2つの日付とルールで配列を並べ替えます。

Question

イベントの予定表を作成しています。イベントの開始日と終了日は、YYYYMMDDの形式で格納されます。イベントリストは1日に表示され、イベントは1日または複数日にわたることができます。

イベントは現在start_dateとend_date

で、配列に格納されているどのようにすることができます：

• 移動 配列の先頭に現在の日付に開始されたイベント。
• そして、その後

終了日でイベントを並べ替える開始日

でイベントを並べ替えるには、このquestionを見ましたが、私は上記のロジックを構築する方法を放浪します。

Answer 1

現在の日付から開始するイベントを配列の先頭に移動しますが、他のイベントはそのまま並べ替えてください！開始日によって

$today = date('Ymd',strtotime('today')); 
usort($events,function($a,$b) use($today){ 
    if($a['start_date'] === $today && $b['start_date'] != $today){return -1;} 
    else if($b['start_date'] === $today && $a['start_date'] != $today){return 1;} 
    else {return strnatcmp($a['start_date'],$b['start_date']);} 
}); 

またはソートイベント

usort($events,function($a,$b){ 
    return strnatcmp($a['start_date'],$b['start_date']); 
}); 

または終了日までイベントソート

usort($events,function($a,$b){ 
    return strnatcmp($a['end_date'],$b['end_date']); 
}); 

EDITいくつかのテストデータ：

//example works best if today is 20170810 
$events = array(
    array(
    'name' => 'a', 
    'start_date' => '20170810', 
    'end_date' => '20170811', 
), 
    array(
    'name' => 'b', 
    'start_date' => '20170810', 
    'end_date' => '20170810', 
), 
    array(
    'name' => 'c', 
    'start_date' => '20170607', 
    'end_date' => '20170608', 
), 
    array(
    'name' => 'd', 
    'start_date' => '20170607', 
    'end_date' => '20170607', 
), 
    array(
    'name' => 'e', 
    'start_date' => '20170810', 
    'end_date' => '20170812', 
), 
    array(
    'name' => 'f', 
    'start_date' => '20170807', 
    'end_date' => '20170817', 
), 
); 
print_r($events); 

EDIT：それらのすべてを一緒に：進行中のイベントがあります「で注文されていますイベントは '？彼らは今日始めている'、 'START_DATE'、 'END_DATE'

$today = date('Ymd',strtotime('today')); 
usort($events,function($a,$b) use($today){ 
    //one of them starts today 
    if($a['start_date'] === $today && $b['start_date'] != $today){return -1;} 
    else if($b['start_date'] === $today && $a['start_date'] != $today){return 1;} 
    //both or neither start today, compare start_date 
    else { 
    if($a['start_date'] != $b['start_date']){ 
     //start_dates differ, order by them 
     return strnatcmp($a['start_date'],$b['start_date']); 
    } else { 
     //start dates are the same, order by end_date 
     return strnatcmp($a['end_date'],$b['end_date']); 
    } 
    } 
}); 

print_r($events); 

EDITを順に並んでい彼らは現在、進行中 ' 'START_DATE'、 'END_DATE'

$today = date('Ymd',strtotime('today')); 
//function compares two elements to decide their position relative to each other 
usort($events,function($a,$b) use($today){ 
    //check if event is currently ongoing 
    //starts or ends today or today is between start and end 
    $ongoing = function($event) use($today){ 
    //this is the simplest form I could think of for the check 
    return (strnatcmp($event['start_date'],$today) < 1 && strnatcmp($today,$event['end_date']) < 1); 
    }; 
    $startstoday = function($event) use($today){ 
    return $event['start_date'] === $today; 
    }; 
    //only one of them is ongoing 
    if($ongoing($a) && !$ongoing($b)){return -1;} 
    else if($ongoing($b) && !$ongoing($a)){return 1;} 
    //both or neither are ongoing, compare start_date 
    else { 
    if($a['start_date'] != $b['start_date']){ 
     //start_dates differ, order by them 
     return strnatcmp($a['start_date'],$b['start_date']); 
    } else { 
     //start dates are the same, order by end_date 
     return strnatcmp($a['end_date'],$b['end_date']); 
    } 
    } 
}); 

print_r($events); 

EDIT：今日から、継続的なイベントが順に並んでい '？彼らは今日始めている'、' いますか？ ？彼らは現在、進行中」、 'START_DATE'、 'END_DATE'

$today = date('Ymd',strtotime('today')); 
//function compares two elements to decide their position relative to each other 
usort($events,function($a,$b) use($today){ 
    //check if event is currently ongoing 
    //starts or ends today or today is between start and end 
    $ongoing = function($event) use($today){ 
    //this is the simplest form I could think of for the check 
    return (strnatcmp($event['start_date'],$today) < 1 && strnatcmp($today,$event['end_date']) < 1); 
    }; 
    //only one of them is ongoing 
    if($ongoing($a) && !$ongoing($b)){return -1;} 
    else if($ongoing($b) && !$ongoing($a)){return 1;} 
    //both are ongoing 
    else if($ongoing($a) && $ongoing($b)){ 
    //one starts today 
    if($a['start_date'] === $today && $b['start_date'] != $today){return -1;} 
    else if($b['start_date'] === $today && $a['start_date'] != $today){return 1;} 
    //both start today 
    else if($a['start_date'] === $today && $b['start_date'] === $today){ 
     return strnatcmp($a['end_date'],$b['end_date']); 
    } 
    //none starts today 
    else { 
     if($a['start_date'] != $b['start_date']){ 
     //start_dates differ, order by them 
     return strnatcmp($a['start_date'],$b['start_date']); 
     } else { 
     //start dates are the same, order by end_date 
     return strnatcmp($a['end_date'],$b['end_date']); 
     } 
    } 
    } else { 
    //neither are ongoing, compare start_date 
    if($a['start_date'] != $b['start_date']){ 
     //start_dates differ, order by them 
     return strnatcmp($a['start_date'],$b['start_date']); 
    } else { 
     //start dates are the same, order by end_date 
     return strnatcmp($a['end_date'],$b['end_date']); 
    } 
    } 
}); 

print_r($events); 

と、この最後のONEを簡略化することができるTO：

$today = date('Ymd',strtotime('today')); 
usort($events,function($a,$b) use($today){ 
    $ongoing = function($event) use($today){ 
    return (strnatcmp($event['start_date'],$today) < 1 && strnatcmp($today,$event['end_date']) < 1); 
    }; 
    if($ongoing($a)){ 
    if(!$ongoing($b)){return -1;} 
    else { 
     if($a['start_date'] === $today && $b['start_date'] != $today){return -1;} 
     else if($b['start_date'] === $today && $a['start_date'] != $today){return 1;} 
    } 
    } else if($ongoing($b)){return 1;} 
    if($a['start_date'] != $b['start_date']){ 
    return strnatcmp($a['start_date'],$b['start_date']); 
    } else { 
    return strnatcmp($a['end_date'],$b['end_date']); 
    } 
}); 

print_r($events);