Converting Between Model and View Data Formats
Adding the value binding expression
takes us one step
closer to a real application, but we’re not done
yet. First, note that the date fields are too short to show the dates
in the format in which they are presented. Also, if you try to submit
the form, error messages regarding the dates are displayed at the top
of the page. The error messages are displayed by the
<h:messages>
action I added at the top in
Example 6-3, which I’ll get back to
in the next chapter.
The reason for the error messages is that the value is sent to the
application as a string (an HTTP request parameter is always a
string), but the data type for the from
and
to
properties is
java.util.Date
. JSF takes care of conversion
between strings and simple data types—numbers and
Booleans—all by itself, but a date can be written in many
different ways, so we need to give JSF a clue about how to interpret
a string representing a date. Example 6-4 shows you
how this is done.
<%@ page contentType="text/html" %> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %> <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %> <f:view> <h:messages layout="table"/> <h:form> From: <h:inputText size="8" value="#{reportHandler.from}"><f:convertDateTime dateStyle="short" />
</h:inputText> <br> To: <h:inputText size="8" value="#{reportHandler.to}"><f:convertDateTime dateStyle="short" />
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