org.omnifaces.taghandler
Class ValidateUniqueColumn

java.lang.Object
  javax.faces.view.facelets.TagHandler
      org.omnifaces.taghandler.ValidateUniqueColumn

All Implemented Interfaces:

java.util.EventListener, javax.faces.event.FacesListener, javax.faces.event.ValueChangeListener, javax.faces.view.facelets.FaceletHandler

public class ValidateUniqueColumn
extends javax.faces.view.facelets.TagHandler
implements javax.faces.event.ValueChangeListener

ValidateUniqueColumn validates if the given UIInput component in an UIData component has an unique value throughout all rows, also those not visible by pagination. This validator works directly on the data model and may therefore not work as expected if the data model does not represent all available rows of the UIData component (e.g. when there's means of lazy loading).

The default message is

{0}: Please fill out an unique value for the entire column. Duplicate found in row {1}

Usage example:

 <h:dataTable value="#{bean.items}" var="item">
   <h:column>
     <h:inputText value="#{item.value}">
       <o:validateUniqueColumn />
     </h:inputText>
   </h:column>
 </h:dataTable>
 

In an invalidating case, only the first row on which the value is actually changed (i.e. the value change event has been fired on the input component in the particular row) will be marked invalid and a faces message will be added on the client ID of the input component in the particular row. The default message can be changed by the message attribute. Any "{0}" placeholder in the message will be substituted with the label of the input component. Any "{1}" placeholder in the message will be substituted with the 1-based row index of the data model. Note that this does not take pagination into account and that this needs if necessary to be taken care of in the custom message yourself.

 <o:validateUniqueColumn message="Duplicate value!" />
 

Since:

1.3

Author:

Bauke Scholtz

Field Summary

Fields inherited from class javax.faces.view.facelets.TagHandler

nextHandler, tag, tagId

Constructor Summary

ValidateUniqueColumn(javax.faces.view.facelets.TagConfig config)
The tag constructor.

Method Summary

void	apply(javax.faces.view.facelets.FaceletContext context, javax.faces.component.UIComponent parent) If the component is new, check if it's an instance of UIInput and then register this tag as a value change listener on it.
java.lang.String	getMessage() Returns the runtime evaluated value of the message attribute.
boolean	isDisabled() Returns the runtime evaluated value of the disabled attribute.
void	processValueChange(javax.faces.event.ValueChangeEvent event) When this tag is not disabled, the input value is changed, the input component is valid and the input component's local value is not null, then check for a duplicate value by visiting all rows of the parent UIData component.

Methods inherited from class javax.faces.view.facelets.TagHandler

getAttribute, getRequiredAttribute, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ValidateUniqueColumn

public ValidateUniqueColumn(javax.faces.view.facelets.TagConfig config)

The tag constructor.

Parameters:

config - The tag config.

Method Detail

apply

public void apply(javax.faces.view.facelets.FaceletContext context,
                  javax.faces.component.UIComponent parent)
           throws java.io.IOException

If the component is new, check if it's an instance of UIInput and then register this tag as a value change listener on it. If the component is not new, check if there's an UIData parent.

Specified by:

apply in interface javax.faces.view.facelets.FaceletHandler

Throws:

java.io.IOException

processValueChange

public void processValueChange(javax.faces.event.ValueChangeEvent event)
                        throws javax.faces.event.AbortProcessingException

When this tag is not disabled, the input value is changed, the input component is valid and the input component's local value is not null, then check for a duplicate value by visiting all rows of the parent UIData component.

Specified by:

processValueChange in interface javax.faces.event.ValueChangeListener

Throws:

javax.faces.event.AbortProcessingException

getMessage

public java.lang.String getMessage()

Returns the runtime evaluated value of the message attribute.

Returns:

The runtime evaluated value of the message attribute.

isDisabled

public boolean isDisabled()

Returns the runtime evaluated value of the disabled attribute.

Returns:

The runtime evaluated value of the disabled attribute.