From: Michael Wallner <mike@php.net>
Date: Tue, 12 Mar 2013 13:11:57 +0000 (+0100)
Subject: relations
X-Git-Tag: v1.0.0~7
X-Git-Url: https://git.m6w6.name/?a=commitdiff_plain;h=7045a269b4993d414337fcd7ee1b789b15185af4;p=m6w6%2Fpq-gateway

relations
---

diff --git a/lib/pq/Gateway/Row.php b/lib/pq/Gateway/Row.php
index 5b438e5..2493373 100644
--- a/lib/pq/Gateway/Row.php
+++ b/lib/pq/Gateway/Row.php
@@ -151,14 +151,13 @@ class Row implements \JsonSerializable
 	}
 	
 	/**
-	 * Get a cell
+	 * Get a cell or parent rows
 	 * @param string $p
 	 * @return \pq\Gateway\Cell|\pq\Gateway\Rowset
 	 */
 	function __get($p) {
-		if (isset($this->data["{$p}_id"])) {
-			// FIXME cache
-			return $this->getTable()->by($this, $p);
+		if ($this->table->hasRelation($p)) {
+			return $this->table->by($this, $p);
 		}
 		if (!isset($this->cell[$p])) {
 			$this->cell[$p] = new Cell($this, $p, isset($this->data[$p]) ? $this->data[$p] : null);
@@ -175,15 +174,37 @@ class Row implements \JsonSerializable
 		$this->__get($p)->set($v);
 	}
 	
+	/**
+	 * Unset a cell value
+	 * @param string $p
+	 */
 	function __unset($p) {
 		unset($this->data[$p]);
 		unset($this->cell[$p]);
 	}
 	
+	/**
+	 * Check if a cell isset
+	 * @param string $p
+	 * @return bool
+	 */
 	function __isset($p) {
 		return isset($this->data[$p]) || isset($this->cell[$p]);
 	}
 	
+	/**
+	 * Get child rows of this row by foreign key
+	 * @see \pq\Gateway\Table::of()
+	 * @param string $foreign
+	 * @param array $args [order, limit, offset]
+	 * @return \pq\Gateway\Rowset
+	 */
+	function __call($foreign, array $args) {
+		array_unshift($args, $this);
+		$table = forward_static_call(array(get_class($this->getTable()), "resolve"), $foreign);
+		return call_user_func_array(array($table, "of"), $args);
+	}
+	
 	/**
 	 * Create this row in the database
 	 * @return \pq\Gateway\Row
diff --git a/lib/pq/Gateway/Table.php b/lib/pq/Gateway/Table.php
index 7966911..af84e7f 100644
--- a/lib/pq/Gateway/Table.php
+++ b/lib/pq/Gateway/Table.php
@@ -12,6 +12,11 @@ class Table
 	 */
 	public static $defaultConnection;
 	
+	/**
+	 * @var callable
+	 */
+	public static $defaultResolver;
+	
 	/**
 	 * @var \pq\Connection
 	 */
@@ -36,21 +41,36 @@ class Table
 	 * @var \pq\Query\ExecutorInterface
 	 */
 	protected $exec;
-
+	
 	/**
-	 * @var array
+	 * @var \pq\Gateway\Table\Relations
 	 */
-	protected $dependents;
+	protected $relations;
 	
+	/**
+	 * @param string $table
+	 * @return \pq\Gateway\Table
+	 */
+	public static function resolve($table) {
+		if ($table instanceof Table) {
+			return $table;
+		}
+		if (is_callable(static::$defaultResolver)) {
+			if (($resolved = call_user_func(static::$defaultResolver, $table))) {
+				return $resolved;
+			}
+		}
+		return new Table($table);
+	}
+
 	/**
 	 * @param string $name
 	 * @param \pq\Connection $conn
 	 * @param array $dependents
 	 */
-	function __construct($name, \pq\Connection $conn = null, array $dependents = array()) {
+	function __construct($name, \pq\Connection $conn = null) {
 		$this->name = $name;
 		$this->conn = $conn ?: static::$defaultConnection ?: new \pq\Connection;
-		$this->dependents = $dependents;
 	}
 	
 	/**
@@ -113,6 +133,40 @@ class Table
 		return $this->exec;
 	}
 	
+	/**
+	 * Get foreign key relations
+	 * @param string $to fkey
+	 * @return \pq\Gateway\Table\Relations|stdClass
+	 */
+	function getRelations($to = null) {
+		if (!isset($this->relations)) {
+			$this->relations = new Table\Relations($this);
+		}
+		if (isset($to)) {
+			if (!isset($this->relations->$to)) {
+				return null;
+			}
+			return $this->relations->$to;
+		}
+		return $this->relations;
+	}
+	
+	/**
+	 * Check whether a certain relation exists
+	 * @param string $name
+	 * @param string $table
+	 * @return bool
+	 */
+	function hasRelation($name, $table = null) {
+		if (!($rel = $this->getRelations($name))) {
+			return false;
+		}
+		if (!isset($table)) {
+			return true;
+		}
+		return isset($rel->$table);
+	}
+	
 	/**
 	 * @return \pq\Connection
 	 */
@@ -133,6 +187,7 @@ class Table
 	 * @return mixed
 	 */
 	protected function execute(QueryWriter $query) {
+		echo $query,"\n",json_encode($query->getParams()),"\n";
 		return $this->getQueryExecutor()->execute($query, array($this, "onResult"));
 	}
 
