Question

我无法在laravel 5.5刀片中循环播放数组

1.-在我的控制器中我查询了一个dynamodb，我正在返回$ arrayRet

 $result =$dynamodb->query(array(
            'TableName' => 'sigfox',
            'KeyConditionExpression' => 'deviceid = :v_hash',
            'ExpressionAttributeValues' =>  array (
                ':v_hash'  => array('S' => '3E6231')
            )
        ));

        //echo "Query succeeded.\n";
        $arrayRet['signals'] = $result['Items'];
  return view('loggers.index', $arrayRet);

2.-在我的刀片中，我有以下代码

 @foreach($signals as $signal)
        <tr>
            <td>{{$signal['payload']['M']['data']['S']}}</td>  
        </tr>
 @endforeach

3.-我得到未定义的索引：数据---所以我已经dd（$ signal）这就是结果

array:3 [▼
"payload" => array:1 [▼
      "M" => array:10 [▼
  "avgSnr" => array:1 [▶]
  "rssi" => array:1 [▶]
  "data" => array:1 [▼
    "S" => "33333b414900"
  ]
  "lng" => array:1 [▶]
  "snr" => array:1 [▶]
  "station" => array:1 [▶]
  "seqNumber" => array:1 [▶]
  "time" => array:1 [▶]
  "device" => array:1 [▶]
  "lat" => array:1 [▶]
   ]
   ]
"deviceid" => array:1 [▶]
"timestamp" => array:1 [▶]
]

4.-我也尝试获得硬编码的价值并且它有效。但我必须使用@foreach

的“刀片方式”

       <tr>
            <td>{{$signals[0]['deviceid']['S']}}</td>
            <td>{{$signals[0]['timestamp']['S']}}</td>
            <td>{{$signals[0]['payload']['M']['avgSnr']['S']}}</td>
            <td>{{$signals[0]['payload']['M']['snr']['S']}}</td>
            <td>{{$signals[0]['payload']['M']['lat']['S']}}</td>
            <td>{{$signals[0]['payload']['M']['lng']['S']}}</td>
        </tr>

5.-也许我错过了什么，请告知

Answer 1

如果你使用PHP 7 null coalescing operator在这里非常有用！

@foreach(signals as signal)
   <tr>
        <td>{{ $signal['deviceid']['S'] ?? 'N/A' }}</td>
        <td>{{ $signal['timestamp']['S'] ?? 'N/A' }}</td>
        <td>{{ $signal['payload']['M']['avgSnr']['S'] ?? 'N/A' }}</td>
        <td>{{ $signal['payload']['M']['snr']['S'] ?? 'N/A' }}</td>
        <td>{{ $signal['payload']['M']['lat']['S'] ?? 'N/A' }}</td>
        <td>{{ $signal['payload']['M']['lng']['S'] ?? 'N/A' }}</td>
    </tr>
@endforeach

如果索引不存在，它将打印＆＃34; N / A＆＃34;作为默认值。

可以有更多改进！在发送视图之前创建一个模型来清理这些索引和所有内容，代码看起来像这样。在控制器中，处理此数据，然后再将其发送到视图。像array_map这样的函数在这里很有用。逻辑人员应该尽可能地完成视图。你的代码看起来会更整洁。

@foreach(signals as signal)
   <tr>
        <td>{{ $signal['deviceid'] }}</td>
        <td>{{ $signal['timestamp'] }}</td>
        <td>{{ $signal['avgSnr'] }}</td>
        <td>{{ $signal['snr'] }}</td>
        <td>{{ $signal['lat'] }}</td>
        <td>{{ $signal['lng'] }}</td>
    </tr>
@endforeach

循环多维数组Laravel

1 个答案: