ContentIndex: add() method

The add() method of the ContentIndex interface registers an item with the content index.

Syntax

add(contentDescription)

Parameters

contentDescription

An Object containing the following data:

id

A unique String identifier.

title

A String title for the item. Used in user-visible lists of content.

description

A String description of the item. Used in user-visible lists of content.

url

A String containing the URL of the corresponding HTML document. Needs to be under the scope of the current service worker.

category Optional

A String defining the category of content. Can be:

• '' An empty String, this is the default.
• homepage
• article
• video
• audio

icons Optional

An Array of image resources, defined as an Object with the following data:

src

A URL String of the source image.

sizes Optional

A String representation of the image size.

type Optional

The MIME type of the image.

label Optional

A string representing the accessible name of the icon.

Return value

Returns a Promise that resolves with undefined.

Exceptions

TypeError

This exception is thrown in the following conditions:

• The service worker's registration is not present or the service worker does not contain a FetchEvent.
• One of id, title, description or url parameter are missing, not of type String, or an empty String.
• The url parameter is not same-origin policy with the service worker.
• One of the items in icons are not an image type, or fetching one of the items in icons failed with a network error or decode error.

Examples

Here we're declaring an item in the correct format and creating an asynchronous function which uses the add method to register it with the content index.

// our content
const item = {
  id: "post-1",
  url: "/posts/amet.html",
  title: "Amet consectetur adipisicing",
  description:
    "Repellat et quia iste possimus ducimus aliquid a aut eaque nostrum.",
  icons: [
    {
      src: "/media/dark.png",
      sizes: "128x128",
      type: "image/png",
    },
  ],
  category: "article",
};

// our asynchronous function to add indexed content
async function registerContent(data) {
  const registration = await navigator.serviceWorker.ready;

  // feature detect Content Index
  if (!registration.index) {
    return;
  }

  // register content
  try {
    await registration.index.add(data);
  } catch (e) {
    console.log("Failed to register content: ", e.message);
  }
}

The add method can also be used within the service worker scope.

// our content
const item = {
  id: "post-1",
  url: "/posts/amet.html",
  title: "Amet consectetur adipisicing",
  description:
    "Repellat et quia iste possimus ducimus aliquid a aut eaque nostrum.",
  icons: [
    {
      src: "/media/dark.png",
      sizes: "128x128",
      type: "image/png",
    },
  ],
  category: "article",
};

self.registration.index.add(item);

Specifications

Browser compatibility

See also

• An introductory article on the Content Index API
• Service Worker API, along with information about Cache and CacheStorage