Re: [Pharo-users] GLMFormatedPresentation>>format bug?

May 16, 2016

      On Mon, May 16, 2016 at 05:42:54AM +0200, Tudor Girba wrote:
...
Hi,
On May 16, 2016, at 1:00 AM, Ben Coman <btc@openInWorld.com> wrote:
On Mon, May 16, 2016 at 6:28 AM, Alistair Grant <akgrant0710@gmail.com>
    wrote:
Hi Andrei,
On Mon, May 16, 2016 at 12:08:01AM +0200, Andrei Chis wrote:
Hi Alistair,
Try something like this. Now 100% sure it will work.
gtInspectIn: composite
                   <gtInspectorPresentationOrder: 30>
^ composite text
                           title: 'Meme';
                           format: [self asText].
The display block should return the object to be displayed, which
            is this case
            is self.
Yep, that fixes the problem!  Thanks for your reply.
Just curious if this also works...
^ composite text
                    title: 'Meme';
                    format: #asText
This also works, and looking at the definition of #format I'm guessing
that this is closer to the original intended usage (see below)?
...
It works because the format block takes an optional argument with the input
entity. However, the semantics are not going to be quite the same. In
isolation, the behavior will be identical. However, the difference comes when
you try to reuse a presentation.
Letâs look at an example. This is how an AST node displays the source:
RBProgramNode>>gtInspectorSourceCodeIn: composite
<gtInspectorPresentationOrder: 30> 
^ composite pharoMethod 
title: 'Source codeâ;
display: [ self source ];
...
Like this, the block closure can simply delegate to the corresponding ast node
to display the source:
BlockClosure>>gtInspectorSourceCodeIn: composite 
<gtInspectorPresentationOrder: 40>
self sourceNode gtInspectorSourceCodeIn: composite
And a keymap object which holds a block in an action instance variable, can
simply delegate to the block closure object to display the source:
KMKeymap>>gtInspectorSourceCodeIn: composite
<gtInspectorPresentationOrder: 30> 
^ self action gtInspectorSourceCodeIn: composite
If the ProgramNode definition would have been implemented like:
display: [ :each | each source ]
then when inspecting the block object, we would have gotten the block object as
each, and not the AST node.
Does this explanation make sense?
So using this code is going to be more flexible than

    ^ composite text
        title: 'Meme';
        format: [self asText]

since the format object isn't supplied the optional arguments.

Thanks,
Alistair