Types

FDC3 API operations make use of several type declarations.

Context

interface Context {
  id?: { [key: string]: string };
  name?: string;
  type: string;
}

The base interface that all contexts should extend: a context data object adhering to the Context Data Specification.

This means that it must at least have a type property that indicates what type of data it represents, e.g. 'fdc3.contact'. The type property of context objects is important for certain FDC3 operations, like Channel.getCurrentContext and DesktopAgent.addContextListener, which allows you to filter contexts by their type.

See also

• ContextHandler
• DesktopAgent.open
• DesktopAgent.broadcast
• DesktopAgent.addIntentListener
• DesktopAgent.addContextListener
• DesktopAgent.findIntent
• DesktopAgent.findIntentsByContext
• DesktopAgent.raiseIntent
• DesktopAgent.raiseIntentForContext
• Channel.broadcast
• Channel.getCurrentContext
• Channel.addContextListener

ContextHandler

type ContextHandler = (context: Context) => void;

Describes a callback that handles a context event.

Used when attaching listeners for context broadcasts and raised intents.

See also

• Context
• DesktopAgent.addIntentListener
• DesktopAgent.addContextListener
• Channel.addContextListener

Listener

A Listener object is returned when an application subscribes to intents or context broadcasts via the addIntentListener or addContextListener methods on the DesktopAgent object.

interface Listener {
  unsubscribe(): void;
}

unsubscribe

unsubscribe(): void;

Allows an application to unsubscribe from listening to intents or context broadcasts.

See also

• DesktopAgent.addIntentListener
• DesktopAgent.addContextListener
• Channel.addContextListener
• ContextHandler

TargetApp

type TargetApp = string | AppMetadata;

Operations that target apps (like open or raiseIntent) can identify an app just by by its name, or pass full app metadata, giving the desktop agent more information about the targeted app.

See also

• AppMetadata
• DesktopAgent.open
• DesktopAgent.raiseIntent
• DesktopAgent.raiseIntentForContext
• IntentResolution

Icon

interface Icon {
  src: string;
  size?: string;
  type?: string;
}

AppMetadata includes an icons property allowing multiple icon types to be specified. Various properties may be used by the Desktop Agent to decide which icon is the most suitable to be used considering the application chooser UI, device DPI and formats supported by the system.

Example

"icons": [
  {
    "src": "https://app.foo.icon/app_icons/lowres.webp",
    "size": "48x48",
    "type": "image/webp"
  },
  {
    "src": "https://app.foo.icon/app_icons/hd_hi.svg",
    "size": "72x72",
    "type": "image/svg+xml"
  }
]

Properties

src

The fully qualified url to the icon.

size

The dimension of the icon using formatted as "x"

type

The media type of the icon. If not provided the Desktop agent may refer to the src file extension.

See also

• AppMetadata