function inject_ad_text_after_n_chars($content) {
// only do this if post is longer than 1000 characters
$enable_length = 1000;
// insert after the first </p> after 160 characters
$after_character = 160;
if (is_single() && strlen($content) > $enable_length) {
$before_content = substr($content, 0, $after_character);
$after_content = substr($content, $after_character);
$after_content = explode('</p>', $after_content);
$text = '
if ( in_category( 1,3 ) ) {
$text = '<a href="http://www.misite.com/enlace" target="_blank"><img src="http://www.misite.com/banner1.jpg" alt="http://www.misite.com/banner1.jpg" /></a>';
} elseif ( in_category( 38158 ) ) {
$text = '<a href="http://www.misite.com/enlace" target="_blank"><img src="http://www.misite.com/banner2.jpg" alt="http://www.misite.com/banner2.jpg" /></a>';
} else {
$text = '<a href="http://www.misite.com/enlace" target="_blank"><img src="http://www.misite.com/banner3.jpg" alt="http://www.misite.com/banner3.jpg" /></a>';
}
';
array_splice($after_content, 1, 0, $text);
$after_content = implode('</p>', $after_content);
return $before_content . $after_content;
}
else {
return $content;
}
}