如何使用 PHP 获取 XML 文档上的图像元素？答案

【问题标题】：How to get image element on XML document with PHP?如何使用 PHP 获取 XML 文档上的图像元素？
【发布时间】：2018-02-20 09:27:57
【问题描述】：

我正在尝试获取缩略图链接，例如：

https://i.pinimg.com/236x/38/8f/c9/388fc91621d9d12db3d1211b39ab0fc1--flying-dog-pure-joy.jpg

但由于某种原因 getElementsByTagName 没有返回我想要的。

$newdom=new DOMDocument();
$xml=simplexml_load_file("https://www.pinterest.co.uk/sucastro/animals.rss");
$newdom->loadXML($xml);
$out=$newdom->getElementsByTagName('img');
print_r($out);

我也试过

$out=$newdom->channel->item->description->getElementsByTagName('img');

这也失败了。

SimpleXMLElement Object
(
    [@attributes] => Array
        (
            [version] => 2.0
        )

    [channel] => SimpleXMLElement Object
        (
            [title] => ANIMALS
            [link] => https://www.pinterest.com/sucastro/animals/
            [description] => SimpleXMLElement Object
                (
                )

            [language] => en-us
            [lastBuildDate] => Fri, 48 Jan 2017 33:33:33 +0000
            [item] => Array
                (
                    [0] => SimpleXMLElement Object
                        (
                            [title] => Hi ladies. Let's pin
                            [link] => https://www.pinterest.com/pin/209628557639623067/
                            [description] => <a href="/pin/209628557639623067/"><img src="https://i.pinimg.com/236x/38/8f/c9/388fc91621d9d12db3d1211b39ab0fc1--flying-dog-pure-joy.jpg"></a>Hi ladies. Let&#39;s pin GREEN AND WHITE today ❤️
                            [pubDate] => Fri, 08 Sep 2017 20:04:02 +0000
                            [guid] => https://www.pinterest.com/pin/209628557639623067/
                        )

我已经四处寻找了几个小时尝试不同的东西，但由于某种原因它仍然不起作用。

【问题讨论】：

标签： php xml rss

【解决方案1】：

你有点搞混了。您将提要放入SimpleXMLElement，然后尝试将其加载到DOMDocument。

您需要做的是获取您的SimpleXMLElement，遍历items，并获取他们的描述。请注意，您不能在此处使用 XPath 或相关（除了使其成为另一个 SimpleXMLElement）来获取 img 的来源，因为现在您只处理元素的值.

所以，你可以在这里做的是看看有没有图片，如果有，提取来源：

<?php
$newdom=new DOMDocument();
$xml=simplexml_load_file("https://www.pinterest.co.uk/sucastro/animals.rss");
foreach ($xml->channel->item as $item) {
    $desc = $item->description;
    if (preg_match("/<img src=\"(.*?)\"/i", $desc, $m)) {
        echo "Image: ".$m[1]."<br>";
    }
}

【讨论】：

【解决方案2】：

坚持使用 XML 和 XPath，这是可能的，但您必须在读取每个块时对其进行解码 - 因此它的效率不如应有的那么高。代码读取 RSS 提要，然后获取所有描述元素。

然后它对编码的 HTML 进行解码并从每个段中获取 src 属性。

<?php
error_reporting ( E_ALL );
ini_set ( 'display_errors', 1 );

libxml_use_internal_errors();
$doc = simplexml_load_file("https://www.pinterest.co.uk/sucastro/animals.rss");
$items = $doc->xpath("//item/description");
foreach ( $items as $item ) {
    $doc = new DOMDocument();
    $doc->loadHTML(html_entity_decode($item));
    $img = $doc->getElementsByTagName('img')->item(0);
    echo $img->getAttribute('src').PHP_EOL;

}

这个输出（被空格截断）...

https://i.pinimg.com/236x/38/8f/c9/388fc91621d9d12db3d1211b39ab0fc1--flying-dog-pure-joy.jpg
https://i.pinimg.com/236x/d7/1f/dc/d71fdc7f19d8c4b896840e4d8c65642f.jpg
https://i.pinimg.com/236x/94/2a/fb/942afb5bab44f6f3b4b9ea4f35690c54--national-forest-cute-photos.jpg
https://i.pinimg.com/236x/cc/3c/26/cc3c2658f23571a8eb34a0e34d71e80a--majestic-animals-lion-cub.jpg
https://i.pinimg.com/236x/98/1f/c6/981fc6e5e1e332e0067c1b6748fce20a--swan-lake-birds-.jpg
https://i.pinimg.com/236x/86/90/8d/86908dd2ce9b8c73648cdcbc5d3325e1--white-bunnies-white-rabbits.jpg
https://i.pinimg.com/236x/e0/7b/ce/e07bcea2ec026b5900afd0dc0c35ef71--autumn-leaves-west-highland-terrier.jpg
https://i.pinimg.com/236x/8f/87/e9/8f87e95b0384a0f227c9078d053cc202--new-friends-my-friend.jpgls-lion-cub.jpg
https://i.pinimg.com/236x/98/1f/c6/981fc6e5e1e332e0067c1b6748fce20a--swan-lake-birds-.jpg
https://i.pinimg.com/236x/86/90/8d/86908dd2ce9b8c73648cdcbc5d3325e1--white-bunnies-white-rabbits.jpg
https://i.pinimg.com/236x/e0/7b/ce/e07bcea2ec026b5900afd0dc0c35ef71--autumn-leaves-west-highland-terrier.jpg
https://i.pinimg.com/236x/8f/87/e9/8f87e95b0384a0f227c9078d053cc202--new-friends-my-friend.jpg

