There are different ways to trigger a Task execution process:
There are different methods to trigger a Task execution process:
- Using the tag *RunOnTrigger*
-
- Using the tags *SartDate* and *StopDate*
- Using the filtering tag *FileType*
The most flexible method is actually the *FileType* filter, as everything is treated as a file being processed
## Using *FileType* filter method
The presence of a dedicated trigger file (eg. TR$PROCESSOR.*.trigger) , or also any other file, filtered by the <FileType> expression,
acts as a driver for the Task execution. This allows than to create a list of trigger files that the DES can then elaborate in a FIFO queue.
Because the Date for example is often used as input parameter for a processing time series for example,
the Date has to be passed as input parameter to the Task executing a particular job.
One approach to implement this, is to ensure that the trigger file TR$PROCESSOR.*.trigger includes the date at a certain position, i.e position 5 (. separated):
So the implemented wrapper Script (Perl, Python, Shell) or Java Class for the Task can extract the processing parameters as needed, i.e. The date to be processed.
The trigger file itself might contain even a more structured meta information in form of XML for example.
By convention the trigger file should have the following naming convention: