IMG inserting shortcode function [closed]

Question

I want to have such feature that when users post in the comment link to the image (jpg, png etc) in would have [img][/img] around it and have rel="fancybox"to open it in the modal window.

A have such code, but it's not working as expected :(

    add_filter('the_content', 'addrellightbox');
add_filter('comment_text', 'addrellightbox');
function addrellightbox($content) {
       global $post;
       $pattern ="/<a(.*?)href=('|\")(.*?).(bmp|gif|jpeg|jpg|png)('|\")(.*?)>/i";
       $replacement = '[img]<a$1href=$2$3.$4$5 rel="lightbox" title="'.$post->post_title.'"$6>[/img]';
       $content = preg_replace($pattern, $replacement, $content);
       return $content;
}

2supertrue Yeah it's good but not enough :)

Users of my blog do not want to know about [img] [/img] constructions - they only want to post image. And they are doing it with just inserting a link. And I want to show this image as it should be - clickable and with img tags.

So... Any solution?

Answer 1

You'll save a lot of trouble using Wordpress's built-in shortcode functionality. Here's the most basic possible shortcode (borrowed from Aaron), so you can see how it works.

function my_shortcode_function(){
    return date('Y');
}
add_shortcode('year', 'my_shortcode_function');

This would create a shortcode [year] that would display the current year.

To create a shortcode that wraps content like you want to wrap the image URL, you would use the $content parameter. $content gets the text in between the wrapper tags.

function img_shortcode_29252wpse($atts, $content=null){
    return <a href="' . $content . '" rel="lightbox"><img src="' . $content . '" /></a>';
}
add_shortcode('img', 'img_shortcode_29252wpse');

That would replace a code like [img]http://url.of/image.gif[/img] with an image linking to a lightbox version of itself. I'm not 100% from your question if that's what you're going for, but you can use your basic PHP and HTML to adjust the returned code to taste.

It would also be a good idea to wrap the return statement in a conditional like if isset($content) (or, better yet, a basic validation that it is an image URL) so that the shortcode only returns something if there is text inside the [img] and [/img].