@@ -141,8 +196,8 @@ class Table
 	 * @param \pq\Result $result
 	 * @return mixed
 	 */
-	public function onResult(\pq\Result $result) {
-		if ($result->status != \pq\Result::TUPLES_OK) {
+	public function onResult(\pq\Result $result = null) {
+		if ($result && $result->status != \pq\Result::TUPLES_OK) {
 			return $result;
 		}
 		
@@ -181,40 +236,53 @@ class Table
 	}
 	
 	/**
-	 * Get the parent row of a row by foreign key
-	 * @param \pq\Gateway\Row $dependent
+	 * Get the child rows of a row by foreign key
+	 * @param \pq\Gateway\Row $foreign
 	 * @param string $name optional fkey name
 	 * @param string $order
 	 * @param int $limit
 	 * @param int $offset
 	 * @return mixed
 	 */
-	function of(Row $dependent, $name = null, $order = null, $limit = 0, $offset = 0) {
-		if (!$name) {
-			$name = $dependent->getTable()->getName();
+	function of(Row $foreign, $name = null, $order = null, $limit = 0, $offset = 0) {
+		// select * from $this where $this->$foreignColumn = $foreign->$referencedColumn
+		
+		if (!isset($name)) {
+			$name = $this->getName();
+		}
+		
+		if (!$foreign->getTable()->hasRelation($name, $this->getName())) {
+			return $this->onResult(null);
 		}
-		return $this->find(array("{$name}_id=" => $dependent->id),
-			$order, $limit, $offset);
+		$rel = $foreign->getTable()->getRelations($name)->{$this->getName()};
+		
+		return $this->find(
+			array($rel->foreignColumn . "=" => $foreign->{$rel->referencedColumn}),
+			$order, $limit, $offset
+		);
 	}
 	
 	/**
-	 * Get the child rows of a row by foreign key
+	 * Get the parent rows of a row by foreign key
 	 * @param \pq\Gateway\Row $me
-	 * @param string $dependent
+	 * @param string $foreign
 	 * @param string $order
 	 * @param int $limit
 	 * @param int $offset
 	 * @return mixed
-	 * @throws \LogicException
 	 */
-	function by(Row $me, $dependent, $order = null, $limit = 0, $offset = 0) {
-		if (!isset($this->dependents[$dependent])) {
-			throw new \LogicException("Unknown dependent table $dependent");
+	function by(Row $me, $foreign, $order = null, $limit = 0, $offset = 0) {
+		// select * from $foreign where $foreign->$referencedColumn = $me->$foreignColumn
+		
+		if (!$this->hasRelation($foreign, $this->getName())) {
+			return $this->onResult(null);
 		}
+		$rel = $this->getRelations($foreign)->{$this->getName()};
 		
-		$dependentClass = $this->dependents[$dependent];
-		$dependentModel = new $dependentClass($this->conn);
-		return $dependentModel->of($me, null, $order, $limit, $offset);
+		return static::resolve($rel->referencedTable)->find(
+			array($rel->referencedColumn . "=" => $me->{$rel->foreignColumn}),
+			$order, $limit, $offset
+		);
 	}
 
 	/**
diff --git a/lib/pq/Gateway/Table/Relations.php b/lib/pq/Gateway/Table/Relations.php
new file mode 100644
index 0000000..0f946fa
--- /dev/null
+++ b/lib/pq/Gateway/Table/Relations.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Table;
+
+const RELATION_SQL = <<<SQL
+select
+	 substring(att1.attname from '^.*(?=_'||att2.attname||'$)') as "id"
+	,cl1.relname                                                as "foreignTable"
+    ,att1.attname                                               as "foreignColumn"
+	,cl2.relname                                                as "referencedTable"
+    ,att2.attname                                               as "referencedColumn"
+from
+     pg_constraint co
+    ,pg_class      cl2
+    ,pg_class      cl1
+    ,pg_attribute  att2
+    ,pg_attribute  att1
+where
+	(	cl1.relname = \$1
+	or	cl2.relname = \$1)
+and co.confrelid != 0
+and co.confrelid  = cl2.oid
+and co.conrelid   = cl1.oid
+and co.confkey[1] = att2.attnum and cl2.oid = att2.attrelid
+and co.conkey[1]  = att1.attnum and cl1.oid = att1.attrelid
+order by 
+	 cl1.relname
+	,att1.attnum
+SQL;
+
+class Relations
+{
+	public $references;
+	
+	function __construct(Table $table) {
+		// FIXME cache
+		$this->references = $table->getConnection()
+			->execParams(RELATION_SQL, array($table->getName()))
+			->map(array(0,1), array(2,3,4), \pq\Result::FETCH_OBJECT);
+	}
+	
+	function __isset($r) {
+		return isset($this->references->$r);
+	}
+	
+	function __get($r) {
+		return $this->references->$r;
+	}
+	
+	function __set($r, $v) {
+		$this->references->$r = $v;
+	}
+	
+	function __unset($r){
+		unset($this->references->$r);
+	}
+}