Bit #30 - Displaying the current row on an af:table

You can display the current record number as you navigate an af:table by using certain information available on the table's iterator binding, namely the currentRowIndexInRange and rangeStart attributes. The current row can be calculated by the following EL expression: #{bindings.Iterator.rangeStart+bindings.Iterator.currentRowIndexInRange+1}, where Iterator is the table's bound iterator identifier. We add one because the row index is 0-based. You will need to surround the af:table with an af:panelCollection and use one of its facets - I suggest using the secondaryToolbar facet - to add an af:toolbar with an af:outputText inside it. For the current record count to be updated as you navigate the table, you will need to setup a partialTrigger on the af:outputText to the af:table. The example below shows this implementation.

Example:

<af:panelcollection ... >
<af:table id="tbl1" ... >
  </af:table>
    <f:facet name="secondaryToolbar">
      <af:toolbar id="t1">
        <af:group id="g1">
          <af:outputtext id="ot24" value="#{bindings.Employees1Iterator.rangeStart+bindings.Employees1Iterator.currentRowIndexInRange+1}/#{bindings.Employees1Iterator.estimatedRowCount} records">
                                         visible="#{bindings.Employees1Iterator.currentRow ne null}"
                                         partialTriggers="tbl1 ::qryId1"/>
        </af:group>
      </af:toolbar>
    </f:facet>
  </af:panelcollection>

Here is what the output looks like:

Context:

JSF page

Bit #19 - Downloading a file

Use an af:fileDownloadActionListener Rich Faces component to download data from the server to a client machine. Add the listener inside the component that will initiate the download, an af:commandButton for example, and specify the content type and the name of the file. Also specify a method in a backing bean that will be called to perform the download. In the backing bean method get the formated data to be saved from the model and use the supplied OutputStream to write the data.


Example:

In .jsf page:

<af:commandbutton id="buttonid"  " text="Download" ...
    <af:filedownloadactionlistener contenttype="application/octet-stream"
                method="#{backingBean.doDownload}"  filename="defaultFilename.txt"/>          
</af:commandButton>

In backing bean:

  public void doDownload(FacesContext facesContext, OutputStream outputStream) {
      // write the neccessary code to get the download data from the Model
      String data = getDownloadData();

      // save to the output stream
      try {
          OutputStreamWriter writer = new OutputStreamWriter(outputStream,"UTF-8");
           writer.write(data);
           writer.close();
          outputStream.close();
      } catch (IOException e) {
          // handle I/O exceptions
      }
  }


Context:

JSF Page
Backing Bean

Bit #17 - Using the securityContext bean in a JSF page

To acess the user's authentication information from within a JSF page, use the securityContext bean and any of its available methods. For instance, using Expression Language (EL), the following will return true/false indicating whether the user is authenticated or not: #{securityContext.authenticated}. Similarly, to determine whether the user has been assigned a specific role, use the following EL snippet #{securityContext.userInRole['SomeRole']}. It will return true if the user has been assigned the specific role.


Example:

    // in the context of a JSF page

    <af:commandLink id="login_logout" action = "#{securityContext.authenticated ? 'logout' : 'login'}" text="#{securityContext.authenticated ? 'Logout' : 'Login'}/>

    <af:commandToolbarButton id="delete"  actionListener="#{backingBean.delete}" disabled="#{securityContext.userInRole['CanDelete']==false}" text="Delete"/>


Context:

JSF Page

Bit #3 - Adding Javascript to a JSPX page

The recommended way to add scripting to your JSPX page is via the metaContainer <facet> tag. You add the metaContainer <facet> within the <af:document> tag. You can group your scripts within the metaContainer <facet> using an <af:group> tag. The actual script should be added within an <afh:script> or a <trh:script> tag. Adding Javascript to your JSPX page by directly placing a <script> tag is not recommended because it could have undesired side effects related to the proper resizing of the components in the page.

Example:

<f:facet name="metaContainer">
    <af:group>
        <afh:script source="/js/YourJsLibrary.js"/>
        <afh:script>

           function someFunction()

           {

                 …

           }

        </afh:script>

    </af:group>

</f:facet>

Context:

JSPX Page