Painful unit testing in struts 2

If you plan on doing unit testing and truly decoupled action classes in struts 2 I must recommend you not to use the abstract (but helpful) ActionSupport class in your class hierarchy. Why? Many reasons, here's one.

The ActionSupport class contains some hard coupling which makes unit testing outside of a struts 2 "ActionContext" impossible. Of course, you can set up an ActionContext in the tests setUp() method and you're home free, but it's a heavy and unnecessary fixture. Inheriting the ActionSupport class binds you to this solution in some cases. Amongs others, this field

private final transient TextProvider textProvider = 
    new TextProviderFactory().createInstance(getClass(), this);

is a pain.
If the ActionContext is not setup, any call to getText(...) will cause a null-pointer exception at this line

ValueStack valueStack = ActionContext.getContext().getValueStack();

for obvious reasons.

This leaves you with three options. either you build up that awful fixture and build fragile tests which all fails in groups and tests much more logic than they should. Or you avoid testing code which touches this stuff. Or you copy the ActionSupport class (watch out for the license!) and set the field to default visibility instead of private final and replace it with a mock in the unit test.

Workaround for buggy struts 2 portlet plugin

The Struts portlet plugin makes portlet development almost as smooth as web development with struts. Except that there is no server environment like tomcat in eclipse the portlet plugin makes portlet behave just as applications.

In my setups I create maven profiles for building the portlet and developing in eclipse. By adding a webapp profile with sitemesh and setting up a basic sitemesh decorator for the portlet styling can be done without deploying to the container all the time.

Now, there are a few issues with the portlet plugin. One of them turned out to risk becoming a show-stopper for struts usage in my latest project. I've been spending some free time on digging into this and here's what I have come up with.

When form urls are rendered with the portlet plugin, the plugin adds a parameters containing the namespace and action (path) that should be executed when the form is submitted. This path is constructed from a number of parameters, the portlet namespace, current portlet mode namespace and the namespace declaration on the s:form tag. Normally, a simple test form would look like

<s:form>
 <s:textfield name="value"/>
 <s:submit method="submit" />
</s:form>

which is simple and clean and what I like about struts 2! Now let's say the action is executing in namespace /test/view as declared in the viewNamespace parameter from portlet.xml. Then the portlet url will become portlet namespace + mode namespace + tag namespace which results in "/test/view" + "" + "/test/view" since the third part is by default the namespace of the current action. Of course, this will not work.

Loosing some of the clean and simple and reusability the form can be fixed to work properly by manually setting the namespace to "nothing" and thus using only the mode namespace. This form can of course never be reused for other actions, but that might be a minor problem.

<s:form namespace="/">
 <s:textfield name="value"/>
 <s:submit method="submit" />
</s:form>

If you are also using a portlet namespace, then it probably gets worse and I won't even try to go there.

Number and date formatting in struts 2

Struts 2 has excellent capabilities built-in to handle internationalization. Not only in the sense of messages printed but also in formatting values and handling conversion of the submitted string to corresponding types, and adding field errors when they cannot be converted. All based on the user locale. Hit is a feature widely used, which became very apparent when release 2.1.3 (or maybe 2.1.4) broke the conversion error handling.

I have been fiddling for a while to get this parts working right in my forms. In those cases it is not automatic. There is no way for struts to know that the double I have in my model is actually a currency value and should be formatted accordingly. The struts documentation contains a section on what I need but it never worked, and turned out (perhaps) erroneous. It has been corrected in the most recent version but I'm putting up this post since google is not your friend always, you keep hitting wrong version in the docs now and then.

My issue is I have a date and currency value in my model, of the types Calendar and Double. I need the to be displayed in local format, and properly converted when submitted. First off is the format configuration, which goes in the resource boundle, in my case messages.properties.

format.money={0,number,#0.00}
format.date={0,date,yyyy-MM-dd}

This is actually swedish formats. The dot in the money format comes out correctly as a comma (how, I have no idea). This configuration is enough to make form post conversion work as expected.

Next step is getting output to work. This is easy if printing a number with s:property like this.

<s:text name="format.money">
    <s:param name="value" value="model.price"/>
</s:text>

And there is the s:date tag for formatting dates. This can however not be used as easily in the s:input tags where they should go. To get those formats into the form.

<s:textfield name="model.observed" label="date" 
    value="%{getText('format.date',{model.observed.time})}" />
<s:textfield key="model.price" label="price"
    value="%{getText('format.money',{model.price})}" />

Do not the time addition to the model.observed Calendar value, it makes sure the Date value is exposed, since the formatting does not work with Calendar type.