Add http:// prefix to URL when missing

Question

Hello I have a very simple code

    
Website
         


        

Answer 1

I personally use this, which is partially taken from php docs

$scheme = parse_url($link, PHP_URL_SCHEME);
if (empty($scheme)) {
    $link = 'http://' . ltrim($link, '/');
}

Answer 2

Here is another example with string subtraction:

$changeLink = $myRow->site_url;
  if(substr($changeLink, 0, 7) != 'http://') {
     $changeLink = 'http://' . $changeLink;  
}

// ....

echo "<a href=\"" . $changeLink . "\" target=\"_blank\"></a>";

Answer 3

Something like this?

if (!strpos($aProfileInfo['Website'], 'http://')) {
    $aProfileInfo['Website'] = 'http://' . $aProfileInfo['Website'];
}

Answer 4

There are two ways of tackling this problem: url parsing and regular expressions.

Some will say url parsing is right, but regular expressions work just as well in this case. I like being able to have simple one-liners for things like this especially because this would be a common occurrence in template files where you may need a one-liner inside an echo statement to maintain readability.

Regular Expressions

We can do this in a single function call with preg_replace.

preg_replace('/^(?!https?:\/\/)/', 'http://', $aProfileInfo['Website'])

This uses a negative lookahead at the beginning of the string that looks for http:// or https://. If either are found, the replace doesn't happen. If they aren't found, it replaces the beginning of the string (0 characters) with http:// essentially prepending this to the string without modifying it.

In context:

<a href="'. preg_replace('/^(?!https?:\/\/)/', 'http://', $aProfileInfo['Website']).'" target="_self">
    <div class="callButton">Website</div>
</a>

URL Parsing

(parse_url($aProfileInfo['Website'], PHP_URL_SCHEME) ? '' : 'http://') . $aProfileInfo['Website']

What this does is find out if a scheme is present on the link throught parse_url($aProfileInfo['Website'], PHP_URL_SCHEME). Then using a ternary operator, it will either output '' if there was one found or 'http://' if one wasn't found. Then it appends the link onto that.

In context:

<a href="'.((parse_url($aProfileInfo['Website'], PHP_URL_SCHEME) ? '' : 'http://') . $aProfileInfo['Website']).'" target="_self">
    <div class="callButton">Website</div>
</a>

Answer 5

I believe David's answer is the proper way to do this, but it can be simplified like this:

parse_url($aProfileInfo['Website'], PHP_URL_SCHEME)==''?'http://'.$aProfileInfo['Website']:$aProfileInfo['Website']

Answer 6

You also may take into account that "http(s)" must be at the beginning of the url:

if (preg_match('/^https?:\/\//', $aProfileInfo['Website']) === 0) {
    $aProfileInfo['Website'] = 'http://'.$aProfileInfo['Website'];
}