Answers for "fetch react"

js fetch 'post' json

//Obj of data to send in future like a dummyDb
const data = { username: 'example' };

//POST request with body equal on data in JSON format
fetch('https://example.com/profile', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(data),
})
.then((response) => response.json())
//Then with the data from the response in JSON...
.then((data) => {
  console.log('Success:', data);
})
//Then with the error genereted...
.catch((error) => {
  console.error('Error:', error);
});

//																		Yeah

Add no cores to fetch

// There were no quick access to mode and credentials to other fetch answers.
// Data you'll be sending
const data = { funny: "Absolutely not", educational: "yas" }

fetch('https://example.com/api/', {
  method: 'POST', // The method
  mode: 'no-cors', // It can be no-cors, cors, same-origin
  credentials: 'same-origin', // It can be include, same-origin, omit
  headers: {
    'Content-Type': 'application/json', // Your headers
  },
  body: JSON.stringify(data),
}).then(returnedData => {
  // Do whatever with returnedData
}).catch(err => {
  // In case it errors.
})

react fetch

componentDidMount() {
    // GET request using fetch with error handling
    fetch('https://api.npms.io/v2/invalid-url')
        .then(async response => {
            const data = await response.json();

            // check for error response
            if (!response.ok) {
                // get error message from body or default to response statusText
                const error = (data && data.message) || response.statusText;
                return Promise.reject(error);
            }

            this.setState({ totalReactPackages: data.total })
        })
        .catch(error => {
            this.setState({ errorMessage: error.toString() });
            console.error('There was an error!', error);
        });
}

using componentdidmount with fetch

Component with Data
class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      items: [],
      isLoaded: false,
    };
  }

  componentDidMount() {
    fetch('https://jsonplaceholder.typicode.com/posts')
      .then(res => res.json())
      .then(result => {
        this.setState({
          isLoaded: true,
          items: result
        });
      });
  }

  render() {
    const { items } = this.state;
    if (!isLoaded) {
      return <div>Loading ... </div>;
    } else {
      return (
        <ul>
          {items.map(item => (
            <li key={item.id}>
              <h3>{item.title}</h3>
              <p>{item.body}</p>
            </li>
          ))}
        </ul>
      );
    }
  }
}
Fetching Data - Ha

React get method

/* React get method.  */

componentWillMount(){
    fetch('/getcurrencylist',
    {
        /*
        headers: {
          'Content-Type': 'application/json',
          'Accept':'application/json'
        },
        */
        method: "get",
        dataType: 'json',
    })
    .then((res) => res.json())
    .then((data) => {
      var currencyList = [];
      for(var i=0; i< data.length; i++){
        var currency = data[i];
        currencyList.push(currency);
      }
      console.log(currencyList);
      this.setState({currencyList})
      console.log(this.state.currencyList);
    })
    .catch(err => console.log(err))
  }

fetch

var formData = new FormData();
var fileField = document.querySelector("input[type='file']");

formData.append('username', 'abc123');
formData.append('avatar', fileField.files[0]);

fetch('https://example.com/profile/avatar', {
  method: 'PUT',
  body: formData
})
.then(response => response.json())
.catch(error => console.error('Error:', error))
.then(response => console.log('Success:', response));