WAComponentsNotFoundError when working the To Do tutorial from "An Introduction to Seaside"

Hi.  I'm getting an error, and I'm not sure what to do.  I've
completed the exercises up through chapter 4.  I get the list of
tasks, and the menu bar across the top.  The problem is that, when I
click one of the links, I get "WAComponentsNotFoundError".

The system suggests these possible causes:

    * you do not implement #children correctly
    * you do not backtrack #children correctly
    * you do not implement #states correctly

I put a breakpoint in #children, and it appears to be returning the
right components.

Do I need to explicitly turn on backtracking?  I'm not familiar with
#states, was I supposed to do something with that?

I'm working with the "Developer Image" from seaside.st.  Squeak 3.9,
Seaside 2.8a1.  I did not use monticello or update any of the
packages.

Any suggestions?

    Thanks,
    Steve
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>>>>> "Steven" == Steven Greenberg <[hidden email]> writes:

Steven> I put a breakpoint in #children, and it appears to be returning the
Steven> right components.

But are they the very same components as during the render?

A common beginner mistake is to recreate child components on each access.

That's ok, as long as you hold on to those *exact* components during the
callback phase (returning them from #children), because the callback URLs have
to point into *those* objects to know what blocks to run and state to manage.

Even better is to create your child components during your first creation
during #initialize, or lazily on first access, and then keep reusing those
components on every render.

If that helps you understand the problem, great.  If not, we'll probably need
to see more code.

--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<[hidden email]> <URL:http://www.stonehenge.com/merlyn/>
Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc.
See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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Hi Randal.  Thanks for taking a look.

I *think* that they're the same.  I'm just following the example code
in the book, and create the apps only once, during #initialize.

Fileout attached.  I created category "SEG-StTutToDoApp".

Your help is greatly appreciated.

    Thanks,
    Steve

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Aha!  I solved it.  I put a semicolon in the middle of my #with:with:

So it was

Array with: blah; with: somethingelse

Silly me!

    Thanks,
    Steve



On Thu, Oct 16, 2008 at 11:29 AM, Steven Greenberg
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Try removing the semicolon after the first 'with:' in in STRootComponent>>children so it looks like this:

children
    ^ Array
        with: menuComponent
        with: listComponent

With it in, Array is sent the first message, 'with: menuComponent', which creates a new one-element array containing menuComponent. Then the second message ('with: listComponent') is sent to the Array, creating a new one-element array containing listComponent. So ultimately #children was returning just a one-element array.

Cheers,
Pete


Steven Greenberg wrote:

Hi Randal.  Thanks for taking a look.

I *think* that they're the same.  I'm just following the example code
in the book, and create the apps only once, during #initialize.

Fileout attached.  I created category "SEG-StTutToDoApp".

Your help is greatly appreciated.

    Thanks,
    Steve
  

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