[Seaside-dev] Seaside's use of class-side #initialize

[Tobias Pape]

Hi,

On 27.01.2015, at 18:13, John O'Keefe <wembley at instantiations.com> wrote:

> I'm trying to work through an anomaly in our VA Smalltalk Seaside implementation and it seems to boil down to a difference between Pharo and VA Smalltalk in when the class-side #initialize methods are run.
>  * On Pharo, they are only run if the source for the #initialize method that is being loaded does not match the source of the #initialize method that was previously loaded (which is, of course, nil if the method does not already exist in the image)

This seems correct to me.

>  * On VA Smalltalk, they are always run when an Application is loaded

What is the semantics of "an Application is loaded"?

Best
	-Tobias

> 
> Pharo's approach seems designed for #initialize methods with simple setter methods (like classVarA := 7). However, since the 'source code matching' doesn't recursively match the source code of methods being called from #initialize, nor is there any guarantee that called methods will always return the same thing even if their source hasn't changed, this seems like a flawed optimization to me (at least when complex #initialize methods are involved). But since it is what Pharo provides, I guess it is what you use.
> 
> I also see this sort of code in several methods called from #initialize:
> 
>  configureApplicationDefaults
>     (configuredApplicationDefaults ifNil: [ false ]) ifFalse: [
>        WAAdmin applicationDefaults
>           at: #responseGenerator put: WAHtmlResponseGenerator.
>        configuredApplicationDefaults := true ] 
> 
> This seems to be a guard against the VA Smalltalk style of class initialization.
> 
> Can someone with a deeper understanding of the workings of Pharo than I have confirm that this is what is happening? 
> 
> Thanks, John
> 
> john_okeefe at instantiations.com
> http://www.instantiations.com
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