我正试图从SimpleXMLElement中找到一种对数组进行排序的方法。我想按开始时间排序，可以从event_start_dt中获得。我还想按房间ID进行排序，作为一个单独的过程。当前数组按对象（SimpleXMLElement）#排序。这是var_dump（$array）：
object(SimpleXMLElement)#275 (1) {
["reservation"]=> array(3)
{
[0]=> object(SimpleXMLElement)#287 (28) {
["reservation_id"]=> string(7) "8644894"
["event_start_dt"]=> string(25) "2013-12-02T12:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T13:00:00-08:00"
["event_id"]=> string(6) "314147"
["event_name"]=> string(24) "Practice"
["room_id"]=> string(3) "202"
}
[1]=> object(SimpleXMLElement)#288 (28) {
["reservation_id"]=> string(7) "8595185"
["event_start_dt"]=> string(25) "2013-12-02T08:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T09:00:00-08:00"
["event_id"]=> string(6) "314005"
["event_name"]=> string(24) "Meeting"
["room_id"]=> string(3) "207"
}
[2]=> object(SimpleXMLElement)#289 (28) {
["reservation_id"]=> string(7) "8718654"
["event_start_dt"]=> string(25) "2013-12-02T10:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T11:00:00-08:00"
["event_id"]=> string(6) "315811"
["event_name"]=> string(20) "Maintenance"
["room_id"]=> string(3) "202"
}
} }
我尝试过usort和asort，但都无法使用这两种方法。
usort方法：
function sortByTime($a, $b){
$a = strtotime($array->event_start_dt);
$b = strtotime($array->event_start_dt);
if ($a==$b) return 0;
return ($a < $b) ?-1 : 1;
}
usort($arrTimes, 'sortByTime');
var_dump($arrTimes);
尝试下面的代码会给我警告：usort（）要求参数1为数组，给定对象。
foreach ($rez->reservation as $value){
$var1 = $value->space_reservation->space_name;
$var2 = substr($value->event_start_dt,11,5);
}
sort_obj_arr($value,$var1,SORT_DESC);
echo "<pre>SORTED ";
print_r($value);
echo "</pre>";
function sort_obj_arr(& $arr, $sort_field, $sort_direction)
{
$sort_func = function($obj_1, $obj_2) use ($sort_field, &$sort_direction)
{
if ($sort_direction == SORT_ASC) {
return strnatcasecmp($obj_1->$sort_field, $obj_2->$sort_field);
} else {
return strnatcasecmp($obj_2->$sort_field, $obj_1->$sort_field);
}
};
usort($arr, $sort_func);
}
我的控制器中有一个数组，但无法启动：我得到：usort（）期望参数1为数组、给定对象或null。
$array = array($this->data);
print_r($array);
array(1) {
[0]=> object(SimpleXMLElement)#280 (1) { ["reservation"]=> array(3) {
[0]=> object(SimpleXMLElement)#287 (28) {
["reservation_id"]=> string(7) "8644894"
["event_start_dt"]=> string(25) "2013-12-02T12:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T13:00:00-08:00"
["event_id"]=> string(6) "314147"
["event_name"]=> string(24) "Practice"
["room_id"]=> string(3) "202"
}
[1]=> object(SimpleXMLElement)#288 (28) {
["reservation_id"]=> string(7) "8595185"
["event_start_dt"]=> string(25) "2013-12-02T08:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T09:00:00-08:00"
["event_id"]=> string(6) "314005"
["event_name"]=> string(24) "Meeting"
["room_id"]=> string(3) "207"
}
[2]=> object(SimpleXMLElement)#289 (28) {
["reservation_id"]=> string(7) "8718654"
["event_start_dt"]=> string(25) "2013-12-02T10:00:00-08:00"
