JavaScript fetch()

JS:


const button = document.querySelector('.js-button');

const output = document.querySelector('.js-output');



async function getRandomPost() {

  try {

    const response = await fetch('https://jsonplaceholder.typicode.com/posts');

    const posts = await response.json();

    const randomIndex = Math.floor(Math.random() * posts.length);

    const randomPost = posts[randomIndex];

    output.textContent = randomPost.body;

  } catch (error) {

    console.error('Error fetching data:', error);

  }

}



document.addEventListener("DOMContentLoaded", async function() {

  await getRandomPost();

});



button.addEventListener('click', async function() {

  await getRandomPost();

});

html:


<button class="js-button">Get random post</button>

<div class="js-output"></div>

Fetch params:


const fetchData = (url, userOptions = {}) => {

    const defaultOptions = {

        method: 'POST',

        credentials: 'same-origin',

        cache: 'no-cache',

        headers: {

            'Content-Type': 'application/json',

            'LoginToken': 'l0g1n-t0k3n'

        }

    };

    // const options = jQuery.extend(defaultOptions, userOptions);

    const options = Object.assign({}, defaultOptions, userOptions);

    return fetch(url, options);

};



// Usage

fetchData(url)

    .then(response => response.json())

    .then(response => {

        console.log(response);

    })

    .catch(error => console.error('Error: ', error));



fetchData(url, {method: 'GET'})

    .then((response) => {

        return response.text();

    })

    .then(response => {

        let $responseContent = $(response).find('.content').html();

        $('.content').html($responseContent);

    })

    .catch(error => console.error('Error: ', error));

All fetch() parameters:


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; charset=utf-8",

            // "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

    })

Leave a Comment