Add 'on' filter

src/Yasumi/Filters/OnFilter.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * This file is part of the Yasumi package.
+ *
+ * Copyright (c) 2015 - 2018 AzuyaLabs
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @author Clark Seanor <[email protected]>
+ * @author Sacha Telgenhof <[email protected]>
+ */
+
+namespace Yasumi\Filters;
+
+use Countable;
+use FilterIterator;
+use Iterator;
+
+/**
+ * OnFilter is a class used for filtering holidays based on a given date.
+ *
+ * Filters for all holidays that happen on the given date.
+ *
+ * Note: this class can be used separately, however is implemented by the AbstractProvider::on method.
+ *
+ * @package Yasumi\Filters
+ */
+class OnFilter extends FilterIterator implements Countable
+{
+    /**
+     * @var string date to check for holidays
+     */
+    private $date;
+
+
+    /**
+     * Construct the On FilterIterator Object
+     *
+     * @param \Iterator          $iterator   Iterator object of the Holidays Provider
+     * @param \DateTimeInterface $date Start date of the time frame to check against
+     */
+
+    public function __construct(
+        Iterator $iterator,
+        \DateTimeInterface $date
+    ) {
+        parent::__construct($iterator);
+        $this->date      = $date->format('Y-m-d');
+    }
+
+    /**
+     * @return bool Check whether the current element of the iterator is acceptable
+     */
+    public function accept(): bool
+    {
+        $holiday = $this->getInnerIterator()->current()->format('Y-m-d');
+        return $holiday == $this->date;
+    }
+
+    /**
+     * @return integer Returns the number of holidays that happen on the specified date
+     */
+    public function count(): int
+    {
+        $days = \array_keys(\iterator_to_array($this));
+
+        \array_walk($days, function (&$day) {
+            $day = \str_replace('substituteHoliday:', '', $day);
+        });
+
+        return \count(\array_unique($days));
+    }
+}

src/Yasumi/Provider/AbstractProvider.php

@@ -17,6 +17,7 @@
 use InvalidArgumentException;
 use IteratorAggregate;
 use Yasumi\Filters\BetweenFilter;
+use Yasumi\Filters\OnFilter;
 use Yasumi\Holiday;
 use Yasumi\ProviderInterface;
 use Yasumi\TranslationsInterface;
@@ -443,6 +444,25 @@ public function between(\DateTimeInterface $start_date, \DateTimeInterface $end_
         return new BetweenFilter($this->getIterator(), $start_date, $end_date, $equals);
     }
 
+
+    /**
+     * Retrieves a list of all holidays that happen on the given date.
+     *
+     * Yasumi only calculates holidays for a single year, so a date outside of the given year will not appear to
+     * contain any holidays.
+     *
+     * Please take care to use the appropriate timezone for the date parameters. If there is a different timezone used
+     * for these parameters versus the instantiated Holiday Provider, the outcome might be unexpected (but correct).
+     *
+     * @param \DateTimeInterface $date Date to check for holidays on.
+     *
+     * @return \Yasumi\Filters\OnFilter
+     */
+    public function on(\DateTimeInterface $date): OnFilter
+    {
+        return new OnFilter($this->getIterator(), $date);
+    }
+
     /**
      * Get an iterator for the holidays.
      *

tests/Base/HolidayOnFilterTest.php

@@ -0,0 +1,92 @@
+<?php
+/**
+ * This file is part of the Yasumi package.
+ *
+ * Copyright (c) 2015 - 2018 AzuyaLabs
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @author Clark Seanor <[email protected]>
+ * @author Sacha Telgenhof <[email protected]>
+ */
+
+namespace Yasumi\tests\Base;
+
+use DateTime;
+use DateTimeZone;
+use InvalidArgumentException;
+use PHPUnit\Framework\TestCase;
+use Yasumi\tests\YasumiBase;
+use Yasumi\Yasumi;
+
+/**
+ * Class HolidayOnFilterTest.
+ *
+ * Contains tests for testing the OnFilter class
+ */
+class HolidayOnFilterTest extends TestCase
+{
+    use YasumiBase;
+
+    /**
+     * Tests the basic usage of the OnFilter.
+     */
+    public function testHolidaysOnDate()
+    {
+        $timezone = 'Europe/Amsterdam';
+        $holidays = Yasumi::create('Netherlands', 2016);
+
+        $holidayDates = [
+            'goodFriday' => new DateTime('03/25/2016', new DateTimeZone($timezone)),
+            'easter' => new DateTime('03/27/2016', new DateTimeZone($timezone)),
+            'summerTime' => new DateTime('03/27/2016', new DateTimeZone($timezone))
+        ];
+
+        foreach ($holidayDates as $name => $date) {
+            $holidaysOnDate = $holidays->on(
+                $date
+            );
+
+            $this->assertArrayHasKey($name, \iterator_to_array($holidaysOnDate));
+        }
+    }
+
+    public function testHolidaysNotOnDate()
+    {
+        $timezone = 'Europe/Amsterdam';
+        $holidays = Yasumi::create('Netherlands', 2016);
+
+        $holidayWrongDates = [
+            'goodFriday' => new DateTime('04/25/2016', new DateTimeZone($timezone)),
+            'easter' => new DateTime('03/22/2016', new DateTimeZone($timezone)),
+            'summerTime' => new DateTime('12/27/2016', new DateTimeZone($timezone))
+        ];
+
+        foreach ($holidayWrongDates as $name => $date) {
+            $holidaysOnDate = $holidays->on(
+                $date
+            );
+
+            $this->assertArrayNotHasKey($name, \iterator_to_array($holidaysOnDate));
+        }
+    }
+
+    public function testCorrectNumberOfHolidaysOnDate()
+    {
+        $timezone = 'Europe/Amsterdam';
+        $holidays = Yasumi::create('Netherlands', 2016);
+
+        // No holidays
+        $holidaysOnDate = $holidays->on(new \DateTime('11/19/2016', new DateTimeZone($timezone)));
+        $this->assertEquals(0, $holidaysOnDate->count());
+
+        // One holiday
+        $holidaysOnDate = $holidays->on(new \DateTime('12/25/2016', new DateTimeZone($timezone)));
+        $this->assertEquals(1, $holidaysOnDate->count());
+
+        // Multiple holidays
+        $holidaysOnDate = $holidays->on(new \DateTime('03/27/2016', new DateTimeZone($timezone)));
+        $this->assertGreaterThan(1, $holidaysOnDate->count());
+    }
+}