["event_end_dt"]=> string(25) "2013-12-02T11:00:00-08:00"
["event_id"]=> string(6) "315811"
["event_name"]=> string(20) "Maintenance"
["room_id"]=> string(3) "202"
}
} }
请求打印_r:
SimpleXMLElement Object
(
[reservation] => Array(3)
(
[0] => SimpleXMLElement Object
(
[reservation_id] => 8604174
[event_start_dt] => 2013-12-31T06:00:00-08:00
[event_end_dt] => 2013-12-31T08:00:00-08:00
[event_id] => 314147
[event_name] => Practice
[room_id] => 202
)
[1] => SimpleXMLElement Object
(
[reservation_id] => 8604177
[event_start_dt] => 2013-12-31T05:00:00-08:00
[event_end_dt] => 2013-12-31T06:00:00-08:00
[event_id] => 314150
[event_name] => Meeting
[room_id] => 216
)
[2] => SimpleXMLElement Object
(
[reservation_id] => 8604189
[event_start_dt] => 2013-12-31T10:00:00-08:00
[event_end_dt] => 2013-12-31T11:00:00-08:00
[event_id] => 314150
[event_name] => Maintenance
[room_id] => 220
)
)
)
$arrTimes = xml2array($array->reservation);
var_dump($arrTimes)
array(5) {
["reservation_id"]=> string(7) "8604175"
["event_start_dt"]=> string(25) "2014-01-02T06:00:00-08:00"
["event_end_dt"]=> string(25) "2014-01-02T08:00:00-08:00"
["event_id"]=> string(6) "314147"
["event_name"]=> string(24) "Practice"
}
使用array_multi-sort
foreach ($rez->reservation as $value)
{
$dateTime[] = $value->event_start_dt;
}
array_multisort($dateTime,SORT_ASC,SORT_STRING,$rez->reservation);
echo "<pre>";
print_r($rez->reservation);
检查一下。这是我的代码
<?php
$myarray=array(
0 => array
(
'dateTime' => '2013-12-02T10:00:00-08:00',
'chanl1' => '20.10',
'chanl2' => '45.4',
'chanl3' => '',
),
1 => array
(
'dateTime' => '2013-12-02T11:00:00-08:00',
'chanl1' => '20.11',
'chanl2' => '45.4',
'chanl3' => '',
),
2 => array
(
'dateTime' => '2013-12-02T12:00:00-08:00',
'chanl1' => '20.12',
'chanl2' => '33.8',
'chanl3' => '',
),
3 => array
(
'dateTime' => '2013-12-02T09:00:00-08:00',
'chanl1' => '20.9',
'chanl2' => '33.9',
'chanl3' => ''
));
foreach($myarray as $c=>$key) {
$dateTime[] = $key['dateTime'];
}
array_multisort($dateTime,SORT_ASC,SORT_STRING,$myarray);
echo "<pre>";
print_r($myarray);
?>
输出为：
Array
(
[0] => Array
(
[dateTime] => 2013-12-02T09:00:00-08:00
[chanl1] => 20.9
[chanl2] => 33.9
[chanl3] =>
)
[1] => Array
(
[dateTime] => 2013-12-02T10:00:00-08:00
[chanl1] => 20.10
[chanl2] => 45.4
[chanl3] =>
)
[2] => Array
(
[dateTime] => 2013-12-02T11:00:00-08:00
[chanl1] => 20.11
[chanl2] => 45.4
[chanl3] =>
)
[3] => Array
(
[dateTime] => 2013-12-02T12:00:00-08:00
[chanl1] => 20.12
[chanl2] => 33.8
[chanl3] =>
)
)
FIDDLE
在对数据进行排序之前，您需要创建一个数组，该数组包含要排序的单独项作为其值。从调试输出来看，输入XML中有多个<reservation>节点，这些节点是这些示例中$array/$this->data表示的元素的子节点（它是否是文档的根并不重要，SimpleXML没有document对象）。
您的print_r和var_dump输出显示您当前没有这样的数组，只有一个SimpleXML对象：
- 您的第一个示例显示
var_dump($array)给出以object(SimpleXMLElement)#275 (1) {开头的输出-忽略中的单词array，这就是var_dump渲染对象内部的方式 - 稍后，您有一个以
array(1) {开头的print_r($array);，但这只是因为您已经将实际数据封装在上面一行（$array = array($this->data);）上的单个元素数组中，并且该元素（$array[0]）显示为object(SimpleXMLElement)#280 (1) { ...
