From 238e0d5b7e850b1d0d15e9e3722726a3812aadc4 Mon Sep 17 00:00:00 2001
From: Tomas Cohen Arazi <tomascohen@theke.io>
Date: Mon, 11 Nov 2019 15:03:28 -0300
Subject: [PATCH] Bug 23893: Implement Koha::Object->from_api_mapping

This patch implements the from_api_mapping method, that calculates (and
caches) the reserve mapping from the to_api_mapping method.

A generic to_api_mapping is added to simplify things a bit in the generic
to_api method and so the mappings are reusable in the way they are in
from_api_mapping.

To test:
1. Apply this patches
2. Run:
  $ kshell
 k$ prove t/db_dependent/Koha/Object.t
=> SUCCESS: Tests pass!
3. Sign off :-D
---
 Koha/Object.pm | 102 +++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 87 insertions(+), 15 deletions(-)

diff --git a/Koha/Object.pm b/Koha/Object.pm
index 108ea2e52f..92ac58ccac 100644
--- a/Koha/Object.pm
+++ b/Koha/Object.pm
@@ -368,28 +368,68 @@ sub to_api {
     my ( $self ) = @_;
     my $json_object = $self->TO_JSON;
 
+    my $to_api_mapping = $self->to_api_mapping;
+
     # Rename attributes if there's a mapping
-    if ( $self->can('to_api_mapping') ) {
-        foreach my $column ( keys %{$self->to_api_mapping} ) {
-            my $mapped_column = $self->to_api_mapping->{$column};
-            if ( exists $json_object->{$column}
-                && defined $mapped_column )
-            {
-                # key != undef
-                $json_object->{$mapped_column} = delete $json_object->{$column};
-            }
-            elsif ( exists $json_object->{$column}
-                && !defined $mapped_column )
-            {
-                # key == undef
-                delete $json_object->{$column};
-            }
+    foreach my $column ( keys %{$to_api_mapping} ) {
+        my $mapped_column = $to_api_mapping->{$column};
+        if ( exists $json_object->{$column}
+            && defined $mapped_column )
+        {
+            # key != undef
+            $json_object->{$mapped_column} = delete $json_object->{$column};
+        }
+        elsif ( exists $json_object->{$column}
+            && !defined $mapped_column )
+        {
+            # key == undef
+            delete $json_object->{$column};
         }
     }
 
     return $json_object;
 }
 
+=head3 to_api_mapping
+
+    my $mapping = $object->to_api_mapping;
+
+Generic method that returns the attribute name mappings required to
+render the object on the API.
+
+Note: this only returns an empty I<hashref>. Each class should have its
+own mapping returned.
+
+=cut
+
+sub to_api_mapping {
+    return {};
+}
+
+=head3 from_api_mapping
+
+    my $mapping = $object->from_api_mapping;
+
+Generic method that returns the attribute name mappings so the data that
+comes from the API is correctly renamed to match what is required for the DB.
+
+=cut
+
+sub from_api_mapping {
+    my ( $self ) = @_;
+
+    my $to_api_mapping = $self->to_api_mapping;
+
+    unless ( $self->{_from_api_mapping} ) {
+        while (my ($key, $value) = each %{ $to_api_mapping } ) {
+            $self->{_from_api_mapping}->{$value} = $key
+                if defined $value;
+        }
+    }
+
+    return $self->{_from_api_mapping};
+}
+
 =head3 $object->unblessed_all_relateds
 
 my $everything_into_one_hashref = $object->unblessed_all_relateds
@@ -502,6 +542,38 @@ sub AUTOLOAD {
     return $r;
 }
 
+=head3 attributes_from_api
+
+    my $attributes = attributes_from_api( $params );
+
+Returns the passed params, converted from API naming into the model.
+
+=cut
+
+sub attributes_from_api {
+    my ( $self, $attributes ) = @_;
+
+    my $mapping = $self->from_api_mapping;
+
+    foreach my $attribute ( keys %{$mapping} ) {
+        my $mapped_attribute = $mapping->{$attribute};
+        if ( exists $attributes->{$attribute}
+            && defined $mapped_attribute )
+        {
+            # key => !undef
+            $attributes->{$mapped_attribute} = delete $attributes->{$attribute};
+        }
+        elsif ( exists $attributes->{$attribute}
+            && !defined $mapped_attribute )
+        {
+            # key => undef / to be deleted
+            delete $attributes->{$attribute};
+        }
+    }
+
+    return $attributes;
+}
+
 =head3 _type
 
 This method must be defined in the child class. The value is the name of the DBIC resultset.
-- 
2.24.0