VI Iterate Output Object

The Visual Integrator (VI) Iterate output object iterates a VI task or task list on each row of the input data flow, varying parameters based on input flow columns.

Icon for the VI Iterate output object

The Iterate object is similar to the Execrows object, except the Iterate object runs VI tasks instead of running external commands.

NOTE: Since the introduction of DI-Production, DI highly recommends using a Production script to loop through a VI script in order to achieve the same results as using the Iterate output object and multiple tasks in VI.

The Iterate output object has Closedthree panes where you set attributes.

VI Iterate Object All Panes

You set attributes for the Iterate output object in the Closedobject attributes pane.

Example of VI Iterate output object's attributes

Attribute Description
Input

Defines the object from which the data flow arrives. Use one of the following methods to attach the Iterate output object to an input data flow object:

  • Right-click the data flow object, and click New Object after this > Output > Iterate.

  • Place the Iterate output object on the task flow, and click its Input attribute's browse button. Move the pointer to the canvas and note that a dotted-line connector is attached to the Iterate output object. Attach this connector to the data flow object.

    NOTE: The Iterate output object's Input attribute is populated with the name of the input data flow object.
Task

Defines the task to iterate from the available tasks that exist within the script.

This task should be designed to perform an action on every row of the input data flow based on the parameters set up in the column grid.

Choose a task from the Task pull-down list.

The Task and Task_List attributes are mutually exclusive, but one must be defined.
Task_List

Defines the task list to iterate from the available task lists that exist within the script.

This task list should be designed such that the individual tasks perform actions on every row of the input data flow based on the parameters set up in the column grid.

Choose a task list from the Task_List pull-down list.

The Task and Task_List attributes are mutually exclusive, but one must be defined.
Error_Action

Defines the action to take if an error occurs while running a task or task list.

  • continue—Continues running the task with the next set of parameters.
  • exit—Stops iterating and returns an error.

Each object has an area where you can enter comments.

It is a DI best practice to enter a note for every object in a VI script. You can set a VI preference to give a warning for each object without a note. For more information, see Visual Integrator Preferences.

ClosedIterate output object with comments

Example of Iterate output object with comments

You set which input columns are set for use as VI parameters in the Closedcolumn grid.

Example of a VI Iterate output object's column grid

Attribute Description
Input Column Displays the name of each input column. This attribute is read-only.
Source Object Displays the name and object type of the source object. Double-click the Source Object for a column to change the task flow focus to that object.
Parameter

Select the Parameter Closedcheck box for each input column you want available as VI parameters.

Example of VI Iterate output object with input column selected as parameter

Any input columns with a check mark in the parameter column automatically populate the ClosedParameters tab for the script.

Example of VI script parameters tab populated by choices in Iterate output object

See also: Parameter Example: Using Iterate.