[Cuis-dev] updating a TextModelMorph

[Juan Vuletich]

On 8/24/2024 5:40 PM, Mark Volkmann via Cuis-dev wrote:
> I have a class whose initialize method creates a TextModelMorph like 
> this:
>
> textModelMorph := TextModelMorph
>     textProvider: self
>     textGetter: #text
>     textSetter: #text:.
>
> It has the following additional instance methods:
>
> text
>     ^ text
>
> text: aString
>     text := aString.
>
> In addition to displaying the TextModelMorph, it displays a button.
> When the button is clicked, it does this:
>
> self text: 'test'.
>
> But the TextModelMorph does not update to show the new value.
> I thought since I changed the "model", it would update.
> I tried lots of methods in TextModelMorph, such as 
> updateActualContents, but nothing is working.
> What do I need to do to cause it to update when the value of the text 
> instance variable changes?
>
> --
> R. Mark Volkmann
> Object Computing, Inc.

Hi Mark,

I don't have access to your full example, so I can not try what I'll 
say. So take it just as a suggestion for further exploration.

You need to do `self changed: #text.`. For an example, see senders of 
#classCommentText, especially in #newClassComment:. This is the changed: 
/update: dependency mechanism in action. According to MVC and the 
Observer pattern, models don't know about views, so they can't 
communicate directly. It is views, when created, that say 'I want to be 
notified when...'.

Hope this helps,

-- 
Juan Vuletich
cuis.st
github.com/jvuletich
researchgate.net/profile/Juan-Vuletich
independent.academia.edu/JuanVuletich
patents.justia.com/inventor/juan-manuel-vuletich
linkedin.com/in/juan-vuletich-75611b3
twitter.com/JuanVuletich

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