javascript - Can you add an external function as a method in a React component class? - Stack Overflow

Given the following React ponent:class MyComponent extends Component {sayGreeting = () => {return th

Given the following React ponent:

class MyComponent extends Component {
  sayGreeting = () => {
    return this.props.greeting;
  }

  render() {
    return (
      <div>{this.sayGreeting()}</div>
    );
  }
}

greeting is passed via props and is just a string message. Given sayGreeting() might be used in multiple ponents, with the exact same definition, would it be possible to extract it into a file (see the following code) and then somehow include it in each ponent as needed. This is like the include module (or mixin?) pattern in programming languages like Ruby.

export const sayGreeting = () => {
  return this.props.greeting;
};

I was able to do it by importing sayGreeting from that file and setting the prototype of MyComponent as such:

import { sayGreeting } from './someFile';
// ...
MyComponent.prototype.sayGreeting = sayGreeting; 

But the issue is the "this" keyword, so props will not be defined. I tried binding in the constructor using this.sayGreeting = this.sayGreeting.bind(this), but it didn't work.

Given the following React ponent:

class MyComponent extends Component {
  sayGreeting = () => {
    return this.props.greeting;
  }

  render() {
    return (
      <div>{this.sayGreeting()}</div>
    );
  }
}

greeting is passed via props and is just a string message. Given sayGreeting() might be used in multiple ponents, with the exact same definition, would it be possible to extract it into a file (see the following code) and then somehow include it in each ponent as needed. This is like the include module (or mixin?) pattern in programming languages like Ruby.

export const sayGreeting = () => {
  return this.props.greeting;
};

I was able to do it by importing sayGreeting from that file and setting the prototype of MyComponent as such:

import { sayGreeting } from './someFile';
// ...
MyComponent.prototype.sayGreeting = sayGreeting; 

But the issue is the "this" keyword, so props will not be defined. I tried binding in the constructor using this.sayGreeting = this.sayGreeting.bind(this), but it didn't work.

Share Improve this question asked Feb 15, 2017 at 2:32 nbkhopenbkhope 7,4844 gold badges43 silver badges59 bronze badges 1
  • You could always pass props, like <div>{this.sayGreeting(props)}</div> – Jordan Bonitatis Commented Feb 15, 2017 at 3:45
Add a ment  | 

2 Answers 2

Reset to default 2

You can use a higher-order ponent:

const myHOC = (posedComponent) => { 
  return class extends React.Component {
    sayGreeting = () => {
      return this.props.greeting;
    }

    render() {
      return <ComposedComponent sayGreeting={ this.sayGreeting } />;
    }
  };
};

class MyComponent extends React.Component {
   render() {
      return <div>{this.props.sayGreeting()}</div>
   }
}

export default MyHOC(MyComponent);

Pass this into the function.

export const sayGreeting = ({props}) => {
  return props.greeting;
};

Then to use after importing: sayGreeting(this)

发布者:admin,转转请注明出处:http://www.yc00.com/questions/1745627911a4636922.html

相关推荐

发表回复

评论列表(0条)

  • 暂无评论

联系我们

400-800-8888

在线咨询: QQ交谈

邮件:admin@example.com

工作时间:周一至周五,9:30-18:30,节假日休息

关注微信