Presentation.receiver - Web APIs 编辑

The read-only Presentation attribute receiver, which is only available in browser contexts which are receiving a presentation, returns the PresentationReceiver object which can be used to access and communicate with the browser context which controls the presentation. This property is always null when accessed from outside a browser context which is receiving a presentation.

Syntax

receiver = Presentation.receiver;

receiver = navigator.presentation.receiver;

Since the Presentation interface is typically accessed through navigation.presentation, the second form of the syntax shown above is the more commonly used.

Value

If the code is running in a context which is receiving a presentation, the returned value is a PresentationReceiver which can then be used to communicate with the context which is the source of the presentation.

If the current context is not receiving a presentation, receiver is null.

Example

Determining whether or not the context is receiving a presentation

You can easily determine whether or not the context is the receiver for a presentation by checking the value of navigator.receiver. If it's a non-null value, then the context is indeed receiving a presentation. If it's null, there's no incoming presentation.

if (navigator.receiver) {
  footer.innerHTML = "Receiving presentation";
}  else {
  footer.innerHTML = "(idle)";
}

Accessing the connection list

This example uses receiver to access the list of incoming connections and to build and display a list of those connections' ID strings.

let listElem = document.getElementById("connectionview");

navigator.presentation.receiver.connectionList
          .then(function(connections) {
    connections.forEach(function(aConnection)) {
      listElem.innerHTML += "<li>" + aConnection.id
            + "</li>";
    });
});

After getting access to the output list element in the variable connectionView, navigator.receiver is used to get a reference to the PresentationReceiver object for this context, and its connectionList is used to get a Promise which will be called when the list is available.

The promise handler receives as its input parameter an array of the incoming connections. We iterate over these using forEach(), appending a new item to the connectionView list element for each connection.

Specifications

Browser Compatibility

BCD tables only load in the browser

See also

• Presentation API
• Presentation
• PresentationReceiver