How to detect if a string is encoded with escape() or encodeURIComponent()

Question

I have a web service that receives data from various clients. Some of them sends the data encoded using escape(), while the others instead use encodeURIComponent(). Is there

Answer 1

This won't help in the server-side, but in the client-side I have used javascript exceptions to detect if the url encoding has produced ISO Latin or UTF8 encoding.

decodeURIComponent throws an exception on invalid UTF8 sequences.

try {
     result = decodeURIComponent(string);
}
catch (e) {
     result =  unescape(string);                                       
}

For example, ISO Latin encoded umlaut 'ä' %E4 will throw an exception in Firefox, but UTF8-encoded 'ä' %C3%A4 will not.

See Also

• decodeURIComponent vs unescape, what is wrong with unescape?
• Comparing escape(), encodeURI(), and encodeURIComponent()