RegEx和str_replace，用文本中的PHP中的其他字符串修改字符串

Question

I want to transform a certain number of characters by a string in PHP from a text :

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed fringilla tincidunt justo sed hendrerit. Vivamus [im::17,I] elit id accumsan pulvinar. Fusce ac lacus arcu. Nullam imperdiet imperdiet eros, [im::31,R] congue libero. Aliquam non bibendum nisi. Nunc pretium feugiat nunc ut volutpat. Maecenas finibus viverra justo, quis luctus [im::11,L] facilisis vel.

So what I try to do is to replace this :

[im::31,R]

By this:

<img src='img_31_0px.jpg' style='text-align:right;'/>

I got an array for the style inherit, left, right, center, this is not my difficulty.

This is my actual function:

function showimg($txtimg) {
        $fullstr = str_replace("[im::17,I]", "<img src='img_17_0px.jpg' style='text-align:inherit;'/>", $txtimg);
        return ($fullstr);
    }

As you can see, it's static for the moment, and not dynamic. I am looking on http://www.regexr.com/ to try something but it doesn't leed me anywhere.

Can you guys help me with my case, or leed me in the good direction at least? Thanks.

Answer 1

Well, to keep the alignment you'll need a callback:

function showimg($m) {
    $dir = array('I'=>'inherit','R'=>'right','L'=>'left');
    return '<img src="img_'.$m[1].'_0px.jpg" style="text-align:'.$dir[$m[2]].';"/>';
}

$result = preg_replace_callback('/\[im::([0-9]+),(I|R|L)\]/', 'showimg', $txtimg);