runtime.onPerformanceWarning

Syntax

browser.runtime.onPerformanceWarning.addListener(listener)
browser.runtime.onPerformanceWarning.removeListener(listener)
browser.runtime.onPerformanceWarning.hasListener(listener)

Events have three functions:

addListener(listener)

Adds a listener to this event.

removeListener(listener)

Stop listening to this event. The listener argument is the listener to remove.

hasListener(listener)

Checks whether at least one listener is registered for this event. Returns true if it is listening, false otherwise.

addListener syntax

Parameters

listener

The function called when this event occurs. The function is passed this argument:

details

object. An object with the following properties:

category

runtime.OnPerformanceWarningCategory. The category of the warning.

severity

runtime.OnPerformanceWarningSeverity. The severity of the warning.

tabId Optional

integer. The ID of the tab that the performance warning relates to, if any.

description

string. An explanation of what the warning means, possibly with information on how to address it.

Examples

function handlePerformanceWarning(details) {
  console.log(`Performance warning: ${details.description}`);
}

browser.runtime.onPerformanceWarning.addListener(handlePerformanceWarning);

Browser compatibility