com.bea.wlw.netui.tags.databinding.script
Class GetData

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.script.GetData

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 GetData
extends AbstractBaseTag

This tag evaluates an expression and places the result of expression evaluation in a JSP's PageContext. This can be used to extract objects from forms, page flows, and other objects that can be databound; once in the JSP, scriptlet can be written using these objects by accessing them through the JspContext.getAttribute(java.lang.String) method.

Attribute Descriptions
Attribute	Required	Runtime Expression Evaluation	Data Bindable
resultId	Yes	No	Yes
	The String identifier under which the Object resulting from expression evaluation will be stored.
value	Yes	No	Yes
	The expression that references the data to store in the PageContext attribute map.

See Also:

<netui-data:getData> Tag Sample, Using Data Binding in Page Flows (PageContext section), javax.servlet.jsp.PageContext, Serialized Form

Example:

In this first sample, the <netui-data:getData> tag loads data into the PageContext object. You can subsequently access the data through the PageContext's getAttribute(String) method.

    <netui:form action="lastNameAction" focus="lastname">
         ...
         <netui-data:getData resultId="first" value="{actionForm.firstname}"/>
         ...
         <% 
             String firstName = (String) pageContext.getAttribute("first");
             System.out.println("First Name = " + firstName);
             ...
         %>
         ...
     </netui:form>

This next sample shows how to use <netui-data:getData> and the PageContext inside of other containers, in this case a <netui-data:repeater> tag. The <netui-data:getData> below extracts each element as the <netui-data:repeater> iterates over the data set and writes it to the Java console:

    <netui-data:repeater dataSource="{pageFlow.strArr}">
         ...
         <netui-data:repeaterItem>
             <netui:label value="{container.item}" />
             <netui-data:getData resultId="item" value="{container.item}"/>
             <% 
                 String currentItem = (String) pageContext.getAttribute("item");
                 System.out.println(currentItem);
                 ...
             %>
          </netui-data:repeaterItem>
          ...
      </netui-data:repeater>

Code Sample

[BEA_HOME]/weblogic81/samples/workshop/SamplesApp/WebApp/tagSamples/netui_databinding/getData/

Beadoc.tagdescription:

This tag evaluates an expression and places the result in the javax.servlet.jsp.PageContext object, where the data is available to JSP scriptlets. This tag can be used to extract data from forms, Controller files, and any data binding context and make it available to scriptlets.

The following <netui-data:getData> tag extracts data from the Controller file and places it in the myData field of the PageContext object:

    <netui-data:getData resultId="myData" value="{pageFlow.myData}"/>

The following scriptlet extracts the data from the PageContext object and writes it to the rendered HTML:

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

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

GetData()

Method Summary

int	doEndTag() Evaluate the expression at the value attribute and store the result in the PageContext under the attribute key resultId.
int	doStartTag() Start the tag evaluation.
String	getResultId() Get the key under which the result of evaluating the expression will be stored in the PageContext.
String	getTagName() Get the name of this tag.
String	getValue() Get the expression to evaluate.
protected void	localRelease() Reset all of the fields of this tag.
void	setResultId(String resultId) Set the String key under which the result of evaluating an expression will be stored in the PageContext.
void	setValue(String value) Set the expression to evaluate.

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

GetData

public GetData()

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.

setValue

public void setValue(String value)

Set the expression to evaluate.

Parameters:

value - the expression to evaluate

Beadoc.attributedescription:

The data binding expression to evaluate. The result will be stored in the PageContext object as specified in the resultId attribute.

Beadoc.attributesyntaxvalue:

expression_value

Beadoc.databindable:

true

getValue

public String getValue()

Get the expression to evaluate.

Returns:

the expression to evaluate

setResultId

public void setResultId(String resultId)

Set the String key under which the result of evaluating an expression will be stored in the PageContext.

Parameters:

resultId - the String key

Beadoc.attributedescription:

Specifies the property of the PageContext object where the data will be stored.

Beadoc.attributesyntaxvalue:

string_resultId

Beadoc.databindable:

false

getResultId

public String getResultId()

Get the key under which the result of evaluating the expression will be stored in the PageContext.

Returns:

the String key

doStartTag

public int doStartTag()

Start the tag evaluation. This tag ignores its body content.

Specified by:

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

Overrides:

doStartTag in class javax.servlet.jsp.tagext.BodyTagSupport

Returns:

SKIP_BODY

doEndTag

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

Evaluate the expression at the value attribute and store the result in the PageContext under the attribute key resultId. If an existing key in the PageContext's attribute map exists, a warning will be written to the log file. If errors occur during expression evaluation, they will be reported in the JSP page. If the value returned by the expression is null, an attribute named resultId will be removed from the PageContext's attribute map.

Specified by:

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

Overrides:

doEndTag in class javax.servlet.jsp.tagext.BodyTagSupport

Returns:

EVAL_PAGE

Throws:

javax.servlet.jsp.JspException

localRelease

protected void localRelease()

Reset all of the fields of this tag.

Overrides:

localRelease in class AbstractBaseTag