https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=43663
Bug ID: 43663
Summary: Add Koha::Objects::Mixin::Polymorphic for polymorphic
subclass dispatch
Initiative type: ---
Sponsorship ---
status:
Product: Koha
Version: Main
Hardware: All
OS: All
Status: NEW
Severity: enhancement
Priority: P5 - low
Component: Architecture, internals, and plumbing
Assignee: [email protected]
Reporter: [email protected]
QA Contact: [email protected]
Target Milestone: ---
Several Koha::Objects plural classes independently implement the same
pattern: given a row, decide which Koha::Object subclass should
represent it, based on the value of one column (a hand-rolled
_polymorphic_field/_polymorphic_map pair plus an ~8-line object_class
method).
Koha::File::Transports (already in main) dispatches on the 'transport'
column to Koha::File::Transport::{SFTP,FTP,Local}.
Koha::Auth::Identity::Providers
(bug 24880, not yet merged) dispatches on 'protocol' to
Koha::Auth::Identity::Provider::{OAuth,OIDC,SAML2}. The same need came
up again during review of bug 42870 (pluggable email transports).
Koha::Auth::Identity::Provider::OAuth additionally hand-types its own
dispatch key a second time, independently, inside its own new()
($params->{protocol} = 'OAuth';) - nothing ties that string to the
_polymorphic_map entry in the plural class that has to match it, so
the two can silently drift apart.
This bug extracts the shared behaviour into a proper
Koha::Objects::Mixin::* (the same convention Koha already uses for
Koha::Objects::Mixin::AdditionalFields, composed via 'use parent qw(
Koha::Objects Koha::Objects::Mixin::Foo )', used by 20+ plural
classes), and migrates the one already-in-main consumer
(Koha::File::Transports) onto it as proof it is behaviour-preserving.
A consuming plural class declares:
sub _polymorphic_field { return 'transport' }
sub _polymorphic_classes { return (List::Of::Class::Names) }
sub _polymorphic_base_class { return 'Fallback::Class::Name' }
Each subclass self-declares its own dispatch key:
sub _polymorphic_key { return 'sftp' }
The mixin builds _polymorphic_map from _polymorphic_classes plus each
class's own _polymorphic_key, and provides object_class() itself, so
the copy-pasted dispatch logic disappears from every consumer, not
just the map. A plural class needing genuinely custom mapping logic
can still override _polymorphic_map (or object_class) directly -
ordinary Perl inheritance makes that a free escape hatch.
This is a proposal filed ahead of code, based on a design worked out
with the QA team. It is deliberately narrow: it introduces no
mechanism for Koha Plugins to register additional polymorphic
subclasses, no Plugin management UI changes, and no koha-conf.xml
changes - that is a separate, later concern once a concrete capability
needs it. It does not touch Koha::Auth::Identity::Providers (bug
24880) or bug 42870 directly; both could adopt this mixin as a
follow-up once merged.
Patches to follow.
Test plan (once patches are attached):
1. Apply the patch(es).
2. Run prove t/db_dependent/Koha/Objects/Mixin/Polymorphic.t and
confirm all tests pass.
3. Run prove t/db_dependent/Koha/File/Transport.t
t/db_dependent/Koha/File/Transports.t
t/db_dependent/Koha/File/Transport/FTP.t
t/db_dependent/Koha/File/Transport/Local.t
t/db_dependent/Koha/File/Transport/SFTP.t
and confirm they all still pass unmodified against the migrated
Koha::File::Transports, proving the migration is behaviour-preserving.
--
You are receiving this mail because:
You are the assignee for the bug.
You are watching all bug changes.
_______________________________________________
Koha-bugs mailing list -- [email protected]
To unsubscribe send an email to [email protected]
website : http://www.koha-community.org/
git : http://git.koha-community.org/
bugs : http://bugs.koha-community.org/
