{"json_modified": "2016-09-17T14:28:58.583240", "uuid": "eabc0eed-190c-42c6-a312-e5515b779f03", "title": "tabs.onActiveChanged", "url": "/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/onActiveChanged", "tags": ["API", "onActiveChanged", "tabs", "Reference", "Event", "Non-standard", "Extensions", "Add-ons", "WebExtensions", "Deprecated", "Non-Standard", "add-ons"], "translations": [], "modified": "2016-09-17T14:28:58", "label": "tabs.onActiveChanged", "localization_tags": [], "locale": "en-US", "id": 172223, "last_edit": "2016-09-17T13:50:28", "summary": "Fires when the selected tab in a window changes. Note that the tab's URL may not be set at the time this event fired, but you can listen to <a href=\"/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/onUpdated\" title=\"Fired when a tab is updated.\"><code>tabs.onUpdated</code></a> events to be notified when a URL is set.", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Syntax", "title": "Syntax"}, {"id": "addListener_syntax", "title": "addListener syntax"}, {"id": "Parameters", "title": "Parameters"}, {"id": "Additional_objects", "title": "Additional objects"}, {"id": "selectInfo", "title": "selectInfo"}, {"id": "Browser_compatibility", "title": "Browser compatibility"}, {"id": "Examples", "title": "Examples"}], "slug": "Mozilla/Add-ons/WebExtensions/API/tabs/onActiveChanged", "review_tags": []}