Description

This tag can be used to parameterize other tags.

The include tag and bean tag are examples of such tags.

The parameters can be added with or without a name as key. If the tag provides a name attribute the parameters are added using the {@link Component#addParameter(String, Object) addParamter} method. For unnamed parameters the Tag must implement the UnnamedParametric interface defined in this class (e.g. The TextTag does this).

This tag has the following two paramters.

• name (String) - the name of the parameter
• value (Object) - the value of the parameter
• suppressEmptyParameters (boolean) - whether to suppress empty parameters

Note: When you declare the param tag, the value can be defined in either a value attribute or as text between the start and end tag. Struts behaves a bit different according to these two situations. This is best illustrated using an example:
<param name="color">blue</param> <-- (A) -->
<param name="color" value="blue"/> <-- (B) -->
In the first situation (A) the value would be evaluated to the stack as a java.lang.String object. And in situation (B) the value would be evaluated to the stack as a java.lang.Object object.
For more information see WW-808.

Parameters

Dynamic Attributes Allowed: false
Name	Required	Default	Evaluated	Type	Description
name	false		false	String	Name of Parameter to set
suppressEmptyParameters	false	false	false	Boolean	Whether to suppress empty parameters
value	false	The value of evaluating provided name against stack	false	String	Value expression for Parameter to set

Examples

where the key will be the identifier and the value the result of an OGNL expression run against the current ValueStack.