How to execute a function 1 time?

Question

React

How to execute a function once?

class App extends React.Component {
  constructor(props) {
    super(props);

    this.state = {
      activeView: 'selectcountryandcity',
      fetchedUser: null,
    };
  }
  componentDidMount() {
  }

  checkUserBd = (userId) => {
    axios.get('http://localhost:8000/api/profiles/', {
      params: {
        vk_id:userId
      }
    })
    .then(function(response){
      if(response.data.length !== 0){
        this.setState({user: response.data[0]});
        console.log('user')
      } else {
        console.log('net')
      }
    }.bind(this))
  }
  render() {
    this.checkUserBd(123123);
         <Root activeView={this.state.activeView}>
          <SelectCountryAndCity 
            id="selectcountryandcity"
            token={this.state.token}
            countries={this.state.countries}
            cities={this.state.cities}
          />
        </Root>
  };
};

Now the CheckUserBd function starts calling an infinite number of times when loading the page, if I remove .bind (this) in the function, then the context is not transferred and the this.setState function is not visible.

Answer 1

Never write code/functions in render that change the setState state, because almost every setState is followed by render, and render will call setState again, and that one will render again - and so on forever, which is what happens to you. You can call checkUserBd inside componentDidMount.