Implementing find('threaded') to showcase again how to use map-reduce...

Still hacks the end result by returning objects instead of arrays, this can almost trivially be fixed later, though
cakephp · Aug 17, 2013 · ea4cf1f · ea4cf1f
1 parent 6fbdb04
commit ea4cf1f
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Showing 4 changed files with 88 additions and 17 deletions.
diff --git a/lib/Cake/ORM/MapReduce.php b/lib/Cake/ORM/MapReduce.php
@@ -35,10 +35,10 @@ class MapReduce implements IteratorAggregate {
 
 	protected $_counter = 0;
 
-	public function __construct($data, callable $mapper, callable $reducer) {
+	public function __construct($data, array $routines) {
 		$this->_data = $data;
-		$this->_mapper = $mapper;
-		$this->_reducer = $reducer;
+		$this->_mapper = $routines['mapper'];
+		$this->_reducer = isset($routines['reducer']) ? $routines['reducer'] : null;
 	}
 
 	public function getIterator() {
@@ -54,6 +54,7 @@ public function emitIntermediate($key, $value) {
 
 	public function emit($value, $slot = null) {
 		$this->_result[$slot === null ? $this->_counter : $slot] = $value;
+		$this->_counter++;
 	}
 
 	protected function _execute() {
@@ -63,7 +64,6 @@ protected function _execute() {
 
 		foreach ($this->_intermediate as $key => $list) {
 			$this->_reducer->__invoke($key, $list, $this);
-			$this->_counter++;
 		}
 		$this->_execute = true;
 	}

diff --git a/lib/Cake/ORM/Query.php b/lib/Cake/ORM/Query.php
@@ -67,9 +67,7 @@ class Query extends DatabaseQuery {
  */
 	protected $_loadEagerly = [];
 
-	protected $_mapper;
-
-	protected $_reducer;
+	protected $_mapReduce = [];
 
 /**
  * List of options accepted by associations in contain()
@@ -529,21 +527,23 @@ public function applyOptions(array $options) {
 		return $this;
 	}
 
-	public function mapReduce(callable $mapper, callable $reducer) {
-		$this->_mapper = $mapper;
-		$this->_reducer = $reducer;
+	public function mapReduce(callable $mapper, callable $reducer = null) {
+		$this->_mapReduce[] = compact('mapper', 'reducer');
 		return $this;
 	}
 
 	protected function _applyFormatters($result) {
 		foreach ($this->_formatters as $formatter) {
 			$result = new ResultSetDecorator($result, $formatter);
 		}
-		if (!empty($this->_mapper) && !empty($this->_reducer)) {
-			$result = new ResultSetDecorator(
-				new MapReduce($result, $this->_mapper, $this->_reducer)
-			);
+
+		foreach ($this->_mapReduce as $mappers) {
+			$result = new MapReduce($result, $mappers);
 		}
+
+		if (!empty($this->_mapReduce)) {
+			$result = new ResultSetDecorator($result);
+		}	
 		return $result;
 	}
 

diff --git a/lib/Cake/ORM/Table.php b/lib/Cake/ORM/Table.php
@@ -525,7 +525,7 @@ public function findAll(Query $query, array $options = []) {
 	}
 
 	public function findList(Query $query, array $options = []) {
-		$mapper = function($key, $row, $mr) use ($query, &$columns) {
+		$mapper = function($key, $row, $mr) use (&$columns) {
 			if (empty($columns)) {
 				$columns = array_slice(array_keys($row), 0, 3);
 			}
@@ -540,7 +540,7 @@ public function findList(Query $query, array $options = []) {
 			$mr->emitIntermediate($key, [$row[$rowKey] => $row[$rowVal]]);
 		};
 
-		$reducer = function($key, $values, $mr) use (&$columns) {
+		$reducer = function($key, $values, $mr) {
 			$result = [];
 			foreach ($values as $value) {
 				$result += $value;
@@ -551,6 +551,22 @@ public function findList(Query $query, array $options = []) {
 		return $query->mapReduce($mapper, $reducer);
 	}
 
+	public function findThreaded(Query $query, array $options = []) {
+		$parents = new \ArrayObject;
+		$mapper = function($key, $row, $mr) use ($parents) {
+			$parents[$row['id']] = new \ArrayObject($row);
+			if (empty($row['parent_id'])) {
+				return $mr->emit($parents[$row['id']]);
+			}
+			$mr->emitIntermediate($row['parent_id'], $parents[$row['id']]);
+		};
+
+		$reducer = function($key, $values, $mr) use ($parents) {
+			$parents[$key]['children'] = $values;
+		};
+		return $query->mapReduce($mapper, $reducer);
+	}
+
 /**
  * Creates a new Query instance for this table
  *

diff --git a/lib/Cake/Test/TestCase/ORM/TableTest.php b/lib/Cake/Test/TestCase/ORM/TableTest.php
@@ -54,7 +54,7 @@ class MyUsersTable extends Table {
  */
 class TableTest extends \Cake\TestSuite\TestCase {
 
-	public $fixtures = ['core.user'];
+	public $fixtures = ['core.user', 'core.category'];
 
 	public function setUp() {
 		parent::setUp();
@@ -539,4 +539,59 @@ public function testFindList() {
 		$this->assertSame($expected, $query->toArray());
 	}
 
+	public function testFindThreaded() {
+		$table = new Table(['table' => 'categories', 'connection' => $this->connection]);
+		$expected = array(
+			new \ArrayObject(array(
+				'id' => 1,
+				'parent_id' => 0,
+				'name' => 'Category 1',
+				'children' => array(
+					new \ArrayObject(array(
+						'id' => 2,
+						'parent_id' => 1,
+						'name' => 'Category 1.1',
+						'children' => array(
+							new \ArrayObject(array(
+								'id' => 7,
+								'parent_id' => 2,
+								'name' => 'Category 1.1.1',
+							)),
+							new \ArrayObject(array(
+								'id' => 8,
+								'parent_id' => '2',
+								'name' => 'Category 1.1.2',
+							))
+						),
+					)),
+					new \ArrayObject(array(
+						'id' => 3,
+						'parent_id' => '1',
+						'name' => 'Category 1.2',
+					)),
+				)
+			)),
+			new \ArrayObject(array(
+				'id' => 4,
+				'parent_id' => 0,
+				'name' => 'Category 2',
+			)),
+			new \ArrayObject(array(
+				'id' => 5,
+				'parent_id' => 0,
+				'name' => 'Category 3',
+				'children' => array(
+					new \ArrayObject(array(
+						'id' => '6',
+						'parent_id' => '5',
+						'name' => 'Category 3.1',
+					))
+				)
+			))
+		);
+		$results = $table->find('threaded')
+			->select(['id', 'parent_id', 'name'])
+			->toArray();
+		$this->assertEquals($expected, $results);
+	}
 }