CODEWITHSUNDEEP
javascriptreactjsecmascript-6babeljses6-class
Koala7
Koala7

Reputation: 1404

ECMAScript 5 - Error Missing class properties transform

I am implementing the Class extend and i get this error Missing class properties transform.

The Component was

import React from ('react')

const Manna = React.createClass({,

  initVal: {
       likes: 10,
   }

   render() {
     // code
      return {
        // code
      }

   }

});

module.exports = Manna

and changed to

import React from 'react';

export default class Manna extends React.Component {

  InitVal: {
    likes: 10
  }

  render() {
     // code
    return {
       // code
    }

  }

};

This is my configuration in webpack.config.dev.js

{
  test: /\.js$/,
  loaders: 'babel?presets[]=react,presets[]=es2015,presets[]=stage-0',
  include: path.join(__dirname, 'client')
},

I have changed the loader following this answer

Before it was loaders: ['babel']

I have also added to .babelrc the plugin

["transform-class-properties"],

This is the error in the console

 Missing class properties transform.
  15 |   // },
  16 | 
> 17 |   InitVal: {
     |   ^
  18 |     likes: 10,
  19 |     code: "2",
  20 |     size: 350,

I do not understand why it is complaining now for Missing class properties transform, what is wrong in the component?, everything was working fine before of these changes

Here a gist with the full React component

Upvotes: 1

Views: 1061

Answers (1)

Matteo Basso
Matteo Basso

Reputation: 2704

Try with =

import React from 'react';

export default class Manna extends React.Component {

  InitVal = {
    likes: 10
  }

  render() {
     // code
    return {
       // code
    }

  }

};

Check this

UPDATE

Since we are using stage-0 and transform-class-properties is included in stage-2, we don't have to include it manually in .babelrc under plugins. The following configuration works fine: "presets": ["es2015", "stage-0", "react"].

In the gist at line 5 InitVal is written with an uppercase i while at line 39 is written with a lowercase i: initVal. Additionally render method returns an Object Literal, which is invalid, a single child element as to be returned as explained here.

Here is the official documentation for react components defined as es6 classes.

Upvotes: 1

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