Shortcode Attribute Containing Bracket Issue - wordpress

Question

The Shortcode API states that you can't have square brackets in your attribute. Thus, the following would not work:
[tag attribute="[Some value]"]
In my case, the square bracket is required. What would be the best solution of getting around this problem? I've already tried escaping the content in my shortcode function, but had no luck.
I am using WordPress 3.3.1.

Answer 1

Use some other special character in your shortcode and replace it square brackets in your shortcode function. - Since this is not what you want, here's an alternative.
This seems to be the only thing that I can think of that will work in your case, instead of relying on the Shortcode API, you can use "apply_filters" on the content, and then use preg_replace to write your own shortcode processing function.

Answer 2

If the brackets appear as part of the HTML generated try to use &#...; or as part of an URL use %... .
Otherwise, if it concerns your own shortcode, just replace some other character, e.g. {} by [], inside the code of the shortcode.
If it's not your own shortcode, you might modify the plugin / core. I'd write a wrapper code in order not to break updates.

Answer 3

We store json in shortcode attributes. We decided to use base64_encode to hide square brackets, but we faced some problems:
Themecheck complains about base64 functions
When you want to make some replace in database, for e.g. to replace all old site urls with new site url, the regex can't see what's inside a base64 encoded string
There is another solution, using htmlentities
function encode($str) {
$str = htmlentities($str, ENT_QUOTES, 'UTF-8');
// http://www.degraeve.com/reference/specialcharacters.php
$special = array(
'[' => '[',
']' => ']',
);
$str = str_replace(array_keys($special), array_values($special), $str);
return $str;
}
function decode($str) {
return html_entity_decode($str, ENT_QUOTES, 'UTF-8');
}
$original = '[1,2,3,"&",{a:1,b:2,"c":"Результат"}]';
$encoded = encode($original);
$decoded = decode($encoded);
echo "Original:\t", $original, PHP_EOL;
echo "Shortcode:\t", '[hi abc="'. $encoded .'"]', PHP_EOL;
echo "Decoded:\t", $decoded, PHP_EOL;
echo "Equal:\t\t", ($original === $decoded) ? 'YES' : 'NO';
Output
Original: [1,2,3,"&",{a:1,b:2,"c":"Результат"}]
Shortcode: [hi abc="[1,2,3,"&",{a:1,b:2,"c":"Результат"}]"]
Decoded: [1,2,3,"&",{a:1,b:2,"c":"Результат"}]
Equal: YES
http://ideone.com/fNiOkD