Continue reading »]]> One of the new features intruduced with JSF 2 is JSR-303 aka. Bean Validation. With bean validation the input’s are validated against built-in or user defined annotations, placed on the fields, methods or classes.

I’m often in the situation, where I have to validate different values in the same form, depending on what action should be executed. After a lot google’ing and researching, I’ve found the following, pretty easy solution.

Imagine, you have the following managed bean, with the two fields firstname and lastname and a bunch of actions for doing some usefull stuff. But for some obvious reasons one of the actions needs only firstname to be validated, but another action needs firstname and lastname to be validated.

For doing this, we first need the placeholder interfaces for building the two validation groups. I use validate.Both and validate.FirstnameOnly here.

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@ManagedBean

@ViewScoped

public class TestBean implements Serializable {



  @NotNull(groups = {Both.class, FirstnameOnly.class},

           message = "First name must not be empy")

  private String firstname;



  @NotNull(groups = {Both.class},

           message = "Last name must not be empy")

  private String lastname;

Now lets see how to trigger the different validation groups using different commandButtons (or commandLinks, …).
For getting things work, we just add a f:param tag to the commandButtons and assign the full qualified class name of the validation group placeholder interface (If you want more than one, just separate it by comma) to a request parameter (GROUPS in my case).

Now you simply have to attach this value to the validationGroups attribute of the f:validateBean tag.

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<h:form>

  <h:messages/>

  <h:panelGrid columns="2">

    <h:outputText value="First name"/>

    <h:inputText value="#{testBean.firstname}">

      <f:validateBean validationGroups="#{param['GROUPS']}"/>

    </h:inputText>



    <h:outputText value="Last name"/>

    <h:inputText value="#{testBean.lastname}">

      <f:validateBean validationGroups="#{param['GROUPS']}"/>

    </h:inputText>

  </h:panelGrid>



  <h:commandButton value="First and last name"

                   action="#{testBean.someAction}">

    <f:param name="GROUPS" value="validate.Both"/>

  </h:commandButton>



  <h:commandButton value="First name only"

                   action="#{testBean.someAction}">

    <f:param name="GROUPS" value="validate.FirstnameOnly"/>

  </h:commandButton>

</h:form>

If you press the first commandLink now, both fields are validated, and if you press the second, only the first name gets validated.

In simpler cases (also if the current case is really simple), where you just want to exclude some fields from validation, just use the same method for disabling the appropriate validators. This can be done by setting the disabled attribute of the f:validateBean tag using the f:param tag.

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<h:form>

  <h:messages/>

  <h:panelGrid columns="2">

    <h:outputText value="First name"/>

    <h:inputText value="#{testBean.firstname}">

      <f:validateBean />

    </h:inputText>



    <h:outputText value="Last name"/>

    <h:inputText value="#{testBean.lastname}">

      <f:validateBean disabled="#{param['FIRSTNAME_ONLY']}"/>

    </h:inputText>

  </h:panelGrid>



  <h:commandButton value="First and last name"

                   action="#{testBean.someAction}">

    <f:param name="FIRSTNAME_ONLY" value="false"/>

  </h:commandButton>



  <h:commandButton value="First name only"

                   action="#{testBean.someAction}">

    <f:param name="FIRSTNAME_ONLY" value="true"/>

  </h:commandButton>

</h:form>

Continue reading »]]> Have you ever tried to edit your jsf code using a visual designer like dreamweaver? Or do you get your html layout from a professional designer and have to “translate” it to jsf?

In the first case, most times it will be look very strange, because the designer doesn’t understand the jsf tags and so it don’t know how to display it.

If you want to create a fast jsf prototype of your html layout you can use the jsfc attribute provided by the facelets compiler. By adding this attribute to standard html tags, you can tell the compiler, in which jsf component it has to “translate” the html component.

See the following simple html example:

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<table>

  <tr>

    <td><strong>Name</strong></td>

    <td><strong>eMail</strong></td>

  </tr>

  <tr>

    <td>John Doe</td>

    <td>jon@doe.de</td>

  </tr>

</table>

You can convert this by replacing all with a h:dataTable tag, or you can use the jsfc attribute in several ways.
One way could be:

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<table>

  <tr>

    <td><b>Name</b></td>

    <td><b>eMail</b></td>

  </tr>

  <tr jsfc="ui:repeat" value="#{userListBean.users}" var="user">

    <td>#{user.name}</td>

    <td>#{user.email}</td>

  </tr>

</table>

You see, there is no jsf tag in this code. Sou you can edit this html using your favorite designer, it will simply ignore the unknown attributes.

Another way would be, telling the facelets compiler to render the table as a h:dataTable, but because of the header row, you’ll have to use the f:facet tag.

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<table jsfc="h:dataTable" value="#{userListBean.users}" var="user">

  <tr>

    <td jsfc="h:column">

      <f:facet name="header">Username</f:facet>

      #{user.name}

    </td>

    <td jsfc="h:column">

      <f:facet name="header">eMail</f:facet>

      #{user.email}

    </td>

  </tr>

</table>

So this way you still have to use jsf tags and so the visual designer can’t interpret it correctly.