正则表达式以查找链接到图像的定位标记 [英] Regex to find anchor tags that link to an image

问题描述

我在WordPress主题functions.php中使用此代码向链接的图像添加"fancybox"类.但是，我不想要向链接到非图像URL的图像添加fancybox类.

I'm using this code in my WordPress theme functions.php to add a "fancybox" class to linked images. However, I do not want to add the fancybox class to images that are linked to non-image URLs.

换句话说:当前，脚本会将"fancybox"类添加到这样的HTML结构中(我不想要):

In other words: currently the script will add the "fancybox" class to an HTML structure like this (which I do not want):

< a href ="http://acme.com/a-non-image-link">< img src ="http://acme.com/image.jpg"/></a>

我只想将类添加到以下结构中:

Where as I only want to add the class to structures like:

< a href ="http://acme.com/an-image.jpg">< img src ="http://acme.com/an-image.jpg"/></a>

或

< a href ="http://acme.com/an-image.jpg">< img src ="http://acme.com/another-image.jpg"/></a>

如何在此代码中修改正则表达式，使其仅包含其HREF属性包含 .jpg ， .jpeg ， .png 或 .gif ?

How can I modify the regex expression in this code to only include anchor tags whose HREF attribute contains .jpg, .jpeg, .png, or .gif?

谢谢！

        // Add fancybox class to linked images
        function add_classes_to_linked_images($html) {
            $classes = 'fancybox fancybox-img'; // can do multiple classes, separate with space

            $patterns = array();
            $replacements = array();

            $patterns[0] = '/<a(?![^>]*class)([^>]*)>\s*<img([^>]*)>\s*<\/a>/'; // matches img tag wrapped in anchor tag where anchor tag where anchor has no existing classes
            $replacements[0] = '<a\1 class="' . $classes . '"><img\2><span class="post-content-fb-btn"></span></a>';

            $patterns[1] = '/<a([^>]*)class="([^"]*)"([^>]*)>\s*<img([^>]*)>\s*<\/a>/'; // matches img tag wrapped in anchor tag where anchor has existing classes contained in double quotes
            $replacements[1] = '<a\1class="' . $classes . ' \2"\3><img\4> <span class="post-content-fb-btn"></span></a>';

            $patterns[2] = '/<a([^>]*)class=\'([^\']*)\'([^>]*)>\s*<img([^>]*)>\s*<\/a>/'; // matches img tag wrapped in anchor tag where anchor has existing classes contained in single quotes
            $replacements[2] = '<a\1class="' . $classes . ' \2"\3><img\4> <span class="post-content-fb-btn"></span></a>';

            $html = preg_replace($patterns, $replacements, $html);

            return $html;
        }

        add_filter('the_content', 'add_classes_to_linked_images', 100, 1);

推荐答案

以下内容应适用于一个警告.链接必须在图像标签的单独一行上，否则图像的文件扩展名将创建一个匹配项.

The following should work with one caveat. The link needs to be on a separate line to the image tag, or the file extension of the image will create a match.

/<a(.*?)href=('|\")(.*?).(bmp|gif|jpeg|jpg|png)('|\")(.*?)>/i

也许有人可以改进它，而不是发布讽刺评论:)

Maybe someone can improve on it rather than posting sarcastic comments :)

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