org.chwf.taglib.jutil
Class ParamTag

java.lang.Object
  |
  +--javax.servlet.jsp.tagext.TagSupport
        |
        +--javax.servlet.jsp.tagext.BodyTagSupport
              |
              +--org.chwf.taglib.base.LifeCycleBodyTagSupport
                    |
                    +--org.chwf.taglib.jutil.ParamTag

All Implemented Interfaces:

javax.servlet.jsp.tagext.BodyTag, Parameterized, java.io.Serializable, javax.servlet.jsp.tagext.Tag

Direct Known Subclasses:

AttributeTag

public class ParamTag

extends LifeCycleBodyTagSupport

Tag handler for the <param> tag. It has one attribute, "name", which is the name of the generated parameter. This handler sets the parameter or attribute value in one of two ways:

• If the trimmed tag body is not an empty string, it sets the value equal to the processed contents of the tag body.
• Otherwise, it sets the parameter value to the first matching web application variable, searching first request parameters, then web application scopes in order (page to application).

Once the parameter is set, the handler retrieves its parent tag. If the parent tag implements the Parameterized interface, it calls the tags addParameter() method. If not, it throws a JspException.

Author:

Paul Strack

See Also:

Serialized Form

Fields inherited from class javax.servlet.jsp.tagext.BodyTagSupport

bodyContent

Fields inherited from class javax.servlet.jsp.tagext.TagSupport

id, pageContext

Fields inherited from interface javax.servlet.jsp.tagext.BodyTag

EVAL_BODY_TAG

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

ParamTag()

Method Summary

void	cleanup() Clean up data for tag handler reuse and pooling.
int	doEnd() Set parameter value from tag body or scoped variable.
java.lang.Object	findObject() Find the object for the tag or the default object if no object was specified.
java.lang.String	getName() The parameter name.
java.lang.String	getObject() Get object name used to lookup the object.
protected Parameterized	getParametrizedTag() Derived parametrized tag to be updated.
java.lang.String	getProperty() The object property being retrieved.
void	setName(java.lang.String name) The parameter name.
void	setObject(java.lang.String objectName) The object name.
void	setProperty(java.lang.String property) The object property being retrieved.

Methods inherited from class org.chwf.taglib.base.LifeCycleBodyTagSupport

addAttribute, addParameter, doEndTag, doStart, doStartTag, getAttribute, getAttributeNames, getParameter, getParameterNames, init, printAttributes

Methods inherited from class javax.servlet.jsp.tagext.BodyTagSupport

doAfterBody, doInitBody, getBodyContent, getPreviousOut, release, setBodyContent

Methods inherited from class javax.servlet.jsp.tagext.TagSupport

findAncestorWithClass, getId, getParent, getValue, getValues, removeValue, setId, setPageContext, setParent, setValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.jsp.tagext.Tag

getParent, setPageContext, setParent

Constructor Detail

ParamTag

public ParamTag()

Method Detail

cleanup

public void cleanup()

Clean up data for tag handler reuse and pooling. Should be overridden in tag handler. Subclasses should always invoke their superclass's cleanup method: super.cleanup()

Overrides:

cleanup in class LifeCycleBodyTagSupport

setName

public void setName(java.lang.String name)

The parameter name.

Parameters:

name - The parameter name.

getName

public java.lang.String getName()

The parameter name.

Returns:

The parameter name.

setProperty

public void setProperty(java.lang.String property)
                 throws javax.servlet.jsp.JspException

The object property being retrieved. Defaults to var if absent.

Parameters:

property - The property name.

Throws:

javax.servlet.jsp.JspException - If the property cannot be initialized.

getProperty

public java.lang.String getProperty()

The object property being retrieved. Defaults to var if absent.

Returns:

The property name.

setObject

public void setObject(java.lang.String objectName)
               throws javax.servlet.jsp.JspException

The object name. Always optional. The tag will use the default object if no object can is specified.

Parameters:

objectName - The object's name for lookup.

Throws:

javax.servlet.jsp.JspException - If the object filter cannot be found.

getObject

public java.lang.String getObject()

Get object name used to lookup the object.

Returns:

The object name.

findObject

public java.lang.Object findObject()

Find the object for the tag or the default object if no object was specified.

Returns:

The object.

doEnd

public int doEnd()
          throws javax.servlet.jsp.JspException

Set parameter value from tag body or scoped variable.

Overrides:

doEnd in class LifeCycleBodyTagSupport

Returns:

SKIP_BODY

Throws:

javax.servlet.jsp.JspException - If not nested in a parametrized tag.

getParametrizedTag

protected Parameterized getParametrizedTag()

Derived parametrized tag to be updated.

Returns:

The parametrized tag.