presence-button-web/public/client.js

// client-side js
// run by the browser each time your view template is loaded

(function(){
  console.log('hello world :o');
  
  // our default array of dreams
  const dreams = [
    'Find and count some sheep',
    'Climb a really tall mountain',
    'Wash the dishes'
  ];
  
  // define variables that reference elements on our page
  const dreamsList = document.getElementById('dreams');
  const dreamsForm = document.forms[0];
  const dreamInput = dreamsForm.elements['dream'];
  
  // a helper function that creates a list item for a given dream
  const appendNewDream = function(dream) {
    const newListItem = document.createElement('li');
    newListItem.innerHTML = dream;
    dreamsList.appendChild(newListItem);
  }
  
  // iterate through every dream and add it to our page
  dreams.forEach( function(dream) {
    appendNewDream(dream);
  });
  
  // listen for the form to be submitted and add a new dream when it is
  dreamsForm.onsubmit = function(event) {
    // stop our form submission from refreshing the page
    event.preventDefault();
    
    // get dream value and add it to the list
    dreams.push(dreamInput.value);
    appendNewDream(dreamInput.value);
  
    // reset form 
    dreamInput.value = '';
    dreamInput.focus();
  };
  
})()