Trying to hack away at a Wordpress installation to add a little more user-friendliness in the comment section of a specific plugin.
Given three cases:
1
This is a sentence and image on a newline
http://imgur.com/image.gif
2
This is a sentence http://imgur.com/image.gif
3
This is a sentence and an image with IMG tags entered by user already
<img src="This is a sentence http://imgur.com/image.gif" alt="" />
When displaying these three types of comments from a user, I'd like to have PHP detect the 1st case and 1st case only - an image url on a newline (a URL that ends in common image extensions) and simply wrap it in <img> tags when displaying.
The part I'm having trouble with, given the string of the comment, how does PHP accurate detect an image link like that?
I feel like this could be accomplished with regex but I've never been terribly skilled with it? Or is it more complicated?
You can use this regex will will look at the start of each line ((?m)^), any amount of horizontal whitespace (\h*) (spaces or tabs), and then the HTTP protocol (https?://). After the protocol it takes any non-space characters (\S+?) (because URLs can't have spaces) until the allowed extension (jpe?g|gif|png|tiff|svg).
(?m)^\h*(https?://?\S+?\.(?:jpe?g|gif|png|tiff|svg))
Replace with:
<img src="$1" />