代码之家 › 专栏 › 技术社区 › TheOrdinaryGeek

Codeigniter表库句柄空/空值

codeigniter-3 foreach codeigniter arrays php

TheOrdinaryGeek · 技术社区 · 6 年前

我用的是CodeIgniter3和 table library 以便按以下格式显示某些数据;

+---------------+---------------------+
| id            | 102                 |
+---------------+---------------------+
| First Name    | Ross                |
+---------------+---------------------+
| Last Name     | Bing                |
+---------------+---------------------+
| Title         | Doctor              |
+---------------+---------------------+
| Timestamp     | 2019-01-18 10:17:05 |
+---------------+---------------------+
| Member Number |                     |
+---------------+---------------------+

一堆垃圾 $tableData 是;

Array
(
    [0] => Array
        (
            [id] => 102
            [firstname] => Ross
            [lastname] => Bing
            [title] => Doctor
            [timestamp] => 2019-01-18 10:17:05
            [member_no] => 
        )
)

我用来生成HTML表的PHP代码是;

$tableData = $this->My_model->getData();

$heading = array(
    'id' => 'ID',
    'firstname' => 'First Name',
    'lastname' => 'Last Name',
    'title' => 'Title',
    'timestamp' => 'Date Submitted',
    'member_no' => 'Member Number'
);

$fields = array_keys($tableData[0]);
$rows = array();

foreach($fields as $key => $field) {
    $rows[$key][0] = array(
        'data' => '<strong>' . $heading[$field] . '</strong>'
    );
    foreach($tableData as $key2 => $item) {
        $rows[$key][$key2 + 1] = $item[$field];
    }
}

foreach($rows as $row) {
    $this->table->add_row($row);
}

但是,如果一行是空的,则上面的代码可以正常工作(请参见 member_no

完全隐藏表行
显示 not available

我怎样才能做到这一点?

0 回复 | 直到 6 年前

ArtisticPhoenix 6 年前

我会这样做:

$tableData = array (
    0 => 
    array (
        'id' => 102,
        'lastname' => 'Bing',
        'title' => 'Doctor',
        'timestamp' => '2019-01-1810:17:05',
        'member_no' => null,
        'firstname' => 'Ross', //intentionally moved to show ordering
        'foobar' => 'blah' //added for example, this will be removed by array_intersect_key
    ),
);

$heading = array(
    'id' => '<strong>ID</strong>',
    'firstname' => '<strong>First Name</strong>',
    'lastname' => '<strong>Last Name</strong>',
    'title' => '<strong>Title</strong>',
    'timestamp' => '<strong>Date Submitted</strong>',
    'member_no' => '<strong>Member Number</strong>'
);

//create a default array
//this takes the keys from $heading, and makes an array with all the values as 'not available'
// ['id' => 'not available','lastname' => 'not available', ... ]
$default = array_fill_keys(array_keys($heading), 'not available');
$rows = [];

foreach($tableData as $key => $row) {
    //remove all elements with strlen of 0 (in this case 'member_no')
    $row = array_filter($row, function($item){return strlen($item);});

    //removes 'foobar' or anything that has a key not in $heading
    $row = array_intersect_key($row, $heading);

    //combine $default and $data (empty items in $row are filled in from default)
    //such as items removed by array_filter above
    //the key order will match $default, which matches $headings
    $row = array_merge($default, $row);

    $rows[] = $row;
}

foreach($heading as $key=>$value) {
    print_r(array_merge([['data'=>$value]], array_column($rows, $key)));
}

输出

Array
(
    [0] => Array
        (
            [data] => <strong>ID</strong>
        )

    [1] => 102
    //[2] => 108
    //...
)
 ....

Sandbox

//...
$default = array_fill_keys(array_keys($heading), 'not available');

foreach($tableData as $key => $row) $rows[] = array_merge($default, array_intersect_key(array_filter($row, function($item){return strlen($item);}), $heading));

foreach($heading as $key=>$value) print_r(array_merge([['data'=>$value]],array_column($rows, $key)));

Sandbox

我不得不猜测一下最终的结果是什么,所以我运行了你的原始代码,它给了我这个:

Array
(
    [0] => Array
        (
            [data] => <strong>ID</strong>
        )

    [1] => 102
    //[2] => 108
    //...
)
....

在我的代码中,你可以替换 print_r 有了这个电话 $this->table->add_row([..array data..]); . 在哪里? array data 里面的东西 打印\r

关键顺序 $headings 元素会出现在 $标题 数组,无论它们在何处 $tableData . 这也允许轻松地重新排序数据,例如:您甚至可以将其映射到一个动态数组,我在CSV文件中这样做,它允许用户更改标题和列的顺序。他们甚至可以重命名标题,因为 key => value 配对工作 my_key => their_key ...
中缺少数据 $表格数据 not available 从 $default ,理论上你可以手动将其映射到不同的东西。例如:您可以通过 $default['timestamp'] = date('Y-m-d H:i:s'); 就在用 array_fill_keys .
中的额外数据中未定义 $标题
而且它更容易理解(一旦你知道它是如何工作的),因为有更少的“瞬态”变量和更少的摆弄键等。。。

基本上我所做的就是把控制权交给 $标题 数组,在原始代码中。你可以通过循环键来实现这一点( fields ),但这会让以后的事情变得更复杂 $rows[$key][$key2 + 1] . 如果以后数据发生更改(例如向数据库中添加新字段),则会出现未定义的数组索引问题。输出的顺序取决于中的数据 $表格数据 $标题 .

以下是原始代码中这些问题的示例:

//for example if your data changes to this and run your original code
 $tableData = array (
 0 => 
    array (
        'id' => 102,
        'lastname' => 'Bing',
        'title' => 'Doctor',
        'timestamp' => '2019-01-1810:17:05',
        'member_no' => null,
        'firstname' => 'Ross', //intentionally moved to show ordering
        'foo' => 'bar' //added this undefined in $headings
    ),
);

您将看到此通知,并发现最后两个元素是:

 <br />
 <b>Notice</b>:  Undefined index: foo in <b>[...][...]</b> on line <b>30</b><br />
 //... all other elements ...

 //in orignal: displayed in the order of $tableData
 //in my code: order is based on $headings, so this would be moved to the correct location
Array(
    [0] => Array (
         [data] => <strong>First Name</strong>
    )        
    [1] => Ross
)

//in orignal: $headings['foo'] is not defined so we have no label here
//in my code: this element is removed and doesn't get rendered
Array(
     [0] => Array(
           [data] => <strong></strong>
      )

     [1] => bar
)

Sandbox (Orignal Code)

虽然这些事情可能永远不会引起问题,但它突出了我的观点,即基于而不是 $表格数据 . 事情往往会发生变化,这样如果你从这个数据中添加/删除一个字段,你就不必担心它会破坏这个页面等等。。。

数组填充键 , array_intersect_key 和 array_merge 可以用来将一个数组的头(如上图所示)映射到另一个数组。你可以用 array_combine($headings, $row) 物理交换它们,你会得到这样的结果:

[
     [
         '<strong>ID</strong>' => 102,
         '<strong>First Name</strong>' => 'Ross',
          //...
     ],
     [...]
]

它适用于CSV文件(这是我发现的)和任何其他需要重新映射密钥的文件。

不管怎样,希望对你有帮助!