spec(relations): manyToMany materialises the intermediate entity - #19
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delchev wants to merge 1 commit into
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spec(relations): manyToMany materialises the intermediate entity#19delchev wants to merge 1 commit into
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An n:m has always been an intermediate (link) entity in this specification; the kind that named it was parsed and then materialised by nothing, which is the worst of the three possible states - a clean parse and a relationship that simply is not there. Specify the materialisation: `kind: manyToMany` writes the link entity <Declaring><Target> (or the relation's `through:`) with a generated key, a composition to the declaring side and a manyToOne to the target (cross-model allowed), and the authored relation becomes the navigation-only oneToMany to it - so the document holds exactly one representation of an n:m. The link is a real entity: table, detail grid with a dropdown, seedable, reportable. The explicit intermediate entity keeps its place, and gains a clear boundary: it is how a link that carries data of its own (a quantity, a partial amount, a valid-from) is authored. Also specified: one-sided declaration, which relation attributes travel to the link's target end and which are refused rather than ignored, the through:/name-collision rules, and the self-referencing case.
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What
kind: manyToManywas parsed and materialised by nothing — a clean parse and a relationship that is simply absent from the generated application. This specifies the materialisation instead of the silent drop.An n:m has always been an intermediate (link) entity in this spec. Now the kind that names it writes that entity:
<Declaring><Target>— or the name given by the newthrough:attribute — with a generated integer key, acompositionto the declaring side and amanyToOneto the target (cross-model allowed viamodel:);oneToManyto the link, so the document holds exactly one representation of an n:m;The explicit intermediate entity keeps its place and gains a clear boundary: it is how a link that carries data of its own (a quantity, a partial amount, a valid-from date) is authored — then the
manyToManyis dropped.Also specified: declare an n:m on one side only; which relation attributes travel onto the link's target end (
where/show/major/size/leafOnly) and which are refused rather than ignored (composition,function,init,dependsOn, calculated actions,personal,partner);through:validity and the name-collision rule; the self-referencing case.Pages
docs/spec/relations.md— the Many-to-many section rewritten (materialised link + explicit intermediate entity).docs/reference.md— "Planned" entry replaced: what remains unimplemented is bridge fields on a generated link, not the kind itself;through:added to the attribute examples.