org.apache.beehive.netui.tags.databinding.script
Class GetData

Object
  TagSupport
      BodyTagSupport
          AbstractClassicTag
              GetData

All Implemented Interfaces:

Serializable, BodyTag, IterationTag, JspTag, Tag, INetuiTag

public class GetData
extends AbstractClassicTag

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

In the following example, the getData tag gets the value of a property in the page flow and makes it available to the JSP via the JSP EL implicit object ${pageScope}.

     <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:

     ${pageScope.myData}
 

     <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 example 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:span 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>
 

See Also:

Serialized Form

Example

In this first example, the <netui-data:getData> tag loads data into the PageContext's attribute map. It can then be accessed using the JspContext.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 example 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:span 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>
 

GetData

public GetData()

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 interface INetuiTag

Specified by:

getTagName in class AbstractClassicTag

Returns:

a constant String representing the name of this tag.

setValue

public void setValue(Object value)

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

Parameters:

value - the expression to evaluate

setResultId

public void setResultId(String resultId)

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

Parameters:

resultId - the String key

doStartTag

public int doStartTag()

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

Specified by:

doStartTag in interface Tag

Overrides:

doStartTag in class BodyTagSupport

Returns:

Tag.SKIP_BODY

doEndTag

public int doEndTag()
             throws JspException

Evaluate the expression at the value attribute and store the result in the PageContext under the attribute key specified in setResultId(String). 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 Tag

Overrides:

doEndTag in class BodyTagSupport

Returns:

Tag.EVAL_PAGE

Throws:

JspException

localRelease

protected void localRelease()

Reset all of the fields of this tag.

Overrides:

localRelease in class AbstractClassicTag