[Pharo-users] GLMFormatedPresentation>>format bug?

Alistair Grant akgrant0710 at gmail.com
Mon May 16 01:59:37 EDT 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 at openInWorld.com> wrote:
> 
>     On Mon, May 16, 2016 at 6:28 AM, Alistair Grant <akgrant0710 at 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. 
> 
> Let’s look at an example. This is how an AST node displays the source:
> 
> RBProgramNode>>gtInspectorSourceCodeIn: composite
> <gtInspectorPresentationOrder: 30> 
> ^ composite pharoMethod 
> title: 'Source code’;
> 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




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