com.bea.wlw.netui.tags.databinding.repeater.choice
Class ChoiceMethod

java.lang.Object
  javax.servlet.jsp.tagext.TagSupport
      javax.servlet.jsp.tagext.BodyTagSupport
          com.bea.wlw.netui.tags.AbstractBaseTag
              com.bea.wlw.netui.tags.databinding.invoke.AbstractCallMethod
                  com.bea.wlw.netui.tags.databinding.invoke.CallMethod
                      com.bea.wlw.netui.tags.databinding.repeater.choice.ChoiceMethod

All Implemented Interfaces:

HtmlConstants, Serializable, javax.servlet.jsp.tagext.BodyTag, javax.servlet.jsp.tagext.IterationTag, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag

public class ChoiceMethod
extends CallMethod

A ChoiceMethod tag is used in order to choose a particular Choice tag whose body should be rendered for the current data item in the Repeater. The ChoiceMethod tag invokes a method on an object and passes parameters from its nested MethodParameter tags. The value of each of these parameters may be taken from the "current" data item using the container.item databinding syntax. The result of evaluating this method is set on the RepeaterItem through the RepeaterItem.setChoiceValue(Object) call. The Choice tags then reach to their RepeaterItem to determine if the body of a particular Choice tag should be rendered.

Attribute Descriptions
Attribute	Required	Runtime Expression Evaluation	Data Bindable
failOnError	No	No	No
	A boolean that if true will cause the tag to fail if any errors are reported invoking the method.
method	No	No	No
	Name of the method in the page flow that will be invoked.
object	Yes	No	Yes
	References an object with an expression on which a choice method should be invoked.
resultId	No	No	No
	The PageContext attribute name where the result, if non-null, is stored.

Additional attributes can be found on the CallMethod tag.

See Also:

Choice, Serialized Form

Example:

In the following example, the <netui-data:choiceMethod> tag calls the isItemsOnSale method, which returns a boolean value. If the return value is true, then the contents of the <netui-data:choice value="true"> tag are rendered; if the return value is false, then the contents of the <netui-data:choice value="false"> tag are rendered.

          <netui-data:repeaterItem>
             <netui-data:choiceMethod object="{pageFlow}" method="isItemOnSale">
                 <netui-data:methodParameter value="{container.item.quantityavailable}"/>
             </netui-data:choiceMethod>
             <netui-data:choice value="true">
                 <tr class="row" bgcolor="#FF9999">
                     <td><netui:label value="{container.item.itemnumber}"/></td>
                     <td><netui:label value="{container.item.itemname}"/></td>
                     <td><netui:label value="{container.item.quantityavailable}"/></td>
                     <td><netui:label value="{container.item.price}"/> Clearance Item</td>
                  </tr>
             </netui-data:choice>
             <netui-data:choice value="false">
                 <tr class="row">
                     <td><netui:label value="{container.item.itemnumber}"/></td>
                     <td><netui:label value="{container.item.itemname}"/></td>
                     <td><netui:label value="{container.item.quantityavailable}"/></td>
                     <td><netui:label value="{container.item.price}"/></td>
                 </tr>
             </netui-data:choice>
          </netui-data:repeaterItem>

Sample Code

[BEA_HOME]\weblogic81\samples\workshop\SamplesApp\WebApp\tagSamples\netui_databinding\choice

Beadoc.see:

<netui-data:choice> Tag Sample, Presenting Complex Data Sets in JSPs (Repeater Tags section)

Beadoc.tagdescription:

The <netui-data:choiceMethod> tag invokes a decision method on the basis of which a particular Choice tag is rendered. The <netui-data:choiceMethod> tag makes its decision by invoking a method on an object. (Parameters are passed to the method from nested MethodParameter tags. The value of each of these parameters may be taken from the "current" data item using the expression {container.item...}.)

Nested Class Summary

Nested classes/interfaces inherited from class com.bea.wlw.netui.tags.databinding.invoke.AbstractCallMethod

AbstractCallMethod.ParamNode

Field Summary

Fields inherited from class com.bea.wlw.netui.tags.AbstractBaseTag

ATTR_GENERAL, ATTR_GENERAL_EXPRESSION, ATTR_JAVASCRIPT, ATTR_STYLE, JAVASCRIPT_STATUS, NETUI_UNIQUE_CNT

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 com.bea.wlw.netui.tags.html.HtmlConstants

ACCEPT, ACCESSKEY, ACTION, ALIGN, ALINK, ALT, ANCHOR, BACKGROUND, BASE, BGCOLOR, BODY, BORDER, BR, CAPTION, CELLPADDING, CELLSPACING, CHAR, CHAROFF, CHARSET, CHECKED, CLASS, COLS, COORDS, DIR, DISABLED, DIV, ENCTYPE, FOR, FORM, FORM_GET, FORM_POST, FRAME, HEIGHT, HREF, HREFLANG, HSPACE, HTML, ID, IMAGE, INPUT, INPUT_BUTTON, INPUT_CHECKBOX, INPUT_FILE, INPUT_HIDDEN, INPUT_IMAGE, INPUT_PASSWORD, INPUT_RADIO, INPUT_RESET, INPUT_SUBMIT, INPUT_TEXT, ISMAP, LABEL, LANG, LINK, LONGDESC, MAXLENGTH, METHOD, NAME, ONBLUR, ONCHANGE, ONCLICK, ONDBLCLICK, ONFOCUS, ONKEYDOWN, ONKEYPRESS, ONKEYUP, ONLOAD, ONMOUSEDOWN, ONMOUSEMOVE, ONMOUSEOUT, ONMOUSEOVER, ONMOUSEUP, ONRESET, ONSELECT, ONSUBMIT, ONUNLOAD, OPTION, READONLY, REL, REV, ROWS, RULES, SELECT, SHAPE, SIZE, SPAN, SRC, STYLE, SUMMARY, TABINDEX, TABLE, TARGET, TD, TEXT, TEXTAREA, TITLE, TR, TYPE, USEMAP, VALIGN, VALUE, VLINK, VSPACE, WIDTH

