简单的 XML 加载文件不起作用

Question

为什么这不起作用：

$url = "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20xpath%3D%22%2F%2Fmeta%22%20and%20url%3D%22http://www.cnn.com%22&format=xml&diagnostics=false";

$xml = (simplexml_load_file($url))

我收到多个错误，告诉我 HTTP 请求失败。最终我想将此文件的结果放入一个数组中，例如

描述 = CNN.com 提供最新的突发新闻等。

关键字 = CNN、CNN 新闻、CNN.com、CNN TV 等。

但这个初始阶段不起作用。有什么帮助吗？

编辑 附加信息：

错误：

warning: simplexml_load_file(http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20xpath%3D%22//meta%22%20and%20url%3D%22http://www.cnn.com%22&format=xml&diagnostics=false) [function.simplexml-load-file]: failed to open stream: HTTP request failed!
# warning: simplexml_load_file() [function.simplexml-load-file]: I/O warning : failed to load external entity "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20xpath%3D%22//meta%22%20and%20url%3D%22http://www.cnn.com%22&format=xml&diagnostics=false" 

• 来自我的 phpinfo()： allowed_url_fopen On
• PHP 版本 5.2.11
• 认为它有效 (http:// query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20xpath%3D%22//meta%22%20and%20url%3D%22http:// www.cnn.com%22&format=xml&diagnostics=false)

Answer 1

（注意：一旦找到真正的答案，答案可能就没用了...）

---

当您解决 XML 问题（继续解决它！）时，请知道您还可以以 JSON 形式获取 YQL 响应。这是一个快速示例：

$url = "http://query.yahooapis.com/v1/public/yql?q=select+%2A+"
     . "from+html+where+xpath%3D%22%2F%2Fmeta%5B%40name%3D%27"
     . "Keywords%27+or+%40name%3D%27Description%27%5D%22+and+"
     . "url%3D%22http%3A%2F%2Fwww.cnn.com%22&format=json&diagnostics=false";

// Grab YQL response and parse JSON
$json   = file_get_contents($url);
$result = json_decode($json, TRUE);

// Loop over meta results looking for what we want
$items = $result['query']['results']['meta'];
$metas = array();
foreach ($items as $item) {
    $metas[$item['name']] = $item['content'];
}
print_r($metas);

给出一个类似的数组（屏幕上的文本被截断）：

Array
(
    [Description] => CNN.com delivers the latest breaking news and …
    [Keywords] => CNN, CNN news, CNN.com, CNN TV, news, news online …
)

请注意 YQL 查询 (在控制台中尝试）与您的略有不同，以使 PHP 更简单。

Answer 2

嗯，XML 是GETable。至于有效，它缺少 ，但我认为这不是必需的。

<query xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" yahoo:count="5" yahoo:created="2010-03-09T05:09:03Z" yahoo:lang="en-US" yahoo:updated="2010-03-09T05:09:03Z" yahoo:uri="http://query.yahooapis.com/v1/yql?q=select+*+from+html+where+xpath%3D%22%2F%2Fmeta%22+and+url%3D%22http%3A%2F%2Fwww.cnn.com%22"><results><meta content="HTML Tidy for Java (vers. 26 Sep 2004), see www.w3.org" name="generator"/><meta content="1800;url=?refresh=1" http-equiv="refresh"/><meta content="CNN.com delivers the latest breaking news and information on the latest top stories, weather, business, entertainment, politics, and more. For in-depth coverage, CNN.com provides special reports, video, audio, photo galleries, and interactive guides." name="Description"/><meta content="CNN, CNN news, CNN.com, CNN TV, news, news online, breaking news, U.S. news, world news, weather, business, CNN Money, sports, politics, law, technology, entertainment, education, travel, health, special reports, autos, developing story, news video, CNN Intl" name="Keywords"/><meta content="text/html; charset=iso-8859-1" http-equiv="content-type"/></results></query><!-- total: 250 --> 

在我的本地服务器（PHP 5.3）上测试它，没有报告错误。我使用了你的源代码并且它有效。这是一个 print_r()：

SimpleXMLElement Object
(
    [results] => SimpleXMLElement Object
        (
            [meta] => Array
                (
                    [0] => SimpleXMLElement Object
                        (
                            [@attributes] => Array
                                (
                                    [content] => HTML Tidy for Java (vers. 26 Sep 2004), see www.w3.org
                                    [name] => generator
                                )

                        )

                    [1] => SimpleXMLElement Object
                        (
                            [@attributes] => Array
                                (
                                    [content] => 1800;url=?refresh=1
                                    [http-equiv] => refresh
                                )

                        )

                    [2] => SimpleXMLElement Object
                        (
                            [@attributes] => Array
                                (
                                    [content] => CNN.com delivers the latest breaking news and information on the latest top stories, weather, business, entertainment, politics, and more. For in-depth coverage, CNN.com provides special reports, video, audio, photo galleries, and interactive guides.
                                    [name] => Description
                                )

                        )

                    [3] => SimpleXMLElement Object
                        (
                            [@attributes] => Array
                                (
                                    [content] => CNN, CNN news, CNN.com, CNN TV, news, news online, breaking news, U.S. news, world news, weather, business, CNN Money, sports, politics, law, technology, entertainment, education, travel, health, special reports, autos, developing story, news video, CNN Intl
                                    [name] => Keywords
                                )

                        )

                    [4] => SimpleXMLElement Object
                        (
                            [@attributes] => Array
                                (
                                    [content] => text/html; charset=iso-8859-1
                                    [http-equiv] => content-type
                                )

                        )

                )

        )

)

我建议您对 URL 进行编码，但这已经完成了。您可以尝试使用 cURL 执行查询。