Alerts about disruptions to council services which appear across sections of www.eastsussex.gov.uk or the entire site.
Alerts are created as pages in Umbraco using the Alert document type. They are aggregated under a page using the Alerts document type, which is a list view document type. This allows permissions to be restricted for that part of the content tree.
The Alerts document type uses AlertsController to load the data, and ~\Views\Alerts.cshtml to return JSON data for all alerts. This includes an alert for school closures, which is read from an XML file in Azure storage using code from Escc.ServiceClosures.
The JSON data is consumed by alerts.js which is loaded on all sitewide master pages and MVC layouts from the Scripts*.ascx files in the Escc.EastSussexGovUK project. alerts.js also lives in Escc.EastSussexGovUK.
There are 5 minutes caches and intervals in place at various points in the school closure alerts process:
- school closures data gets sent to www.eastsussex.gov.uk every 5 minutes
- the temporary API for school closures on www.eastsussex.gov.uk requested by this app is output cached for 5 minutes
- the result of that request is held in the application cache for 5 minutes
- the
alerts.cshtmlview specifies a 5 minute HTTP cache
In the worst case it could take 20 minutes to display a school closure, but more typically these 5 minute intervals will overlap.
Alerts created in Umbraco are read from the Umbraco cache and are subject to the 5 minute HTTP cache on the alerts.cshtml view.