HibernateRelationshipsUI

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About this Tutorial

• Edit a User and their Weblogs (many-to-many)
• CRUD a Weblog and its Users (many-to-many)
• CRUD a Weblog and its Entries (one-to-many)
• Add a Category drop-down for Entries (many-to-one)

Table of Contents

• [1] Modify userForm.jsp to allow creating/editing a weblog (many-to-many)
• [2] Modify the UserAction to support editing a user's weblogs
• [3] Create a WeblogAction to handle CRUD-ing Weblogs
• [4] Create JSPs to display a Weblog's information
• [5] Add the ability to edit users from the Weblog Detail Screen
• [6] Add the ability to edit entries from the Weblog Detail Screen

Modify userForm.jsp to allow creating/editing a weblog [#1]

A weblog record has 3 fields: weblogId, blogTitle and dateCreated. The blogTitle is the only field that users should be able to edit. The rest of them can be set programmatically. Open web/pages/userForm.jsp and add the following code to the bottom of the form (between </table> and </form>.

<fieldset style="position: absolute; top: 190px; left: 520px">
    <legend style="font-weight: bold">Weblogs</legend>
    <c:forEach var="blog" items="${userForm.weblogs}" varStatus="index">
        <input type="hidden" name="weblogs[<c:out value='${index.index}'/>].weblogId" value="<c:out value='${blog.weblogId}'/>"/>
        <input type="hidden" name="weblogs[<c:out value='${index.index}'/>].dateCreated" value="<fmt:formatDate value='${blog.dateCreated}' pattern="MM/dd/yyyy"/>"/>
        <input type="text" name="weblogs[<c:out value='${index.index}'/>].blogTitle" size="40" value="<c:out value='${blog.blogTitle}'/>"/><br/>
    </c:forEach>
</fieldset>

Run ant clean deploy, go to http://localhost:8080/appfuse/editProfile.html and login as "tomcat/tomcat". You should see a screenshot like the one below.

If you try to save at this point, you'll probably get the following error:

The process did not complete. Details should follow.
IllegalArgumentException occurred calling getter of org.appfuse.model.Weblog.weblogId
object is not an instance of declaring class

This happens because the "weblogs" property of User is populated with a bunch of WeblogForm objects, instead of Weblog objects.

Modify the UserAction to support editing a user's weblogs [#2]

To fix saving a User, add convertLists(user) to the save() method of UserAction.java (in src/web/**/webapp/action):

In addition, you can add convertLists(user) to UserAction.edit():

NOTE: The reason convertLists(Object) isn't called automatically by the convert(Object) method is because it invokes lazy-loaded collections. APF-81

This will allow you to get rid of the <fmt:formatDate> tag around the dateCreated property.

<input type="hidden" name="weblogs[<c:out value='${index.index}'/>].dateCreated" value="<c:out value='${blog.dateCreated}'/>"/>

Run ant deploy, wait for Tomcat to reload your application, and then try saving the User Profile again. This time it should succeed - and you can also change the blog title if you so choose.

Create a WeblogAction to handle CRUD-ing Weblogs [#3]

In order to edit a Weblog object, and it's children (Users and Entries), you need to create a WeblogAction.java class. Before you do that, you'll need to add a couple constants to src/dao/**/Constants.java:

Then download WeblogAction.java and put it in your src/web/**/webapp/action directory. This class already has the convertLists(Object) methods that you added to UserAction.java.

Create JSPs to display a Weblog's information [#4]

Add the following i18n keys to web/WEB-INF/classes/ApplicationResources.properties. You'll need these for the master/detail screen when editing weblogs.

# -- weblog form --
weblogForm.weblogId=Weblog Id
weblogForm.blogTitle=Blog Title
weblogForm.dateCreated=Date Created
weblogForm.entries=Entries
weblogForm.users=Users

weblog.added=Weblog has been added successfully.
weblog.updated=Weblog has been updated successfully.
weblog.deleted=Weblog has been deleted successfully.

# -- weblog list page --
weblogList.title=Weblog List
weblogList.heading=Weblogs

# -- weblog detail page --
weblogDetail.title=Weblog Detail
weblogDetail.heading=Weblog Information

Create weblogList.jsp and weblogForm.jsp files in web/pages.

Add a "WeblogMenu" to web/WEB-INF/menu-config.xml:

<Menu name="WeblogMenu" title="weblogList.title" page="/weblogs.html"/>

Add this menu to web/pages/menu.jsp:

...
    <menu:displayMenu name="WeblogMenu"/>
</menu:useMenuDisplayer>

There is an issue with Struts where the client-side validation blows up if you have <html:javascript> tags in your page and no validation rules defined. To prevent this from happening, add at least validation rule to Weblog.java. For example, that blogTitle is a required field.

At this point, you should be able to run ant deploy reload and navigate to the "Weblog List" (from the menu). You should also be able to perform CRUD on a weblog object.

NOTE: If you get a "invalid LOC header (bad signature)" error, you'll need to stop/start Tomcat to get rid of it. To prevent it from happening in the future, you'll need to patch build.xml and metadata/web/web-settings.xml (APF-123).

Add the ability to edit users from the Weblog Detail Screen [#5]

1. Change Weblog.users to List from Set
2. Make WeblogDAO Transactional by moving bean definition to -service.xml and wrapping it with a txProxy
3. Add logic to WeblogAction to update User's Roles
4. Insert record into database to show 2 users: insert into weblog_user values ('mraible', 1);
5. add class="tallCell" to pretty up view of users

Add the ability to edit entries from the Weblog Detail Screen [#6]

1. Add block of code to show entries
2. Uncomment entries block in Weblog.java
3. Modify struts_form.xdt so collections ending with "ies" will get their POJO's names ending with "y" (i.e. entries -> Entry).
4. TODO: Figure out how to get DateConverter and TimestampConverter to play nicely with each other (maybe combine them)
5. Style up the "posted at" text

1. Add AVAILABLE_CATEGORIES to Constants.java
2. Grab Categories in StartupListener and expose them, discuss why not do it in edit() method
3. Add "extends Manager" to LookupManager interface so getObjects() can be used in StartupListener
4. LookupManager.getObjects results in NPE, change signature of setLookupDAO() method to call super.dao = dao:

1. Add html:select tag to weblogForm.jsp, include prettying up - show screenshot
2. POSSIBLITY: Add "title" to Entry.java

Add the ability to delete an entry

1. Wrap nested:iterate with div id

1. This will delete, but only the first one - might need some more JavaScript magic to shuffle the numbers
2. Delete only works if last entry is deleted
3. Add only works if there's already an existing one to replicate.

WeblogWithUsers.png		12462 bytes
WeblogAction.java		5803 bytes
weblogList.jsp		1483 bytes
WeblogWithEntry.png		14386 bytes
WeblogCRUD.png		38859 bytes
UserWithWeblog.png		10692 bytes
weblogForm.jsp		1782 bytes
WeblogWithCategory.png		15572 bytes