{"json_modified": "2016-03-28T08:31:41.545069", "uuid": "2c1785f3-decc-4841-ba4d-6ec694b1f89e", "title": "event/core", "url": "/en-US/docs/Mozilla/Add-ons/SDK/Low-Level_APIs/event_core", "tags": [], "translations": [], "modified": "2016-01-15T10:10:40", "label": "event/core", "localization_tags": [], "locale": "en-US", "id": 87019, "last_edit": "2016-01-15T10:10:39", "summary": "The <code>event/core</code> module allows the creation of APIs to broadcast and subscribe to events.", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Usage", "title": "Usage"}, {"id": "Globals", "title": "Globals"}, {"id": "Functions", "title": "Functions"}, {"id": "on(target_type_listener)", "title": null}, {"id": "Parameters", "title": "Parameters"}, {"id": "once(target_type_listener)", "title": null}, {"id": "Parameters_2", "title": "Parameters"}, {"id": "emit(target_type_message_arguments)", "title": null}, {"id": "Parameters_3", "title": "Parameters"}, {"id": "off(target_type_listener)", "title": null}, {"id": "Parameters_4", "title": "Parameters"}, {"id": "count()", "title": null}, {"id": "Returns", "title": "Returns"}], "slug": "Mozilla/Add-ons/SDK/Low-Level_APIs/event_core", "review_tags": []}