The <form-bean> type attribute should be optional

• Key: STR-2894
• Type: Bug
• Status: Closed
• Resolution: Not A Problem
• Priority: Major
• Assignee: Unassigned
• Reporter: Wendy Smoak
• Component/s: Core
• Affects Version/s: Nightly Build
• Fix Version/s: 1.3.6

Description

According to the 1.3 DTD, the 'type' attribute of <form-bean> is optional.
   http://struts.apache.org/dtds/struts-config/1_3/

However, omitting it from the form bean definition in struts-config.xml results in an error.

        <form-bean
            name="inputForm" />

SEVERE: Servlet /my-webapp threw load() exception
javax.servlet.UnavailableException: Missing type value for inputForm form bean
at org.apache.struts.action.ActionServlet.handleValueRequiredException(ActionServlet.java:830)
at org.apache.struts.action.ActionServlet.initModuleFormBeans(ActionServlet.java:926)
at org.apache.struts.action.ActionServlet.init(ActionServlet.java:357)
at javax.servlet.GenericServlet.init(GenericServlet.java:211)

Comments

[Wendy Smoak]

s/element/attribute

[Wendy Smoak]

Attached a sample Maven 2 project based on the struts-blank archetype which demonstrates the problem.

To reproduce:
 1. extract the zip file to a temporary location,
 2. modify pom.xml <container>/<home> with the path to a local install of Tomcat 5x
 3. mvn package cargo:start
 4. CTRL-C to stop the container
 5. look at target/tomcat5x.out for the stack trace

[Wendy Smoak]

TODO: Update the sample app. It no longer builds. It was done when the groupId was org.apache.struts.action, and those artifacts have been removed from the snapshot repo.

[Paul Benedict]

Wendy,

I see the offending line in the ActionServlet on line 927 (and again on 939):

            // Verify that required fields are all present for the form config
            if (formBean.getType() == null) {
                handleValueRequiredException("type", formBean.getName(),
                    "form bean");
            }

Are you asking to delete that line?

Since the type is optional. What is the type when it is not explicilty stated?

[Wendy Smoak]

It's been so long that I don't really remember.

The main issue is that the documentation doesn't match the actual behavior. The DTD says the type attribute is optional, but you get an error if you leave it out.

[Martin Cooper]

The type attribute on <form-bean> was made optional with Hubert's 'extends' changes. It's not entirely optional insofar as every actual form bean has to have the type attribute specified. However, it's optional insofar you can omit it from any given level in the extension hierarchy, so long as it exists at least once in that hierarchy. So I believe this bug report is invalid, but someone please correct me if I'm wrong.

[Paul Benedict]

Thanks Wendy and Martin. So if both the "type" and "extends" attribute are absent, throw the error? That's a good business rule.

[Wendy Smoak]

Resolving as invalid. Thanks to Martin for the explanation.

[Martin Cooper]

Not quite, Paul. I could define a "base" form bean that has neither, such that a later 'extends' form bean adds the 'type' attribute. The rule would have to be that every concrete form bean - those actually referenced / used - ultimately has a type attribute provided somewhere in its definition hierarchy.