Question

I found that php preg_replace doesn’t work with HTML tag.

Let’s say I have such a code:

    $language = $this->cms_language();
    $pattern = array();
    $pattern[] = "/\{\{ if_language:$language \}\}(.*)\{\{ elif_language:.*\{\{ end_if }}/";
    $pattern[] = "/\{\{ if_language:$language \}\}(.*)\{\{ else \}\}.*\{\{ end_if }}/";
    $pattern[] = "/\{\{ if_language:.*\{\{ elif_language:$language \}\}(.*)\{\{ elif_language:.*\{\{ end_if }}/";
    $pattern[] = "/\{\{ if_language:.*\{\{ elif_language:$language \}\}(.*)\{\{ else \}\}.*\{\{ end_if }}/";
    $pattern[] = "/\{\{ if_language:.*\{\{ else \}\}(.*)\{\{ end_if }}/"; 
    $replacement = '$1';
    $value = preg_replace($pattern, $replacement, $value);

$this->cms_language() will return one of “english”, “german” or “indonesia”

When I assign such a string to $value, it will give either “Victoria”, “Hitler” or “Sule” depend on the $language’s value:

$value = '{{ if_language:english }}Victoria{{ elif_language:german }}Hitler{{ else }}Sule{{ end_if }}</p>'

But it won’t work when I change $value into

$value = '{{ if_language:english }}<br />
Victoria<br />
{{ elif_language:german }}<br />
Hitler<br />
{{ else }}<br />
Sule<br />
{{ end_if }}</p>'

The will give $value itself as the output.

So what’s wrong here?

EDIT : Sorry I found this one works:

$value = '{{ if_language:english }}<br />Victoria<br />{{ elif_language:german }}<br /> Hitler<br />{{ else }}<br />Sule<br />{{ end_if }}';

So I guess the problem is with new line character, not with the <br /> tag

Answer 1

The problem is that you’re missing the right pattern modifier.

In this case you should use the /s modifier, e.g.:

/your pattern/s

The /s modifier changes how dot . matches characters; by default it matches everything except newlines, but with /s it truly matches anything.

Btw, you may want to also use /U modifier to make the expression (.*) non-greedy by default; greedy patterns will try to match as much as possible and you may get unexpected results if you use them.

Multiple pattern modifiers are specified like this:

/your pattern/sU

Btw, instead of the /U modifier you can also use (.*?) to specify non-greedy matching.