Use PHP to Convert Email Text to a Link - php

Question

Based on a question I had answered here ( Use PHP to Replace HTML with HTML ), I'd like to be able to filter my output text for email addresses, and convert those text emails to "mailto" links.
Here's the PHP code that works, but only for converting some HTML to other HTML. What I've tried to do is have this function look for an email address, and convert it to a "mailto" link. For whatever reason, the code doesn't convert the email addresses. Here's my PHP:
function text_filter($string) {
$search = array('<p>__</p>', '/[a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}/');
$replace = array('<hr />', '$2');
$processed_string = str_replace($search, $replace, $string);
echo $processed_string;
}
When I use this function for output, this is what the code looks like:
<?php text_filter( get_the_content() ); ?>

Answer 1

str_replace() doesn't use regular expressions, rewritten with preg_replace().
Added delimiters to first matching expression.
Fixed replacement from $1 to $2.
function text_filter($string) {
$search = array('/<p>__<\/p>/', '/([a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})/');
$replace = array('<hr />', '$1');
$processed_string = preg_replace($search, $replace, $string);
echo $processed_string;
}

Answer 2

#Adam Baney - This will work even when used repeatedly.
// EMAILS
$str = preg_replace('~(^|[\s\.,;\n\(])([a-zA-Z0-9._+-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})~',
'$1$2',
$str);
// PHONE NUMBERS
$str = preg_replace_callback('~(^|[\s\.,;\n\(])(?<! )([0-9 \+\(\)]{9,})~', function($m) {
return $m[1].''.$m[2].'';
}, $str);

Answer 3

You can't use str_replace to do a regular expression replace.
You will need to split the actions up.
function text_filter($string) {
$search = array('<p>__</p>');
$replace = array('<hr />');
$processed_string = str_replace($search, $replace, $string);
$processed_string = preg_replace('/[a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}/','$2',$processed_string);
echo $processed_string;
}
See: http://www.php.net/manual/en/function.preg-replace.php for preg replacing.

Answer 4

function obfuscate_email($content){
$pattern = '#([0-9a-z]([-_.]?[0-9a-z])*#[0-9a-z]([-.]?[0-9a-z])*\\.';
$pattern .= '[a-wyz][a-z](fo|g|l|m|mes|o|op|pa|ro|seum|t|u|v|z)?)#i';
$replacement = '\\1';
$content = preg_replace($pattern, $replacement, $content);
return $content;
}
And add filter
add_filter( 'the_content', 'obfuscate_email' );

Answer 5

Another way to do it in order so that it would work with existing html links in text:
function html_parse_text($text)
{
$text = preg_replace("/(?<!\")(((f|ht){1}tps?:\/\/)[-a-zA-Z0-9#:%_\+.~#?&\/\/=]+)/",
'<a href="\\1" target=_blank>\\1</a>', $text);
$text = preg_replace("/([[:space:]()[{}])(www.[-a-zA-Z0-9#:%_\+.~#?&\/\/=]+)/",
'\\1<a href="http://\\2" target=_blank>\\2</a>', $text);
$text = preg_replace("/(?<!\")([_\.0-9a-z-]+#([0-9a-z][0-9a-z-]+\.)+[a-z]{2,3})/",
'<a href="mailto:\\1" target=_blank>\\1</a>', $text);
return $text;
}

Answer 6

Here is another version of this that seems to work for me. I've added + char to handle "plus addressing" (like some+email#address.com)
function replaceemail($text) {-
$ex = "/([a-zA-Z0-9._+-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})/";
preg_match_all($ex, $text, $url);
foreach($url[0] as $k=>$v) $text = str_replace($url[0][$k], ''.$url[0][$k].'', $text);
return $text;
}