Cannot read property 'string' of undefined | React.PropTypes | L

ghz 6months ago ⋅ 45 views

Cannot read property 'string' of undefined | React.PropTypes | LayoutPropTypes.js

After deleting and reinstalling my node_modules folder, I'm facing an issue that I don't understand in LayoutPropTypes.js file.

In node_modules/react-native/Libraries/StyleSheet/LayoutPropTypes.js The following variable is undefined : var ReactPropTypes = require('React').PropTypes;

react-native: 0.45.1 react: 16.0.0-alpha.12

Answers

The issue you're encountering is related to the deprecation and removal of React.PropTypes in React 16. Since React 16, PropTypes are no longer part of the main react package and have been moved to a separate prop-types package.

In React Native 0.45.1, it seems the library is still referencing React.PropTypes, which is causing the error because PropTypes is not found in React 16.

Solution

You need to update your React Native version to a more recent one that supports React 16. Alternatively, if updating React Native is not an option, you can manually patch the code to use the prop-types package.

Steps to Fix

  1. Install prop-types Package: First, ensure you have prop-types installed in your project:

    npm install prop-types

  2. Modify LayoutPropTypes.js: Open node_modules/react-native/Libraries/StyleSheet/LayoutPropTypes.js and update the import to use the prop-types package.

    // Change this line
// var ReactPropTypes = require('React').PropTypes;

// To this line
var PropTypes = require('prop-types');

  3. Update References: Update any reference to ReactPropTypes in the file to PropTypes.

    // Example:
// height: ReactPropTypes.number,

// Change to:
height: PropTypes.number,

Example Patch

Here is a sample of how you might modify LayoutPropTypes.js:

var PropTypes = require('prop-types');
var LayoutPropTypes = {
  width: PropTypes.number,
  height: PropTypes.number,
  top: PropTypes.number,
  left: PropTypes.number,
  right: PropTypes.number,
  bottom: PropTypes.number,
  // Add other prop types as needed
};

module.exports = LayoutPropTypes;

Long-Term Solution

Updating your React Native version is the recommended long-term solution. To update React Native, you can follow the official React Native upgrade guide. Typically, you would update your package.json dependencies and run npm install or yarn install.

{
  "dependencies": {
    "react": "^16.0.0",
    "react-native": "^0.63.0"
  }
}

Then, run:

npm install
# or
yarn install

After updating, make sure to test your application thoroughly, as major updates can introduce breaking changes.

#javascript