From 6b9c7d95f2e7d7e639973f48dee46c0cc7c918dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kucha=C5=99?= <honza.kuchar@grifart.cz>
Date: Sat, 21 May 2016 15:16:36 +0200
Subject: [PATCH] Position: Value Object is now immutable (as described in
Domain Driven Design by Eric Evans)
---
src/Position.php | 50 ++++++++++++++-----------------------------
src/TrackedCursor.php | 45 ++++++++++++++++++--------------------
2 files changed, 37 insertions(+), 58 deletions(-)
diff --git a/src/Position.php b/src/Position.php
index ff4f203..8a8e9ef 100644
--- a/src/Position.php
+++ b/src/Position.php
@@ -5,10 +5,9 @@
namespace Grifart\Mappi\Cursor;
-// todo: make this immutable as VOs should be
-
/**
- * Value object for TrackedCursor position
+ * Value Object that holds position of cursor
+ * use by {@see TrackedCursor}
*
* @link https://github.com/nicolopignatelli/valueobjects (inspiration)
* @package Grifart\Mappi\Cursor
@@ -25,9 +24,13 @@ final class Position
* @param PositionOrigin $origin from left or from right?
* @param int $position which position
*/
- public function __construct(PositionOrigin $origin, int $position)
+ private function __construct(PositionOrigin $origin, int $position)
{
- $this->setPosition($origin, $position);
+ if($position < 0) {
+ throw CursorException::cursorPosition_invalidIndexValue($position);
+ }
+ $this->origin = $origin;
+ $this->position = $position;
}
public static function fromLeft(int $position) : self
@@ -45,36 +48,15 @@ final class Position
$position
);
}
-
- public function setPositionFromLeft(int $position)
- {
- $this->setPosition(PositionOrigin::get(PositionOrigin::FROM_LEFT), $position);
- }
-
- public function setPositionFromRight(int $position)
- {
- $this->setPosition(PositionOrigin::get(PositionOrigin::FROM_RIGHT), $position);
- }
-
- private function setPosition(PositionOrigin $origin, int $position)
- {
- if($position < 0) {
- throw CursorException::cursorPosition_invalidIndexValue($position);
- }
- $this->origin = $origin;
- $this->position = $position;
- }
-
- /**
- * @param int $by negative = left; positive = right
- */
- public function movePositionBy(int $by)
+
+ public static function relativeTo(Position $position, int $offset) : self
{
- $modifier = 1;
- if ($this->origin->is(PositionOrigin::FROM_RIGHT)) {
- $modifier = -1;
- }
- $this->position += $modifier * $by;
+ $positionDelta = ($position->getOrigin()
+ ->is(PositionOrigin::FROM_LEFT) ? 1 : -1) * $offset;
+ return new self(
+ $position->getOrigin(),
+ $position->getPosition() + $positionDelta
+ );
}
/**
diff --git a/src/TrackedCursor.php b/src/TrackedCursor.php
index 2d1ceb2..cf92d01 100644
--- a/src/TrackedCursor.php
+++ b/src/TrackedCursor.php
@@ -47,18 +47,16 @@ class TrackedCursor implements ICursor
{
$this->cursor->moveTo($index);
if ($this->cursor->isOnRecord()) {
- $this->position->setPositionFromLeft(
- $index
- );
+ $this->position = Position::fromLeft($index);
return;
}
if ($index === 0) {
- $this->position->setPositionFromLeft(0); // BEGINNING
+ $this->position = Position::fromLeft(0); // BEGINNING
return;
}
if ($index > 0 ) {
- $this->position->setPositionFromRight(0); // END
+ $this->position = Position::fromRight(0); // END
return;
}
throw CursorException::cursorPosition_unknownError();
@@ -68,18 +66,16 @@ class TrackedCursor implements ICursor
{
$this->cursor->moveFromEndTo($index);
if ($this->cursor->isOnRecord()) {
- $this->position->setPositionFromRight(
- $index
- );
+ $this->position = Position::fromRight($index);
return;
}
if ($index === 0) {
- $this->position->setPositionFromRight(0); // END
+ $this->position = Position::fromRight(0); // END
return;
}
if ($index > 0) {
- $this->position->setPositionFromLeft(0); // BEGINNING
+ $this->position = Position::fromLeft(0); // BEGINNING
return;
}
throw CursorException::cursorPosition_unknownError();
@@ -90,15 +86,15 @@ class TrackedCursor implements ICursor
// todo: use MOVE FORWARD n IN ... which returns number of rows read
$this->cursor->moveBy($offset);
if ($this->cursor->isOnRecord()) {
- $this->position->movePositionBy($offset);
+ $this->position = Position::relativeTo($this->position, $offset);
return;
}
if ($offset < 0) {
- $this->position->setPositionFromLeft(0); // BEGINNING
+ $this->position = Position::fromLeft(0); // BEGINNING
return;
}
if ($offset > 0) {
- $this->position->setPositionFromRight(0); // END
+ $this->position = Position::fromRight(0); // END
return;
}
if ($offset === 0) {
@@ -118,17 +114,18 @@ class TrackedCursor implements ICursor
$count = count($result);
$reachedEnd = $count < abs($offset);
if(!$reachedEnd) {
- $this->position->movePositionBy(
+ $this->position = Position::relativeTo(
+ $this->position,
$count * ($forward ? 1 : -1)
);
return $result;
}
if($forward) {
- $this->position->setPositionFromRight(0); // right END
+ $this->position = Position::fromRight(0); // right END
return $result;
} else {
- $this->position->setPositionFromLeft(0); // left END
+ $this->position = Position::fromLeft(0); // left END
return $result;
}
}
@@ -138,24 +135,24 @@ class TrackedCursor implements ICursor
$row = $this->cursor->fetchOneAt($index);
if ($row !== NULL) {
if($index < 0) {
- $this->position->setPositionFromRight(abs($index));
+ $this->position = Position::fromRight(abs($index));
} else /* >= 0 */ {
- $this->position->setPositionFromLeft($index);
+ $this->position = Position::fromLeft(abs($index));
}
return $row;
}
if ($index === 0) {
- $this->position->setPositionFromLeft(0); // BEGINNING
+ $this->position = Position::fromLeft(0); // BEGINNING
return NULL;
}
if ($index < 0) { // went from right to left -> hit beginning
- $this->position->setPositionFromLeft(0);
+ $this->position = Position::fromLeft(0);
return NULL;
}
if ($index > 0) { // went left->right -> hit end
- $this->position->setPositionFromRight(0);
+ $this->position = Position::fromRight(0);
return NULL;
}
@@ -166,16 +163,16 @@ class TrackedCursor implements ICursor
{ // todo: content tests
$row = $this->cursor->fetchOneBy($offset);
if ($row !== NULL) {
- $this->position->movePositionBy($offset);
+ $this->position = $this->position = Position::relativeTo($this->position, $offset);
return $row;
}
if ($offset < 0) {
- $this->position->setPositionFromLeft(0); // BEGINNING
+ $this->position = Position::fromLeft(0); // BEGINNING
return NULL;
}
if ($offset > 0) {
- $this->position->setPositionFromRight(0); // END
+ $this->position = Position::fromRight(0); // END
return NULL;
}
if ($offset === 0) {
--
GitLab