Package jakarta.servlet.jsp.tagext

Class TagAttributeInfo

java.lang.Object
jakarta.servlet.jsp.tagext.TagAttributeInfo
public class TagAttributeInfo extends Object
Information on the attributes of a Tag, available at translation time. This class is instantiated from the Tag Library Descriptor file (TLD).

Only the information needed to generate code is included here. Other information like SCHEMA for validation belongs elsewhere.

Note from the Expert Group:
This should have been designed as an interface. Every time we change the TLD, we need to add a new constructor to this class (not good). This class should only be instantiated by container implementations (not by JSP developers).

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    ID
    "id" is wired in to be ID.

  • Constructor Summary

    Constructors
    Constructor
    Description
    TagAttributeInfo(String name, boolean required, String type, boolean reqTime)
    Constructor for TagAttributeInfo.
    TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment)
    JSP 2.0 Constructor for TagAttributeInfo.
    TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment, String description, boolean deferredValue, boolean deferredMethod, String expectedTypeName, String methodSignature)
    JSP 2.1 Constructor for TagAttributeInfo.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    canBeRequestTime()
    Whether this attribute has been specified in the TLD as rtexprvalue.
    String
    getDescription()
    Gets the description string of this tag attribute.
    String
    getExpectedTypeName()
    Returns the name of the expected type (as a String) of this deferred value attribute.
    static TagAttributeInfo
    getIdAttribute(TagAttributeInfo[] a)
    Convenience static method that goes through an array of TagAttributeInfo objects and looks for "id".
    String
    getMethodSignature()
    Returns the expected method signature of this deferred method attribute.
    String
    getName()
    The name of this attribute.
    String
    getTypeName()
    The type (as a String) of this attribute.
    boolean
    isDeferredMethod()
    Returns true if this attribute is to be passed a MethodExpression so that expression evaluation can be deferred.
    boolean
    isDeferredValue()
    Returns true if this attribute is to be passed a ValueExpression so that expression evaluation can be deferred.
    boolean
    isFragment()
    Whether this attribute is of type JspFragment.
    boolean
    isRequired()
    Whether this attribute is required.
    String
    toString()
    Returns a String representation of this TagAttributeInfo, suitable for debugging purposes.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • ID

      public static final String ID
      "id" is wired in to be ID. There is no real benefit in having it be something else IDREFs are not handled any differently.
      See Also:

  • Constructor Details

    • TagAttributeInfo

      public TagAttributeInfo(String name, boolean required, String type, boolean reqTime)
      Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under request from some JSP code that is parsing a TLD (Tag Library Descriptor).
      Parameters:
      name - The name of the attribute.
      required - If this attribute is required in tag instances.
      type - The name of the type of the attribute.
      reqTime - Whether this attribute holds a request-time Attribute.

    • TagAttributeInfo

      public TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment)
      JSP 2.0 Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under request from some JSP code that is parsing a TLD (Tag Library Descriptor).
      Parameters:
      name - The name of the attribute.
      required - If this attribute is required in tag instances.
      type - The name of the type of the attribute.
      reqTime - Whether this attribute holds a request-time Attribute.
      fragment - Whether this attribute is of type JspFragment
      Since:
      JSP 2.0

    • TagAttributeInfo

      public TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment, String description, boolean deferredValue, boolean deferredMethod, String expectedTypeName, String methodSignature)
      JSP 2.1 Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under request from some JSP code that is parsing a TLD (Tag Library Descriptor).
      Parameters:
      name - The name of the attribute.
      required - If this attribute is required in tag instances.
      type - The name of the type of the attribute.
      reqTime - Whether this attribute holds a request-time Attribute.
      fragment - Whether this attribute is of type JspFragment
      description - The description of the attribute.
      deferredValue - Whether this attribute is a deferred value.
      deferredMethod - Whether this attribute is a deferred method. rtexpr or deferred value.
      expectedTypeName - The name of the expected type of this deferred value (or null if this is not a deferred value).
      methodSignature - The expected method signature of this deferred method (or null if this is not a deferred method).
      Since:
      JSP 2.1

  • Method Details

    • getName

      public String getName()
      The name of this attribute.
      Returns:
      the name of the attribute

    • getTypeName

      public String getTypeName()
      The type (as a String) of this attribute.

      This method must return "jakarta.el.ValueExpression" if isDeferredValue() returns true and canBeRequestTime() returns false. It must return "jakarta.el.MethodExpression" if isDeferredMethod() returns true. It must return "java.lang.Object" if isDeferredValue() returns true and canBeRequestTime() returns true.

      Returns:
      the type of the attribute

    • canBeRequestTime

      public boolean canBeRequestTime()
      Whether this attribute has been specified in the TLD as rtexprvalue. If true, this means the attribute can hold a request-time value.
      Returns:
      true if the attribute has been specified in the TLD as rtexprvalue

    • isRequired

      public boolean isRequired()
      Whether this attribute is required.
      Returns:
      if the attribute is required.

    • getIdAttribute

      public static TagAttributeInfo getIdAttribute(TagAttributeInfo[] a)
      Convenience static method that goes through an array of TagAttributeInfo objects and looks for "id".
      Parameters:
      a - An array of TagAttributeInfo
      Returns:
      The TagAttributeInfo reference with name "id"

    • isFragment

      public boolean isFragment()
      Whether this attribute is of type JspFragment.
      Returns:
      if the attribute is of type JspFragment
      Since:
      JSP 2.0

    • getDescription

      public String getDescription()
      Gets the description string of this tag attribute.
      Returns:
      the description string of this tag attribute

    • isDeferredValue

      public boolean isDeferredValue()
      Returns true if this attribute is to be passed a ValueExpression so that expression evaluation can be deferred.

      If this method returns true, then getTypeName() must return "jakarta.el.ValueExpression".

      The getExpectedType() method can be used to retrieve the expected type this value expression will be constructed with.

      Returns:
      true if this attribute accepts a deferred value; false otherwise.
      Since:
      JSP 2.1

    • isDeferredMethod

      public boolean isDeferredMethod()
      Returns true if this attribute is to be passed a MethodExpression so that expression evaluation can be deferred.

      If this method returns true, then getTypeName() must return "jakarta.el.MethodExpression".

      The getMethodSignature() method can be used to retrieve the expected method signature this method expression will be constructed with.

      Returns:
      true if this attribute accepts a deferred method; false otherwise.
      Since:
      JSP 2.1

    • getExpectedTypeName

      public String getExpectedTypeName()
      Returns the name of the expected type (as a String) of this deferred value attribute.

      This method returns null if isDeferredValue() returns false.

      Returns:
      the name of the expected type
      Since:
      JSP 2.1

    • getMethodSignature

      public String getMethodSignature()
      Returns the expected method signature of this deferred method attribute.

      This method returns null if isDeferredMethod() returns false.

      Returns:
      the method signature
      Since:
      JSP 2.1

    • toString

      public String toString()
      Returns a String representation of this TagAttributeInfo, suitable for debugging purposes.
      Overrides:
      toString in class Object
      Returns:
      a String representation of this TagAttributeInfo