Attribute Directive

Declares attributes of custom actions defined in tag files. Used in tag files only.

JSP Syntax

<%@ attribute   name="attribute-name"
   [ required="true | false" ]
   [ fragment="true | false" ]
   [ rtexprvalue="true | false" ]
   [ type="java.lang.String | a non-primitive type"]
   [ description="text" ]
%>

OR

<jsp:directive.attribute attributeDirectiveAttrList />

where attributeDirectiveAttrList is the same as the list for JSP syntax

XML Syntax

<jsp:directive.attribute attributeDirectiveAttrList />

where attributeDirectiveAttrList is the same as the list for JSP syntax

Examples

The Duke's Bookstore example includes a custom tag, called shipDate, that is defined in a tag file, shipDate.tag. The tag file includes an attribute directive that declares the shipDate tag's attribute, shipping:

<%@ attribute name="shipping" required="true" %>

Here is an example of the shipDate tag used in the bookreceipt.jsp page:

<sc:shipDate shipping="${param.shipping}" /> 

Description

The attribute directive allows the declaration of attributes for custom tags in tag files. This is analogous to the attribute element of a TLD file.

Attributes

• name = "attribute-name"

  The unique name of the attribute being declared. A translation error results if more than one attribute directive appears in the same translation unit with the same name. A translation error results if there is an attribute directive with a name attribute equal to the value of the name-given attribute of a variable directive or the dynamic-attributes attribute of a tag directive in this translation unit.

• required="true | false"

  Whether this attribute is required (true) or optional (false). Defaults to false if not specified.

• fragment="true | false"

  Whether this attribute is a fragment to be evaluated by the tag handler (true) or a normal attribute to be evaluated by the container prior to being passed to the tag handler. If this attribute is true:

  • You do not specify the rtexprvalue attribute. The container fixes the rtexprvalue attribute at true.
  • You do not specify the type attribute. The container fixes the type attribute at javax.servlet.jsp.tagext.JspFragment.

  Defaults to false.

• rtexprvalue="true | false"

  Whether the attribute's value may be dynamically calculated at runtime by a scriptlet expression. Unlike the corresponding TLD element, this attribute defaults to true.

• type="java.lang.String | a non-primitive type"

  The runtime type of the attribute's value. Defaults to java.lang.String if not specified. It is a translation error to specify a primitive type.

• description="text"

  Description of the attribute. Defaults to no description.

抱歉！大部分内容只有英文