HTTP triggers allow you to monitor a URI (Uniform Resource Identifier) for changes. Specifically, you can poll the Last-Modified and Content-MD5 HTTP header fields for changes. You can configure the polling interval (e.g, every 60 seconds) and optionally set the start and expiry date of the trigger. The screenshot below illustrates a sample HTTP trigger.
The subsection below explains how to define the settings of HTTP triggers.
HTTP trigger overview
HTTP triggers have the following parameters: Check, Of URI, Polling interval, Wait N seconds for settle, Start, Expires, Time zone, Enabled (see descriptions below).
Specifies how the trigger should poll the URI. The following options are available:
•HTTP Header Date instructs the system to check the Last-Modified HTTP header. If the Last-Modified HTTP header is missing, the Content-MD5 header is checked (see next option).
•Content instructs the system to check the optional Content-MD5 HTTP header. This is a 128-bit digest used as a message integrity check. If the MD5 header has changed after the polling interval has passed, the trigger fires. If the header is not provided by the server, the content is retrieved and hashed locally.
In this field, you need to specify the URI you would like to check for changes.
Specifies the frequency in seconds, with which the URI will be polled.
The server will wait N seconds before checking the file. If the file is still in the specified location and has not changed during the settle period, the job will start. Otherwise, the server will wait again for the specified period and then check again if the file has changed since the last check. This option allows FlowForce Server to wait until the file has been fully written and ensure that the file is not being edited/changed by anybody.
Defines the trigger's starting date and time. This is an optional field. When you click in the date field, a pop-up calendar opens, which allows you to select the start date. You can also type in the date manually.
Defines the date and time when the trigger expires.
Defines the time zone applicable to the start and expiry date and time. The default time zone is defined in the server administration settings.
The Enabled check box allows you to enable or disable the trigger. This option is useful when you create and test new jobs.