Re: FYI: background to Magritte with pragma support

FYI ---------- Forwarded message ---------- From: Lukas Renggli &lt;renggli(a)gmail.com&gt; Date: 17 November 2010 17:21 Subject: Re: Providing lookup environment for descriptions To: "Magritte, Pier and Related Tools ..." &lt;smallwiki(a)iam.unibe.ch&gt; The way Magritte builds descriptions by default has become quite a nuisance. Of course you can always do your own thing as Yanni describes, but I think that at some point Magritte should be improved in that regard. I wrote a proposal this summer of want to proceed on that, but of course I had to finish my writing and never actually found the time to implement it: -------------------- I propose to perform the following (non-backward compatible) changes in the Magritte 2 code-base to resolve some major annoyances and issues that keep on reoccurring: - Move descriptions from class-side to instance-side. This resolves various issues such as cache-invalidation, instance specific descriptions, dynamic descriptions, context dependent descriptions, etc. Furthermore the descriptions will be closer to the code they describe and it will be possible to describe class- and instance-side of an object, not just the instance-side. - Rename the method #description as the default entry point into Magritte to #magritteDescription. This avoids common problems where the domain model already defines such a method. - Instead of using a naming convention for description methods, use a pragma called <magritte> to annotate the methods. And to extend and change existing descriptions use <magritte: aSelector>. Finally all Smalltalk implementation reached a consensus of pragmas that can be safely used cross-platform. All in all the "new" Magritte would look like in the following example. Imagine a shop item with the accessor #place: Item>>place ^ place Item>>place: aString place := aString The meta-description is defined on the instance-side and annotated. It can refer to itself for the possible places: Item>>placeDescription <magritte> ^ MASingleOptionDescription new options: self possiblePlaces; label: 'Place of Item'; accessor: #place; yourself Class extensions can modify a description using: Item>>placeDescriptionXmlStorage: aDescription <magritte: #placeDescription> ^ placeDescription xmlTag: 'xname' Since these changes are not backward compatible I'll try to provide automatic refactorings for most parts. Moving existing code to the new codebase will certainly cause some problems, but in the long run I believe this to be a much better approach than the current one. If people have any feedback, concerns or other changes that would be important in the same run I am happy to hear them. -------------------- _______________________________________________ Magritte, Pier and Related Tools ... https://www.iam.unibe.ch/mailman/listinfo/smallwiki