how to perform login with complete validation using Rest Api in React native

React Native provides the Fetch API for your networking needs. Fetch will seem familiar if you have used XMLHttpRequest or other networking APIs before. You may refer to MDN's guide on Using Fetch for additional information.

Making requests

In order to fetch content from an arbitrary URL, just pass the URL to fetch:

fetch('https://mywebsite.com/mydata.json');

example.js

// Example POST method implementation:

postData('http://example.com/answer', {answer: 42})
  .then(data => console.log(JSON.stringify(data))) // JSON-string from `response.json()` call
  .catch(error => console.error(error));

function postData(url = '', data = {}) {
  // Default options are marked with *
    return fetch(url, {
        method: 'POST', // *GET, POST, PUT, DELETE, etc.
        mode: 'cors', // no-cors, cors, *same-origin
        cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
        credentials: 'same-origin', // include, *same-origin, omit
        headers: {
            'Content-Type': 'application/json',
            // 'Content-Type': 'application/x-www-form-urlencoded',
        },
        redirect: 'follow', // manual, *follow, error
        referrer: 'no-referrer', // no-referrer, *client
        body: JSON.stringify(data), // body data type must match "Content-Type" header
    })
    .then(res => res.json())
.then(response => console.log('Success:', JSON.stringify(response)))
.catch(error => console.error('Error:', error));
}