The tag allows dynamic columns functionality in a rich:dataTable. It is used like a UIData component which iterates through a data model to create columns.

The component uses a standard value/var pair of attributes to provide binding to data model and request scoped variable for iteration through this data model.

The next simple example shows you a simple use-case where ten types of cars are created and a list of models with prices is generated for each type of car. In the dataTable cars are grouped by type in a separate columns.

DataTable Columns example

Cars Available
Chevrolet	Ford	Nissan	Toyota	GMC	Infiniti
Corvette 48647.0 miles 18719$	Explorer 9269.0 miles 24923$	Maxima 77421.0 miles 38496$	Camry 75872.0 miles 46538$	Yukon 16680.0 miles 41469$	G35 51885.0 miles 52918$
Corvette 50126.0 miles 49026$	Explorer 66007.0 miles 39778$	Maxima 35144.0 miles 16829$	Camry 71875.0 miles 36705$	Yukon 27288.0 miles 22557$	G35 40813.0 miles 26724$
Corvette 25720.0 miles 27472$	Explorer 35216.0 miles 32413$	Maxima 68865.0 miles 36932$	Camry 50985.0 miles 15419$	Yukon 65522.0 miles 16939$	G35 44119.0 miles 31905$
Corvette 52232.0 miles 48615$	Explorer 16535.0 miles 31642$	Maxima 8152.0 miles 31172$	Camry 75925.0 miles 24686$	Yukon 75229.0 miles 26565$	G35 35026.0 miles 47219$
Corvette 18630.0 miles 38170$	Explorer 26390.0 miles 27515$	Maxima 37558.0 miles 27399$	Camry 41616.0 miles 48147$	Yukon 6295.0 miles 41588$	G35 76335.0 miles 44610$
Corvette 44019.0 miles 40688$	Explorer 36259.0 miles 46290$	Maxima 8920.0 miles 20182$	Camry 65039.0 miles 45919$	Yukon 64654.0 miles 40132$	G35 52915.0 miles 36162$
Corvette 49788.0 miles 48864$	Explorer 43744.0 miles 27140$	Maxima 17458.0 miles 41164$	Camry 67672.0 miles 47748$	Yukon 30787.0 miles 52221$	G35 77647.0 miles 22469$
Corvette 74086.0 miles 40492$	Explorer 11905.0 miles 37712$	Maxima 18342.0 miles 40371$	Camry 50326.0 miles 48895$	Yukon 32167.0 miles 49787$	G35 79960.0 miles 25661$
Corvette 52577.0 miles 38302$	Explorer 5824.0 miles 17134$	Maxima 50464.0 miles 38610$	Camry 67646.0 miles 54880$	Yukon 5807.0 miles 15359$	G35 45511.0 miles 35140$

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<ui:composition xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:a4j="http://richfaces.org/a4j"
    xmlns:rich="http://richfaces.org/rich">
    <h:form>
        <rich:dataTable value="#{dataTableScrollerBean.model}" var="model" width="750">

            <f:facet name="header">
                <h:outputText value="Cars Available"></h:outputText>
            </f:facet>
            
            <rich:columns value="#{dataTableScrollerBean.columns}" var="columns"
                index="ind" id="column#{ind}" sortBy="#{model[ind].price}" sortOrder="#{columns.sortOrder}">
                 
                <f:facet name="header">
                    <h:outputText value="#{columns.header}" />
                </f:facet>
            
                <h:outputText value="#{model[ind].model} " />
                <h:outputText value="#{model[ind].mileage} miles " />
                <h:outputText value="#{model[ind].price}$"
                    style="font-style:italic;" />
                    
            </rich:columns>
            
        </rich:dataTable>
    </h:form>
</ui:composition>

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