Input tasks

Input tasks are the starting point to any process and determine what file this process will being with. Each process must begin with an Input task, and although a given process may have multiple Input tasks, no task can have more than one initial Input task.

Initial Input tasks

Initial Input tasks are always at the beginning of a process and are always triggered when the process starts. The process itself may start on a schedule or poll at regular intervals, which means the initial Input task only runs whenever the process is set to run. For more information about what happens outside of the process scheduled times and to learn how to set the schedule, see Process properties.

If an error occurs during an initial Input task, the On Error tab is never triggered. See Using the On Error tab.

Input tasks may either poll a specific location, or wait for jobs to be sent to a specific PReS Workflow Service. It is not recommended to have two Initial Input tasks capturing the same input location, for the following reasons:

  • It is a "hit and miss" to know which of the two tasks will pick up the file. This is an issue if the two processes are different.
  • One of the processes may process a file quicker than another and finish first, which may be an issue if the processing relies on FIFO (First In, First Out).
  • One process may error out as it's trying to capture an input that's currently being read by another one. This causes issues if the process is on a schedule and only runs once per period.

It is important to note that Initial Input tasks process files one at a time, and will return to the Input task once the current file has finished processing. Each time it returns to the Input task, it again only captures one single file. It does this until there are no more files in the folder and will also capture any new file that was added during the time it processed other files. Once no more files are found, it stops processing until it is scheduled to run again.

This is an important consideration when scheduling a task, as the Folder Capture task will keep capturing files as long as new files are added, even if it means continuing to capture and process outside its scheduled time. It is also important that while the Folder Capture input task is processing files it keeps a copy of each file in a temporary folder, and will not delete any of these files until it has finished processing all of them. This may cause issues with running out of disk space.

Secondary Input tasks

Secondary Input tasks are placed in the process like an Action task would and will replace the job file in the process with the file they retrieve. Since they are part of the process, they can use data from previous tasks to pull data from a variable location. Secondary Inputs do not follow a separate schedule from the process - they are automatically run when the process triggers them.

Considerations

  • If your initial Input task does not start, either because there is no data to capture or because the process is out of its schedule, any secondary Input task will not run either.
  • Secondary Input tasks replace both the job file and the job info variables. They do not change local and global variables.
  • If your secondary Input task creates a job file using a different emulation, you will need to use a Change Emulation task after the secondary Input task to correctly change to that emulation. (For more information about emulations, see About data emulation.)

Properties common to all input tasks

The Other tab in the Task Properties dialog (see Task properties) is common to all Input tasks.

"Other" Tab
  • Job Information group
    • Information elements: Indicates what Job Info variables are automatically created by the input task.
    • Add lines before first data page: Using the arrows keys you can add any job information directly at the beginning of your data file.
  • Backup input files: Check this to save a copy of each data file that is captured by your input. These files are saved in the PReS Workflow Tools working folders under the "Backup" folder.
    To navigate quickly to the Workflow working folders, press the keyboard shortcut CTRL+ALT+Shift+F4 from within the Workflow configuration tool.
    The number of days to keep backups of jobs processed by input tasks is set per process; see Process properties.
  • Backup filename: Enter the file name that you wish the input data file backup to be saved under.
  • Delete Existing Metadata: Check to remove any Metadata from memory. This option is disabled on initial input tasks, and is checked by default on secondary input tasks.

Available Input tasks

The SFTP Input task also appears in the Input category when it is installed. (It isn't installed by default.)