Selectors

Selectors are convenience functions that return useful data from manifest objects. The selector functions are:

• selectEditsAndActivity - Returns a formatted list of manifest edits and activity.
• selectProducer - Returns information on the producer of an asset.
• selectSocialAccounts - Returns social accounts associated with the producer of a manifest, if available.

For instance, you can use selectProducer to get information on the producer of an asset as follows:

import { selectProducer } from 'c2pa';

const producer = selectProducer(manifest);

Without using a selector, finding this information requires locating the stds.schema-org.CreativeWork assertion and having familiarity with its structure. As you can see, the code is much more complicated:

function selectProducer(manifest) {
  const cwAssertion = manifest.assertions.get('stds.schema-org.CreativeWork');
  return assertion.author?.find((x) => !x.hasOwnProperty('@id'));
}

Some selectors may involve complex, possibly asynchronous operations. For example, selectEditsAndActivity abstracts a complex operation involving multiple manifest assertions and remote resources to return a formatted list of edits and activity described within a manifest:

import { selectEditsAndActivity } from 'c2pa';

const editsAndActivity = await selectEditsAndActivity(manifest);

The result is an editsAndActivity object such as this:

[
  {
    id: 'COLOR_ADJUSTMENTS',
    icon: 'https://cai-assertions.adobe.com/icons/color-palette-dark.svg',
    label: 'Color adjustments',
    description: 'Changed tone, saturation, etc.'
  },
  {
    id: 'IMPORT',
    icon: 'https://cai-assertions.adobe.com/icons/import-dark.svg',
    label: 'Imported assets',
    description: 'Added images, videos, etc.'
  },
  {
    id: 'TRANSFORM',
    icon: 'https://cai-assertions.adobe.com/icons/group-dark.svg',
    label: 'Size and position adjustments',
    description: 'Changed size, orientation, direction, or position'
  }
]