You can constrain the input parameters that users provide when they run workflows by setting parameter properties.

The possible properties for each type of parameter are listed in the following table.

Table 1. Workflow Input Parameter Properties

Parameter Property	Parameter Type	Description
Maximum string length	String	Sets a maximum length for the parameter.
Minimum string length	String	Sets a minimum length for the parameter.
Matching regular expression	String	Validates the input using a regular expression.
Maximum number value	Number	Sets a maximum value for the parameter.
Minimum number value	Number	Sets a minimum value for the parameter.
Number format	Number	Formats the input for the parameter.
Enumeration	Any	Specifies an ordered list of possible values.
Mandatory	Any	Makes the parameter mandatory.
Choice from another parameter or attribute	Any	Derives possible user inputs from another parameter. For example, if this parameter is an SSH:File and a parameter in a previous step is an SSH:Folder, you can set this property to limit the possible input parameter values to files contained in the SSH:Folder.
Predefined list of elements	Any	Similar to Choice from another parameter or attribute, but the user can add a different value to the one derived from the preceding parameter.
Show parameter input	Any	Shows or hides a parameter text box in the presentation dialog box, depending on the value of a preceding Boolean parameter.
Hide parameter input	Any	Similar to Show parameter input but takes the negative value of a previous Boolean parameter.
Matching expression	Any parameter type obtained from a plug-in	The input parameter matches a given expression.
Show in inventory	Any parameter type obtained from a plug-in	If set, you can run the present workflow on any object of this type by right-clicking it in the inventory view and selecting Execute operation.
Specify root object in selector	Any parameter type obtained from a plug-in	Specifies the root object if the selector for this parameter is a hierarchical list selector.
Select as	Any parameter type obtained from a plug-in	Use a list or hierarchical list selector to select the parameter.
Default value	Any	Default value for this parameter.
Custom validation	OGNL scriptable validation	If the invocation of the OGNL expression returns a String, the validation shows this String as the text of the error result.
Auto start	Boolean	Starts the workflow automatically.
Mandatory input	Boolean	Makes this parameter mandatory. The workflow will not run without it.