WebsydianExpress - Callback Point

ApplicationServiceStart

Type

Global callback point implemented by the WebsydianExpress runtime.

Note that changing the callback functions for a global callback point impacts all the sites.

When is the callback point called

ApplicationServiceStart is called when the Application service is started by the start commands/scripts.

At this point not requests has been received.

How does the callback point influence later functionality

Normally, the functionality entered in this callback point will only indirectly have an impact on the later functionality.

Errors returned in *Returned Status are disregarded by the callback point.

Example of use

The most common use of this callback point is to assign any resources that must be available for the Application Service job.

For example, if the application needs to use a backend ERP system, we have found that it often takes so long establish this connection that it is not practical to do so for each request. In most cases you would establish this connection in this callback point and close it in ApplicationServiceEnd.

You can also use it together with ApplicationServiceEnd, HandlingRequestStart and HandlingRequestEnd to introduce a logging system for the application.

Abstract callback function

Inherit from Callback.WebServer.ApplicationServiceStart.AbstractCallbackFunction to create a callback function that can be called by this callback point.