【讨论】：

【解决方案3】：

这只是从 rss 频道的描述中获取图像。

你可以试试这个：

<?php

$xml=simplexml_load_file("https://www.pinterest.co.uk/sucastro/animals.rss");
foreach ($xml->channel->item as $item) {
    preg_match('/<img.+src=[\'"](?P<src>.+?)[\'"].*>/i', $item->description, $image);
    echo($image['src']);
    echo "<br/>";
}

?>

输出：

https://i.pinimg.com/236x/38/8f/c9/388fc91621d9d12db3d1211b39ab0fc1--flying-dog-pure-joy.jpg
https://i.pinimg.com/236x/d7/1f/dc/d71fdc7f19d8c4b896840e4d8c65642f.jpg
https://i.pinimg.com/236x/94/2a/fb/942afb5bab44f6f3b4b9ea4f35690c54--national-forest-cute-photos.jpg
https://i.pinimg.com/236x/cc/3c/26/cc3c2658f23571a8eb34a0e34d71e80a--majestic-animals-lion-cub.jpg
https://i.pinimg.com/236x/98/1f/c6/981fc6e5e1e332e0067c1b6748fce20a--swan-lake-birds-.jpg
https://i.pinimg.com/236x/86/90/8d/86908dd2ce9b8c73648cdcbc5d3325e1--white-bunnies-white-rabbits.jpg
https://i.pinimg.com/236x/e0/7b/ce/e07bcea2ec026b5900afd0dc0c35ef71--autumn-leaves-west-highland-terrier.jpg
https://i.pinimg.com/236x/8f/87/e9/8f87e95b0384a0f227c9078d053cc202--new-friends-my-friend.jpg
https://i.pinimg.com/236x/5e/8f/3b/5e8f3bc079c7617d8cf3a91568f402cd--love-my-dog-puppy-love.jpg
https://i.pinimg.com/236x/9f/6a/79/9f6a7948c1cf3d1fbc067d52691bbc7d--water-fountains-bird-baths.jpg
https://i.pinimg.com/236x/07/09/d0/0709d0b16178da14facd8401a8472a3d--dachshund-humor-dapple-dachshund.jpg
https://i.pinimg.com/236x/2e/c7/af/2ec7af9628a30ec3901c3d14d2b6dc08--animal-portraits-animals-photos.jpg
https://i.pinimg.com/236x/06/2e/4b/062e4b396631ae6fc52a64c2f32d8022--cat-whiskers-exotic-cats.jpg
https://i.pinimg.com/236x/5e/5c/d6/5e5cd648d4efb29b82607445b795d357--teacups-tea-time.jpg
https://i.pinimg.com/236x/dc/30/ce/dc30ce6b41970dc93f1a3607cb48ab2a--pretty-birds-beautiful-birds.jpg
https://i.pinimg.com/236x/80/63/e1/8063e102ba108b0f6531065bdf50687c--bear-costume-the-zoo.jpg
https://i.pinimg.com/236x/c6/f3/1e/c6f31efadca1b2f71b898a85c46a6f87--baby-polar-bears-panda-bears.jpg
https://i.pinimg.com/236x/c2/13/c3/c213c317cc750ac5fef00c4ebd1a1b71--elephant-love-baby-elephants.jpg
https://i.pinimg.com/236x/49/75/d8/4975d85611c291c50db1ee57f6018bef.jpg
https://i.pinimg.com/236x/6b/cd/35/6bcd353ac7250d4159d3c74fe0d75747--beautiful-swan-beautiful-birds.jpg
https://i.pinimg.com/236x/1f/fa/4c/1ffa4c7d4f977a9c43c5655a4a3ea0ab--fox-baby-pet-fox.jpg
https://i.pinimg.com/236x/1c/9e/e1/1c9ee1aba651fde0473a4abcc8cab6c4--baby-cheetahs-travel-photography.jpg
https://i.pinimg.com/236x/fd/cd/40/fdcd40daae027c7f51298a543a015791--baby-caracal-baby-bobcat.jpg
https://i.pinimg.com/236x/cc/75/b7/cc75b77d9cea128fcab6daa1d57826af--leopard-animal-baby-leopard.jpg
https://i.pinimg.com/236x/3c/93/29/3c9329976aa40675483e026f4ac5baa6--animaux-totems-can-to.jpg

【讨论】：