ReportingObserver

The ReportingObserver interface of the Reporting API allows you to collect and access reports.

ReportingObserver()

Creates a new ReportingObserver object instance, which can be used to collect and access reports.

This interface has no properties defined on it.

ReportingObserver.disconnect()

Stops a reporting observer that had previously started observing from collecting reports.

ReportingObserver.observe()

Instructs a reporting observer to start collecting reports in its report queue.

ReportingObserver.takeRecords()

Returns the current list of reports contained in the observer's report queue, and empties the queue.

This interface has no events that fire on it.

In our deprecation_report.html example, we create a simple reporting observer to observe usage of deprecated features on our web page:

let options = {
  types: ['deprecation'],
  buffered: true
}

let observer = new ReportingObserver(function(reports, observer) {
  reportBtn.onclick = () => displayReports(reports);
}, options);

We then tell it to start observing reports using ReportingObserver.observe(); this tells the observer to start collecting reports in its report queue, and runs the callback function specified inside the constructor:

observer.observe();

Later on in the example we deliberately use the deprecated version of MediaDevices.getUserMedia():

if(navigator.mozGetUserMedia) {
  navigator.mozGetUserMedia(
    constraints,
    success,
    failure);
} else {
  navigator.getUserMedia(
    constraints,
    success,
    failure);
}

This causes a deprecation report to be generated; because of the event handler we set up inside the ReportingObserver() constructor, we can now click the button to display the report details.

• Reporting API