Implement enhancement #42 with tests

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Yii2 Active Record Save Relations Behavior Change Log
 
+## [1.7.0] (unreleased)
+### Added
+- Enh #42: Add the ability to retrieve old relations values
+
 ## [1.6.0]
 ### Fixed
 - Bug #36: Fix an issue with HasMany relations with composite keys (thx @leandrogehlen)

README.md

@@ -282,3 +282,15 @@ The `relationKeyName` property can be used to decide how the relations data will
 Possible constants values are:
 * `SaveRelationsBehavior::RELATION_KEY_FORM_NAME` (default): the key name will be computed using the model [`formName()`](https://www.yiiframework.com/doc/api/2.0/yii-base-model#formName()-detail) method
 * `SaveRelationsBehavior::RELATION_KEY_RELATION_NAME`: the relation name as defined in the behavior declarations will be used
+
+
+Get old relations values
+------------------------
+
+To retrieve relations value prior to there most recent modification until the model is saved, you can use:
+* `getOldAttribute($name)` method: Get a named relation old value.
+* `getOldAttribute()` method: Get an array of relations index by there name with there old values.
+
+> **Notes**
+> * If a relation has not been modified yet, its initial value will be returned
+> * Only relations defined in the behavior parameters will be returned

src/SaveRelationsBehavior.php

@@ -763,4 +763,27 @@ class SaveRelationsBehavior extends Behavior
         }
         return $keyName;
     }
+
+    /**
+     * Return the old relations values.
+     * @return array
+     */
+    public function getOldRelations()
+    {
+        $oldRelations = [];
+        foreach ($this->_relations as $relationName) {
+            $oldRelations[$relationName] = $this->getOldRelation($relationName);
+        }
+        return $oldRelations;
+    }
+
+    /**
+     * Returns the old value of the named relation.
+     * @param $relationName
+     * @return mixed
+     */
+    public function getOldRelation($relationName)
+    {
+        return array_key_exists($relationName, $this->_oldRelationValue) ? $this->_oldRelationValue[$relationName] : $this->owner->{$relationName};
+    }
 }

tests/SaveRelationsBehaviorTest.php

@@ -905,4 +905,49 @@ class SaveRelationsBehaviorTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('user1', $company->users[0]->username);
         $this->assertEquals('user2', $company->users[1]->username);
     }
+
+    public function testGetOldRelations()
+    {
+        $project = Project::findOne(1);
+        $project->company = Company::findOne(2);
+        $links = [
+            ['language' => 'fr', 'name' => 'windows10', 'link' => 'https://www.microsoft.com/fr-fr/windows/features', 'link_type_id' => 2],
+            ['language' => 'en', 'name' => 'windows10', 'link' => 'https://www.microsoft.com/en-us/windows/features', 'link_type_id' => 2]
+        ];
+        $project->links = $links;
+        $oldRelations = $project->getOldRelations();
+        $this->assertArrayHasKey('company', $oldRelations);
+        $this->assertArrayHasKey('links', $oldRelations);
+        $this->assertCount(2, $oldRelations['links']);
+        $oldLinks = $project->getOldRelation('links');
+        $this->assertInternalType('array', $oldLinks);
+        $this->assertEquals($oldLinks[0]->language, 'fr');
+        $this->assertEquals($oldLinks[0]->name, 'mac_os_x');
+        $this->assertEquals($oldLinks[0]->link, 'http://www.apple.com/fr/osx/');
+        $this->assertEquals($oldLinks[0]->link_type_id, 1);
+        $this->assertEquals($oldLinks[1]->language, 'en');
+        $this->assertEquals($oldLinks[1]->name, 'mac_os_x');
+        $this->assertEquals($oldLinks[1]->link, 'http://www.apple.com/osx/');
+        $this->assertEquals($oldLinks[1]->link_type_id, 1);
+        $oldCompany = $project->getOldRelation('company');
+        $this->assertInstanceOf(Company::className(), $oldCompany);
+        $this->assertEquals($oldCompany->id, 1);
+        $this->assertEquals($oldCompany->name, 'Apple');
+        $this->assertTrue($project->save());
+        $oldLinks = $project->getOldRelation('links');
+        $this->assertInternalType('array', $oldLinks);
+        $this->assertEquals($oldLinks[0]->language, 'fr');
+        $this->assertEquals($oldLinks[0]->name, 'windows10');
+        $this->assertEquals($oldLinks[0]->link, 'https://www.microsoft.com/fr-fr/windows/features');
+        $this->assertEquals($oldLinks[0]->link_type_id, 2);
+        $this->assertEquals($oldLinks[1]->language, 'en');
+        $this->assertEquals($oldLinks[1]->name, 'windows10');
+        $this->assertEquals($oldLinks[1]->link, 'https://www.microsoft.com/en-us/windows/features');
+        $this->assertEquals($oldLinks[1]->link_type_id, 2);
+        $oldCompany = $project->getOldRelation('company');
+        $this->assertInstanceOf(Company::className(), $oldCompany);
+        $this->assertEquals($oldCompany->id, 2);
+        $this->assertEquals($oldCompany->name, 'Microsoft');
+
+    }
 }