New feature: split() with backwards option

thephpleague · Sep 6, 2017 · f02248f · f02248f
1 parent 2ccf17c
commit f02248f
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Showing 2 changed files with 92 additions and 1 deletion.
diff --git a/src/Period.php b/src/Period.php
@@ -877,7 +877,7 @@ public function merge(Period $arg)
     }
 
     /**
-     * Split a Period by a given interval
+     * Split a Period by a given interval (from start to end)
      *
      * The interval can be
      * <ul>
@@ -905,6 +905,35 @@ public function split($interval)
         } while ($startDate < $this->endDate);
     }
 
+    /**
+     * Split a Period by a given interval (from end to start)
+     *
+     * The interval can be
+     * <ul>
+     * <li>a DateInterval object</li>
+     * <li>an int interpreted as the duration expressed in seconds.</li>
+     * <li>a string in a format supported by DateInterval::createFromDateString</li>
+     * </ul>
+     *
+     * @param DateInterval|int|string $interval The interval
+     *
+     * @return Generator|Period[]
+     */
+    public function splitBackwards($interval)
+    {
+        $endDate = $this->endDate;
+        $interval = static::filterDateInterval($interval);
+        do {
+            $startDate = $endDate->sub($interval);
+            if ($startDate < $this->startDate) {
+                $startDate = $this->startDate;
+            }
+            yield new static($startDate, $endDate);
+
+            $endDate = $startDate;
+        } while ($endDate > $this->startDate);
+    }
+
     /**
      * Computes the intersection between two Period objects.
      *

diff --git a/test/PeriodTest.php b/test/PeriodTest.php
@@ -154,6 +154,68 @@ public function testSplitWithInconsistentInterval()
         $this->assertEquals(14400, $last->getTimestampInterval());
     }
 
+    public function testSplitData()
+    {
+        $period = Period::createFromDuration(new DateTime('2015-01-01'), '3 days');
+        $range = $period->split('1 day');
+        $result = array_map(function (Period $range) {
+            return [
+                'start' => $range->getStartDate()->format('Y-m-d H:i:s'),
+                'end'   => $range->getEndDate()->format('Y-m-d H:i:s')
+            ];
+        }, iterator_to_array($range));
+        $expected = [
+            [
+                'start' => '2015-01-01 00:00:00',
+                'end'   => '2015-01-02 00:00:00',
+            ],
+            [
+                'start' => '2015-01-02 00:00:00',
+                'end'   => '2015-01-03 00:00:00',
+            ],
+            [
+                'start' => '2015-01-03 00:00:00',
+                'end'   => '2015-01-04 00:00:00',
+            ],
+        ];
+        $this->assertSame($expected, $result);
+    }
+
+    public function testSplitDataBackwards()
+    {
+        $period = Period::createFromDuration(new DateTime('2015-01-01'), '3 days');
+        $range = $period->splitBackwards('1 day');
+        $result = array_map(function (Period $range) {
+            return [
+                'start' => $range->getStartDate()->format('Y-m-d H:i:s'),
+                'end'   => $range->getEndDate()->format('Y-m-d H:i:s')
+            ];
+        }, iterator_to_array($range));
+        $expected = [
+            [
+                'start' => '2015-01-03 00:00:00',
+                'end'   => '2015-01-04 00:00:00',
+            ],
+            [
+                'start' => '2015-01-02 00:00:00',
+                'end'   => '2015-01-03 00:00:00',
+            ],
+            [
+                'start' => '2015-01-01 00:00:00',
+                'end'   => '2015-01-02 00:00:00',
+            ],
+        ];
+        $this->assertSame($expected, $result);
+    }
+
+    public function testSplitBackwardsWithInconsistentInterval()
+    {
+        $period = Period::createFromDuration('2010-01-01', '1 DAY');
+        $range = iterator_to_array($period->splitBackwards('10 HOURS'));
+        $last = array_pop($range);
+        $this->assertEquals(14400, $last->getTimestampInterval());
+    }
+
     public function testSetState()
     {
         if (!method_exists(DateTimeImmutable::class, '__set_state')) {