An effect (enumerated in */attributes/effect and human-readable in */attributes/service_effect) on a provided service (facility, route, route type, stop and/or trip in /*/attributes/informed_entity) described by a banner (*/attributes/banner), short header (*/attributes/short_header), header */attributes/header, description (*/attributes/description), image (*/attributes/image), and image alternative text (*/attributes/image_alternative_text) that is active for one or more periods(*/attributes/active_period) caused by a cause (*/attribute/cause) that somewhere in its lifecycle (enumerated in */attributes/lifecycle and human-readable in */attributes/timeframe). See GTFS Realtime FeedMessage FeedEntity Alert ## Descriptions There are 7 descriptive attributes. | JSON pointer | Usage | |---------------------------------------------|---------------------------------------------------------------------------------| | */attributes/banner | Display as alert across application/website | | */attributes/short_header | When */attributes/header is too long to display | | */attributes/header | Used before showing and prepended to */attributes/description | | */attributes/description | Used when user asks to expand alert. | | */attributes/image | URL to descriptive image. | | */attributes/image_alternative_text | Text that describes image linked in url | ## Effect | JSON pointer | | |-----------------------------------------------|----------------| | */attributes/effect | Enumerated | | */attributes/service_effect | Human-readable | ## Timeline There are 3 timeline related attributes | JSON pointer | Description | |----------------------------------------------|------------------------------------------------------------------------------------------| | */attributes/active_period | Exact Date/Time ranges alert is active | | */attributes/lifecycle | Enumerated, machine-readable description of */attributes/active_period | | */attributes/timeframe | Human-readable description of */attributes/active_period |