runtime.onPerformanceWarning

This event fires when a runtime performance issue is detected for the extension. Observe this event to be notified of runtime performance problems with your extension.

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

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