Question

We use bookmarkable URLs and GET methods.

We have some parameters which contains dates and are converted using the default DateTime converter.

<f:viewParam name = "parameter" value  = "#{model.parameter}" converter = "javax.faces.DateTime" />

This works flawlessly and parameters are converter to and from String

When we have to generate links (e.g., with <h:link>) to these pages we need to convert Date parameters to a correctly formatted string (as the <f:param> tag does not support a converter). The default format of Date.toString() will not be parsed by javax.faces.converter.DateTimeConverter.

I came up with the following solution but I have the feeling the it could be done more elegantly.

I defined a custom EL function convertDate

<f:param name="parameter" value="#{ func:convertDate( model.someDate, component ) }" />

with the following implementation

public static String convertDate( Date date, UIComponent uiComponent )
{
    DateTimeConverter dateTimeConverter = new DateTimeConverter();
    return dateTimeConverter.getAsString( FacesContext.getCurrentInstance(), uiComponent, date );
}

The idea is to use the default javax.faces.convert.DateTimeConverter to convert the date but I need a reference to the corresponding UIComponent.

Does the usage of #{component} make sense? Is there a better way?

Answer 1

The DateTimeConverter uses SimpleDateFormat under the covers. You might want to use it instead so that you can get rid of the #{component} argument.