Re^5: OO Pattern Container x Elements and Method Chaining

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Re^6: OO Pattern Container x Elements and Method Chaining by LanX (Saint) on Oct 13, 2021 at 11:42 UTC
For instance see https://atomicobject.com/resources/oo-programming/other-oo-class-relationships Association implies symmetry; both classes know each other and can message each other. A Product class object may need to know the last sale that it was involved with. We could put a pointer to a Sale class object inside the private part of Product. A Sale class object may need to know all of the Products involved with the Sale. We can put a pointer to a pointer (double pointer) in Sale that will let us store zero or more Products associated with a Sale. hence this is not uncommon `$stock->product("Book")->lastSale()->undo()` and affects both objects update a maybe better example I found is the part_of association of Apartment <-> Room A `$room` can only belong to one containing `$apartment` and has a (weakened) back-reference Like this if `$room->burns()` than `$apartment->burns()` > but I don't believe that has any bearing on method chaining. `$street->apartment("5a")->room("living")->burns()` HTH! :) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]

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Re^6: OO Pattern Container x Elements and Method Chaining
by LanX (Saint) on Oct 13, 2021 at 11:42 UTC

https://atomicobject.com/resources/oo-programming/other-oo-class-relationships

Association implies symmetry; both classes know each other and can message each other.
A Product class object may need to know the last sale that it was involved with. We could put a pointer to a Sale class object inside the private part of Product.

A Sale class object may need to know all of the Products involved with the Sale. We can put a pointer to a pointer (double pointer) in Sale that will let us store zero or more Products associated with a Sale.

hence this is not uncommon

$stock->product("Book")->lastSale()->undo()

and affects both objects

update

a maybe better example I found is the part_of association of Apartment <-> Room

A $room can only belong to one containing $apartment and has a (weakened) back-reference

Like this if $room->burns() than $apartment->burns()

> but I don't believe that has any bearing on method chaining.

$street->apartment("5a")->room("living")->burns()

HTH! :)

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

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