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How to call Call API in Javascript?

js api call

// Create a request variable and assign a new XMLHttpRequest object to it.
var request = new XMLHttpRequest()

// Open a new connection, using the GET request on the URL endpoint'GET', '', true)

request.onload = function () {
  // Begin accessing JSON data here

// Send request

Add a JavaScript file named site.js to the wwwroot/js folder. Replace the contents of site.js with the following code:

const uri = 'api/todoitems';
let todos = [];

function getItems() {
    .then(response => response.json())
    .then(data => _displayItems(data))
    .catch(error => console.error('Unable to get items.', error));

function addItem() {
  const addNameTextbox = document.getElementById('add-name');

  const item = {
    isComplete: false,
    name: addNameTextbox.value.trim()

  fetch(uri, {
    method: 'POST',
    headers: {
      'Accept': 'application/json',
      'Content-Type': 'application/json'
    body: JSON.stringify(item)
    .then(response => response.json())
    .then(() => {
      addNameTextbox.value = '';
    .catch(error => console.error('Unable to add item.', error));

function deleteItem(id) {
  fetch(`${uri}/${id}`, {
    method: 'DELETE'
  .then(() => getItems())
  .catch(error => console.error('Unable to delete item.', error));

function displayEditForm(id) {
  const item = todos.find(item => === id);
  document.getElementById('edit-name').value =;
  document.getElementById('edit-id').value =;
  document.getElementById('edit-isComplete').checked = item.isComplete;
  document.getElementById('editForm').style.display = 'block';

function updateItem() {
  const itemId = document.getElementById('edit-id').value;
  const item = {
    id: parseInt(itemId, 10),
    isComplete: document.getElementById('edit-isComplete').checked,
    name: document.getElementById('edit-name').value.trim()

  fetch(`${uri}/${itemId}`, {
    method: 'PUT',
    headers: {
      'Accept': 'application/json',
      'Content-Type': 'application/json'
    body: JSON.stringify(item)
  .then(() => getItems())
  .catch(error => console.error('Unable to update item.', error));


  return false;

function closeInput() {
  document.getElementById('editForm').style.display = 'none';

function _displayCount(itemCount) {
  const name = (itemCount === 1) ? 'to-do' : 'to-dos';

  document.getElementById('counter').innerText = `${itemCount} ${name}`;

function _displayItems(data) {
  const tBody = document.getElementById('todos');
  tBody.innerHTML = '';


  const button = document.createElement('button');

  data.forEach(item => {
    let isCompleteCheckbox = document.createElement('input');
    isCompleteCheckbox.type = 'checkbox';
    isCompleteCheckbox.disabled = true;
    isCompleteCheckbox.checked = item.isComplete;

    let editButton = button.cloneNode(false);
    editButton.innerText = 'Edit';
    editButton.setAttribute('onclick', `displayEditForm(${})`);

    let deleteButton = button.cloneNode(false);
    deleteButton.innerText = 'Delete';
    deleteButton.setAttribute('onclick', `deleteItem(${})`);

    let tr = tBody.insertRow();
    let td1 = tr.insertCell(0);

    let td2 = tr.insertCell(1);
    let textNode = document.createTextNode(;

    let td3 = tr.insertCell(2);

    let td4 = tr.insertCell(3);

  todos = data;


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