Cryptic Error Messages

[Mat Jaggard]

I'm finding the error messages produced by Cambridge to be
particularly unhelpful.

In my particular case, I got the error "Error parsing expression: $
{user.userId}"
but it turned out that the problem was with a:else...

This works...
<option value="${user.userId}" a:else >

this fails...
<option a:else value="${user.userId}">

It's not just that this seems to be a bug (correct me if I'm wrong but
I can't find it in the documentation) - the error reporting generally
isn't good and so it took me ages to work out why the expressions I
was using didn't work. I thought it was because of my use of a
Map.Entry. Even just printing which line of ExpressionParser caused
the problem would help. The stack trace printing at the moment doesn't
actually show where the problem is.

[Erdinc Yilmazel]

Hi Mat,

I appreciate if you can send me a template file (a snippet) that causes this error and I will look at it.
I will be on vacation next week, but when I come back I am going to start spending a lot of time on this project.
I have been very busy in past 3 months with something else but now it is over and I will focus my energy to
enhancing developer experience, documentation etc.

Erdinc

[Matthew Jaggard]

Cool, thank you very much.

My template is this...

<!--$extends skeleton.html-->

<div id="bodyarea">

<h1>${actionName} an Index</h1>

<div a:if="error">${error}</div>

<form action="${base_url}${action}" method="POST">

Name:<br/>

<input a:if="edit" autofocus="autofocus" type="text" name="${action}" value="${indexName}" readonly="readonly" />

<input a:else autofocus="autofocus" type="text" name="${action}" value="${indexName}" /><br/>

<h2>Access</h2>

<label for="${allowed_users_param}">Allowed Users:</label><br/>

<span a:if="edit">(you are automatically allowed access)</span>

<select multiple="multiple" size="${size}" name="${allowed_users_param}">

<a:span a:foreach="userDetails.keySet()" a:as="user">

<option a:if="userDetails[user]" value="${user.userId}" selected="selected">${user.nickname}</option>

<option value="${user.userId}" a:else >${user.nickname}</option>

</a:span>

</select><br/>

<small>Admin users are always allowed access</small><br/>

<input a:foreach="usersUsedToBeAllowed" a:as="user" type="hidden" value="${user}" />

<input a:if="edit" type="submit" value="Update"/>

<input a:else type="submit" value="Create"/>

</form>

</div>

and my template contains quite a lot of fields but the relevant one is a Map<User,Boolean> to say if the user is allowed access to the item in question.

It's actually all working now, but it stops working with the error I gave if I swap the attributes a:each and value="${user.userId}"

Many thanks,

Mat.

[Matthew Jaggard]

I've also just noticed that these lines...

<input a:if="edit" type="submit" value="Update"/>

<input a:else type="submit" value="Create"/>

Are producing this output...

<input value="Create" />

Thanks,

Mat.

[Erdinc Yilmazel]

Can you make it print the value of edit and have a look?

You can either put ${edit} somewhere on the page or put <!--$debug --> somewhere.

Erdinc

[Matthew Jaggard]

Sure. It's false...

java.lang.Boolean edit false

Thanks,

Mat.

[Matthew Jaggard]

Also, I tried to iterate through a Map using the entrySet

a:foreach="myMap.entrySet" a:as="entry"

then

${entry.key}

but I got an error about not being able to access public final fields. Why can't I access public final fields?

(By the way, I have already fixed this by using keySet instead of entrySet and then myMap[key] to get the value)

Thanks,

Mat.

[Jeff Schnitzer]

Matt, you might find it easier to use JEXL as the expression language.  That's what Jon and I use now after tying several of the others, and it helps a lot.  Full method calls, you can pass parameters, etc.

Jeff

[Erdinc Yilmazel]

Matt which version are you using? Can you try building the latest from trunk? I've tried all these now using the latest code and could not reproduce it. I will update the downloadable package soon.

Thanks,

Erdinc