请注意，无需进一步将所有内部SimpleXML对象转换为数组-您只需要一个可排序的列表，其中包含您感兴趣的项。我个人会使用一个简单而明确的foreach循环，以最大限度地提高代码可读性，尽管也有"更聪明"的解决方案。
一旦有了可排序列表，就需要usort的回调函数来比较它的两个参数。您所做的尝试是正确的，但引用了不存在的（在该函数中）变量$array；需要比较的值是函数的参数，您称之为$a和$b，特别是要比较strtotime($a->event_start_dt)和strtotime($b->event_start_dt)。
您还可以使该函数更加简单，因为它遵循了一种常见的误解，即回调的返回值应该是-1、0或1。事实上，它可以是任何整数，只有它的符号才重要——返回-42的效果与返回-999的效果相同，即在生成的数组中，将项$a放在$b之前。
我不能简单地给出一个经过测试的例子，因为您还没有提供底层的XML来重现您的输入（例如echo $this->data->asXML();），但我会采取的基本方法是：
// Start with an empty array, and add all the items we're interested in to it
$sortable_array = array();
// Loop over all <reservation> children of the SimpleXML object $this->data
// See http://php.net/manual/en/simplexml.examples-basic.php
foreach ( $this->data->reservation as $reservation_node )
{
// Add the individual node to our array
$sortable_array[] = $reservation_node;
}
// Now let's sort out the callback function for the sorting
// This could also be an anonymous function passed directly to usort
function sort_callback_event_start($a, $b)
{
// $a and $b are both items in our $sortable_array, and therefore
// <reservation> nodes which we expect to each have a child
// called <event_start_dt>
// If we convert both dates to Unix timestamps, we have two integers
// to compare, and a simple subtraction gives the desired result
// of <0, 0, or >0 as documented at http://php.net/usort
return
strtotime((string)$a->event_start_dt)
-
strtotime((string)$b->event_start_dt);
}
// Now, we have everything we need to do the actual sorting
usort($sortable_array, 'sort_callback_event_start');
// $sortable_array is now sorted as desired! :D
// Note that the items within it are still SimpleXML objects,
// so you still need to access their properties to do something useful
// e.g. some HTML output with the names listed in order of their start date:
echo '<ol>';
foreach ( $sortable_array as $reservation_node )
{
echo '<li>', (string)$reservation_node->event_name, '</li>';
}
echo '</ol>';
我会使用这个函数（php.net中的示例函数）将其强制转换为数组。但请注意，这不会对XML进行排序，而是对新数组进行排序
/**
* function xml2array
*
* This function is part of the PHP manual.
*
* The PHP manual text and comments are covered by the Creative Commons
* Attribution 3.0 License, copyright (c) the PHP Documentation Group
*
* @author k dot antczak at livedata dot pl
* @date 2011-04-22 06:08 UTC
* @link http://www.php.net/manual/en/ref.simplexml.php#103617
* @license http://www.php.net/license/index.php#doc-lic
* @license http://creativecommons.org/licenses/by/3.0/
* @license CC-BY-3.0 <http://spdx.org/licenses/CC-BY-3.0>
*/
function xml2array ( $xmlObject, $out = array () )
{
foreach ( (array) $xmlObject as $index => $node )
$out[$index] = ( is_object ( $node ) ) ? xml2array ( $node ) : $node;
return $out;
}
并将XMLObject 传递给它
$arrTimes = xml2array(YourSimpleXMLElement);
然后在新的阵列上使用您原来的usort函数
function sortByTime($a, $b){
$a = strtotime($a['event_start_dt']);
$b = strtotime($b['event_start_dt']);
if ($a==$b)
return 0;
return ($a < $b) ? -1 : 1;
}
最后
usort($arrTimes, 'sortByTime');
您必须使用json编码解码将first-in转换为xml到数组
$xml_array=json_decode（json_encode（（array）$xml），TRUE）；
u将获得数组的列表。。。。然后u可以使用strtotime函数根据日期进行排序。