HTML5 APIs You Didn't Know Existed

HTML5 APIs You Didn't Know Existed Element.classList

// Add a class to an element
myElement.classList.add("newClass");

// Remove a class to an element
myElement.classList.remove("existingClass");

// Check for existence
myElement.classList.contains("oneClass");

// Toggle a class
myElement.classList.toggle("anotherClass");

ContextMenu API The new ContextMenu API is excellent: instead of overriding the browser context menu, the new ContextMenu API allows you to simply add items to the browser's context menu:

Element.dataset The dataset API allows developers to get and set data- attribute values

/*  Assuming element:

  


*/

// Get the element
var element = document.getElementById("myDiv");

// Get the id
var id = element.dataset.id;

// Retrieves "data-my-custom-key"
var customKey = element.dataset.myCustomKey;

// Sets the value to something else
element.dataset.myCustomKey = "Some other value";

  // Element becomes:
  //