php - simplexml_load_string 有错误？

Question

当我使用 simplexml_load_string 时，我发现一个问题，使用后丢失数据。

$xml = '<dblp>
<inproceedings key="conf/aaim/He07" mdate="2007-06-28">
<author>Dan He</author>
<title>
<i>BMA</i>
<sup>*</sup>
: An Efficient Algorithm for the One-to-Some Shortest Path Problem on Road Maps.
</title>
<pages>346-357</pages>
<year>2007</year>
<crossref>conf/aaim/2007</crossref>
<booktitle>AAIM</booktitle>
<ee>http://dx.doi.org/10.1007/978-3-540-72870-2_33</ee>
<url>db/conf/aaim/aaim2007.html#He07</url>
</inproceedings>
</dblp>';
print_r(simplexml_load_string($xml));

运行结果:

  SimpleXMLElement Object
(
    [inproceedings] => SimpleXMLElement Object
        (
            [@attributes] => Array
                (
                    [key] => conf/aaim/He07
                    [mdate] => 2007-06-28
                )

            [author] => Dan He
            [title] => SimpleXMLElement Object
                (
                    [i] => BMA
                    [sup] => *
                )

            [pages] => 346-357
            [year] => 2007
            [crossref] => conf/aaim/2007
            [booktitle] => AAIM
            [ee] => http://dx.doi.org/10.1007/978-3-540-72870-2_33
            [url] => db/conf/aaim/aaim2007.html#He07
        )

)

数据在哪里“:道路 map 上一对多最短路径问题的有效算法。”？
我希望 xml 到 array.but 数据丢失？谢谢。我想要结果:

Array
(
[0] => Array
(
    [inproceedings] =>Array
    (
        [author] => Dan He
        [title] => Array
        (
            [0] => BMA
            [2] => *
            [5] => : An Efficient Algorithm for the One-to-Some Shortest Path Problem on Road Maps.
        )

        [pages] => 346-357
        [year] => 2007
        [crossref] => conf/aaim/2007
        [booktitle] => AAIM
        [ee] => http://dx.doi.org/10.1007/978-3-540-72870-2_33
        [url] => db/conf/aaim/aaim2007.html#He07
    )

)

)

Answer 1

SimpleXMLElement 的第一条规则是:您不要 print_r() 或 var_dump() SimpleXMLElement 对象

至于为什么看不到信息，看这篇来自documentation的说明:

Note: SimpleXML has made a rule of adding iterative properties to most methods. They cannot be viewed using var_dump() or anything else which can examine objects.

要访问标题，您可以执行以下操作:

$xmlObj = simplexml_load_string($xml);
$title = (string) $xmlObj->inproceedings->title;

SimpleXMLElement 对象的属性本身就是对象，因此您需要通过在开头添加 (string) (或使用 strval() )将它们转换为字符串。现在它们的值将被转换为字符串而不是对象。

当您想要检查 SimpleXML 对象时应该使用什么？

您可以使用 IMSoP的 simplexml_dump() 和 simplexml_tree() 辅助函数。这是 project on GitHub .