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

EVAL_BODY_BUFFERED, EVAL_BODY_TAG

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

EVAL_BODY_AGAIN

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

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

ChoiceMethod()

Method Summary

int	doEndTag() End this tag's rendering lifecycle.
int	doStartTag() Register this tag with its RepeaterItem parent.
String	getObject() Get the expression that references an object on which to invoke the decision mtehod.
protected String	getObjectName() Get the name of the object that is the target of the invocation.
String	getTagName() Get the name of this tag.
protected void	handleReturnValue(Object result) Handle any value that may be returned from the decision method.
protected void	localRelease() Reset all of the fields of this tag.
protected void	reportErrors() This will report an expression error.
protected Object	resolveObject() Get the object on which an expression the choice method should be executed.
void	setObject(String object) Set the object on which the decision method should be invoked.

Methods inherited from class com.bea.wlw.netui.tags.databinding.invoke.CallMethod

findMethod

Methods inherited from class com.bea.wlw.netui.tags.databinding.invoke.AbstractCallMethod

addParameter, getFailOnError, getMethod, getParameterNodes, getResultId, setFailOnError, setMethod, setResultId

Methods inherited from class com.bea.wlw.netui.tags.AbstractBaseTag

addTagIdMapping, containsExpression, evaluateAttributeToString, evaluateExpression, filter, filter, formatErrorString, formatString, getAttribute, getErrorsReport, getExpressionEvaluator, getJavaScriptUtils, getNearestForm, getNextId, getQualifiedBundleName, getScriptReporter, getUserLocale, hasErrors, isExpression, prepForRendering, registerAttribute, registerError, registerTagError, release, removeAttribute, renderAttribute, renderAttributes, rewriteName, setPageContext, updateExpression, write

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

doAfterBody, doInitBody, getBodyContent, getPreviousOut, setBodyContent

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

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

Constructor Detail

ChoiceMethod

public ChoiceMethod()

Method Detail

getTagName

public String getTagName()

Get the name of this tag. This is used to identify the type of this tag for reporting tag errors.

Overrides:

getTagName in class CallMethod

Returns:

a constant String representing the name of this tag.

setObject

public void setObject(String object)

Set the object on which the decision method should be invoked. The value of this attribute should be an expression

Overrides:

setObject in class CallMethod

Parameters:

object - the object on which to invoke a method

Beadoc.attributedescription:

The object which contains the method to invoke.

Beadoc.attributesyntaxvalue:

string_object

Beadoc.databindable:

true

getObject

public String getObject()

Get the expression that references an object on which to invoke the decision mtehod.

Overrides:

getObject in class CallMethod

Returns:

the value of the object attribute or null if unset

localRelease

protected void localRelease()

Reset all of the fields of this tag.

Overrides:

localRelease in class CallMethod

doStartTag

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

Register this tag with its RepeaterItem parent. The RepeaterItem will adjust its rendering lifecycle based on the presence of a ChoiceMethod tag.

Specified by:

doStartTag in interface javax.servlet.jsp.tagext.Tag

Overrides:

doStartTag in class AbstractCallMethod

Returns:

EVAL_BODY_BUFFERED; if an error occurs, return SKIP_BODY

Throws:

javax.servlet.jsp.JspException - if an error is reported that can not be reported in the page

See Also:

MethodParameter

doEndTag

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

End this tag's rendering lifecycle.

Specified by:

doEndTag in interface javax.servlet.jsp.tagext.Tag

Overrides:

doEndTag in class AbstractCallMethod

Returns:

EVAL_PAGE

Throws:

javax.servlet.jsp.JspException - if an error is reported that can not be reported in the page

See Also:

AbstractCallMethod.getMethod(), AbstractCallMethod.handleReturnValue(java.lang.Object), MethodParameter, ObjectNotFoundException, TypeUtils.convertToObject(java.lang.String, java.lang.Class), String

resolveObject

protected Object resolveObject()
                        throws ObjectNotFoundException

Get the object on which an expression the choice method should be executed.

Overrides:

resolveObject in class CallMethod

Returns:

the object on which to invoke the decision method

Throws:

ObjectNotFoundException

handleReturnValue

protected void handleReturnValue(Object result)

Handle any value that may be returned from the decision method. The result of invoking the decision method is set on the RepeaterItem so that it can be accessed by the Choice tags in a repeater tag's RepeaterItem tag.

Overrides:

handleReturnValue in class AbstractCallMethod

Parameters:

result - the object that resulted from invoking decision method

getObjectName

protected String getObjectName()

Get the name of the object that is the target of the invocation.

Overrides:

getObjectName in class CallMethod

Returns:

a name for the object on which the method will be invoked.

reportErrors

protected void reportErrors()
                     throws javax.servlet.jsp.JspException

Description copied from class: AbstractBaseTag

This will report an expression error.

Overrides:

reportErrors in class AbstractBaseTag

Throws:

javax.servlet.jsp.JspException