How to set converter properties for each row/item of h:dataTable/ui:repeat?

Question

To the point, you expected that the converter’s properties are set every time a datatable row is rendered. This is indeed not true. JSF will create only one converter instance per component when the view is to be built, it will not create/reset the converter each time the row is rendered.

There are several ways to get it to work.

Pass the dynamic attributes as <f:attribute> of the component and let the Converter intercept on that. You can find an example here: JSF convertDateTime with timezone in datatable. This can then be used as
```
<h:outputText value="#{item.balanceDate}">
    <f:converter converterId="isoDateTimeConverter" />
    <f:attribute name="pattern" value="#{item.pattern}" />
</h:outputText>
```
Use an EL function instead of a Converter. You can find an example here: Facelets and JSTL (Converting a Date to a String for use in a field). This can then be used as
```
<h:outputText value="#{mh:convertIsoDate(item.balanceDate, item.pattern)}" />
```

Bind the converter and datatable’s DataModel as a property of the same managed bean. This way you will be able to set the converter’s properties based on the row data before returning it. Here’s a basic kickoff example based on standard JSF components and standard DateTimeConverter (it should work equally good on PrimeFaces components and with your custom converter):

<h:dataTable value="#{bean.model}" var="item">
    <h:column>
        <h:outputText value="#{item.date}" converter="#{bean.converter}" />
    </h:column>
</h:dataTable>

with

@ManagedBean
@ViewScoped
public class Bean implements Serializable {

    private List<Item> items;
    private DataModel<Item> model;
    private DateTimeConverter converter;

    @PostConstruct
    public void init() {
        items = Arrays.asList(
            new Item(new Date(), "dd-MM-yyyy"), 
            new Item(new Date(), "yyyy-MM-dd"), 
            new Item(new Date(), "MM/dd/yyyy"));
        model = new ListDataModel<Item>(items);
        converter = new DateTimeConverter();
    }

    public DataModel<Item> getModel() {
        return model;
    }

    public Converter getConverter() {
        converter.setPattern(model.getRowData().getPattern());
        return converter;
    }

}

(the Item class is just a bean with two properties Date date and String pattern)

this results in

23-09-2011
2011-09-23
09/23/2011

Use OmniFaces <o:converter> instead. It supports render time evaluation of EL in the attributes. See also the <o:converter> showcase example.

<h:outputText value="#{item.balanceDate}">
    <o:converter converterId="isoDateTimeConverter" pattern="#{item.pattern}" />
</h:outputText>

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