com.bea.wlw.netui.tags.databinding.invoke
Class CallMethod

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

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

Direct Known Subclasses:

CallPageFlow, ChoiceMethod

public class CallMethod
extends AbstractCallMethod

An abstract base class for tags that are capable of reflectively invoking methods. Specializations of this tag provide method implementations that locate the object on which to invoke the method and that handle any return value from the invoked method.

The CallMethod tag can have child tags of type MethodParameter; these tags must be in the same order as the parameter list in the method signature of the method that will be invoked. To invoke an overloaded method, the MethodParameter.setValue(java.lang.String)} property must be set to the String name of the type to pass to the method. If the type attribute values on nested MethodParameter tags do not match any method signature, an error will be reported in the page.

Attribute Descriptions
Attribute	Required	Runtime Expression Evaluation	Data Bindable
failOnError	No	No	No
	A boolean that if true will cause the tag to report any method invocation errors in-line in the rendered page.
method	No	No	No
	The method to invoke on an object.
object	No	No	Yes
	References an object on which the method will be invoked.
resultId	No	No	No
	The PageContext attribute name where the result, if non-null, is stored.

See Also:

MethodParameter, CallControl, CallPageFlow, Serialized Form

Example:

In this example, the JSP calls the Page Flow method getShippingState(int i). One parameter is passed to the method: the integer 1.

  <netui-data:callMethod object="{pageFlow}" method="getShippingState" failOnError="true" resultId="test">
      <netui-data:methodParameter type="int" value="1" />
  </netui-data:callMethod>
 

Code Sample

[BEA_HOME]/weblogic81/samples/workshop/SamplesApp/tagSamples/netui_databinding/callMethod/callMethod.jsp

Beadoc.see:

<netui-databinding:callMethod> Tag Sample

Beadoc.tagdescription:

This tag is used to call methods on any Java classes within the current Workshop Project.

The controlId attribute is used to specify the cclass to be called. The value returned is stored in the {pageContext...} data binding context object under the attribute specified by the resultId attribute.

For example, if you call a Java class with the following <netui-data:callMethod> tag...

    <netui-data:callMethod 
          object="{pageFlow}" 
          method="hello" 
          resultId="helloMessage" 
          />

...the result of the call is stored in the {pageContext...} data binding context under the attribute helloMessage.

The result can be retrieved with the data binding expression {pageContext.helloMessage}

   <netui:label value="{pageContext.helloMessage}"/>

In a scriptlet, the result can be retrieved by calling the getAttribute() method on the javax.servlet.jsp.PageContext object:

    <%= pageContext.getAttribute("helloMessage") %>

Note that only synchronous methods can be called with <netui-data:callMethod>. For handling asynchronous methods see the help topic Calling Web Services and Custom Java Controls From A Page Flow

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

CallMethod()

Method Summary

protected Method	findMethod(Object target, String methodName, boolean verifyTypes) The default findMethod implementation is an uncached search of all of the methods available on the Class of the target
String	getObject() Get the object on which a method will be invoked.
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	localRelease() Reset all of the fields of this tag.
protected Object	resolveObject() Resolve the object on which the method should be invoked.
void	setObject(String object) Set the object on which to invoke a method.

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

addParameter, doEndTag, doStartTag, getFailOnError, getMethod, getParameterNodes, getResultId, handleReturnValue, 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, reportErrors, 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

CallMethod

public CallMethod()

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.

Specified by:

getTagName in class AbstractBaseTag

Returns:

a constant String representing the name of this tag.

setObject

public void setObject(String object)

Set the object on which to invoke a method.

Parameters:

object - the object on which to invoke a method

Beadoc.attributedescription:

A string or data binding expression that names the class on which to call a method.

Beadoc.attributesyntaxvalue:

string_or_expression_object

Beadoc.databindable:

Read Only

getObject

public String getObject()

Get the object on which a method will be invoked.

localRelease

protected void localRelease()

Reset all of the fields of this tag.

Overrides:

localRelease in class AbstractCallMethod

resolveObject

protected Object resolveObject()
                        throws ObjectNotFoundException

Description copied from class: AbstractCallMethod

Resolve the object on which the method should be invoked. If there are errors resolving this object, this method will throw an ObjectNotFoundException.

If the object is not found but no exception occurred, this method should return null.

Specified by:

resolveObject in class AbstractCallMethod

Returns:

the object on which to reflectively invoke the method.

Throws:

ObjectNotFoundException - if an exception occurred attempting to resolve an object

findMethod

protected final Method findMethod(Object target,
                                  String methodName,
                                  boolean verifyTypes)

Description copied from class: AbstractCallMethod

The default findMethod implementation is an uncached search of all of the methods available on the Class of the target

Overrides:

findMethod in class AbstractCallMethod

Parameters:

target - the object from which to find the method

methodName - the name of the method to find

verifyTypes - a boolean that if true will match the type names in addition to the String method name

Returns:

a Method object matching the methodName and types, if verifyTypes is true. null otherwise.

getObjectName

protected String getObjectName()

Description copied from class: AbstractCallMethod

Get the name of the object that is the target of the invocation. This is a generic method for this tag that enables more specific error reporting.

Specified by:

getObjectName in class AbstractCallMethod

Returns:

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