/bin/watchman
SDKs:
iOS SDK:
Platforms: iOS 11.4, macOS 10.13, tvOS 11.4, watchOS 4.3
IDEs:
Xcode: 9.4.1/9F2000 - /usr/bin/xcodebuild
npmPackages:
react: 16.3.1 => 16.3.1
react-native: ^0.56.0 => 0.56.0

Description

Hi，why did I add ReactNative to the native ios project? Every time when I first compiled the project, it was very slow. It was much slower than the native project.How should this problem be solved?
I tried using the latest version ReactNative v0.56.0 just now, but it still took me a long time to build the project for the first time, so the latest version doesn't solve that problem.
I find that comment out RCTWebSocket and RCTAnimation , and then pod install will not have that particularly slow compilation problem.

pod 'React', :path => '../node_modules/react-native', :subspecs => [
    'Core',
    'CxxBridge', # Include this for RN >= 0.47
    'DevSupport', # Include this to enable In-App Devmenu if RN >= 0.43
    'RCTText',
    'RCTLinkingIOS',
    'RCTPushNotification',
    'RCTImage',
    'RCTNetwork',
    #'RCTWebSocket', # Needed for debugging
    #'RCTAnimation', # Needed for FlatList and animations running on native UI thread
  ]

#21004

[mwskwong]

In short, you cannot solve it. What it does is compiling a bunch of extra objective-c, swift code from react native components into native code, so it is expected to be longer than native iOS.

However, once it is compiled and run, you can always use the "reload" feature which allows you to apply changes much faster.

To do that, press cmd + R in simulator, or shake the real device and select "reload" from the menu

[luangaolei]

@matthewkwong2 Thank you. But I'm talking about the long build time after the clean project. Or I want to archive, which is very long...

[react-native-bot]

It looks like you are using an older version of React Native. Please update to the latest release, v0.57 and verify if the issue still exists.

The ":rewind:Old Version" label will be removed automatically once you edit your original post with the results of running react-native info on a project using the latest release.

[react-native-bot]

I am closing this issue because it does not appear to have been verified on the latest release, and there has been no followup in a while.

If you found this thread after encountering the same issue in the latest release, please feel free to create a new issue with up-to-date information by clicking here.