I was faced with a situation where it was necessary for me to allow a user to select multiple options from a rather large list of about 300 items. For an advanced user, a SelectManyListbox would have been an acceptable way to go. My target audience was unsophisticated, so the easiest input method for them was to use a SelectManyCheckbox input component. Sounds easy but, no, ADF Faces doesn't make things that easy.
The ADF Faces SelectManyCheckbox has the limitation of rendering its children either in one huge long vertical list or one huge long horizontal list. Either one is unattractive when you're dealing with more than just a few choices. What about a grid option? Well, the stock ADF Faces library doesn't give you that ability.
Apache MyFaces Trinidad, the freely available JSF framework and successor to ADF, has some flexible components, but I wasn't ready to replace a working framework with something completely unknown to me. Fortunately there was another option:
Apache MyFaces Tomahawk, an add-on components library compatible with MyFaces and, luckily for me, ADF Faces.
Tomahawk contains a
SelectManyCheckbox component that extends the original. Several new attributes control the number of rows or columns to use when rendering the HTML controls, exactly what I needed for the new page of my project. Lucas Jellema, in his AMIS Technology Blog, has a similar article,
Integrating ADF Faces and MyFaces Tomahawk - Creating a Popup with ADF Faces Shuttle Component, but using a different component and JSPX pages.
I followed very nearly the same integration steps, but mine differ slightly because of the JDeveloper and library versions I am using. For JDeveloper 10.1.3.3 and Tomahawk 1.1.8, here are the steps to installing and using the Tomahawk library:
1. Download the Tomahawk library. Use the
Download Tomahawk link at the top of the page for the list of available packages. Select the regular Tomahawk (for JSF 1.1); it's really for JSF 1.2. Don't use link for JSF 1.2, as is actually for JSF 2.1 and won't work with JDeveloper.
2. Download the Apache Commons FileUpload library. Confusingly, the dependency information says Tomahawk is not dependent on any other project, but this refers to
building, not
using. The FileUpload library is required.
3. Extract the archived library files to your development libaries area. I used an Apache folder.
4. In JDeveloper, add the libraries and tag libraries. a. From the JDeveloper menu, select
Tools > Manage Libraries... option.
b. From the Libraries tab, press the
New... button and add the main Tomahawk JAR file to the Class Path entry and JavaDoc and TLD Doc JAR files to the Doc Path entry. Put it into the User location.
c. From the Libraries tab, press the
New... button and add the main Commons FileUpload JAR file to the Class Path entry, the Sources JAR file to the Source Path entry, and the JavaDoc file to the Doc Path entry.
d. From the JSP Tag Libraries tab, press the
New button and select the main Tomahawk JAR file. The TLD file inside it will be automatically selected. The conventional prefix for use in your JSP source files is
t (but you can name it what you want). Select the Execute Tags in JSP Visual Editor to integrate the library into JDeveloper's visual JSP editor. It doesn't render tags in the editor correctly, but will mess up viewing all your other pages if you don't select this option.
5. Optionally, configure the required MyFaces Extensions filter in your ViewController project WEB-INF/web.xml file. I added the following sections to mine, but eventually removed them so JDeveloper would render design views correctly. For some unexplained reason, adding this configuration will cause JDeveloper's design-time renderer to hemorrhage a pile of exceptions and prevent the design views from being displayed properly. You can get a little more detail in Oracle's
JDeveloper forum.
<filter>
<filter-name>MyFacesExtensionsFilter</filter-name>
<display-name>Apache Tomahawk Filter</display-name>
<description>Set the size limit for uploaded files.
Format: 10 - 10 bytes
10k - 10 KB
10m - 10 MB
1g - 1 GB
</description>
<filter-class>org.apache.myfaces.webapp.filter.ExtensionsFilter</filter-class>
</filter>
and
<filter-mapping>
<filter-name>MyFacesExtensionsFilter</filter-name>
<servlet-name>Faces Servlet</servlet-name>
</filter-mapping>
<filter-mapping>
<filter-name>MyFacesExtensionsFilter</filter-name>
<url-pattern>/faces/myFacesExtensionsResource/*</url-pattern>
</filter-mapping>
6. Add the taglib directive for the Tomahawk Tag Library to the top of your JSP page. You can do this manually by dropping the taglib component from the JSP component palette or JDeveloper will add it for you when you drop the first Tomahawk component on the page.
7. In your ViewController project Project Properties page, add the new libraries. Add the Tomahawk and Commons FileUpload libraries to the Libraries list and the Tomahawk tag library to the JSP Tag Libraries list.
8. Check your ViewController project WAR deployment profile. Make sure the necessary libraries are included in the
WEB-INF/lib directory.
Now you should be able to use the Tomahawk components on your JSP pages. They may not render correctly in the visual JSP editor, but when running your web application, they should be fine.
