URL Encode / Decode

[BioHazard]

Been doing some work on URLs lately. Have found the following functions for URL Encoding / Decoding quite useful. These functions will:

• Convert un-encoded URL string to its encoded representation. http://lua docs/ to http%3A%2F%2Flua%20docs%2F
• Revert URL-encoded string, back to its original unencoded form. http%3A%2F%2Flua%20docs%2F to http://lua docs/

[B]-[I]- URL Encode:[/I][/B]
function encodeChar(chr)
    return string.format("%%%X",string.byte(chr))
end
 
function encodeString(str)
    local output, sURL = string.gsub(str,"[^%w]",encodeChar)
    return output
end
 
-- Example Usage:
Debug.Clear();
Debug.ShowWindow(true);
Debug.Print(encodeString("http://lua docs/"));

[B][I]-- URL Decode:[/I][/B]
function decodeChar(hex)
    return string.char(tonumber(hex,16))
end
 
function decodeString(str)
    local output, sURL = string.gsub(str,"%%(%x%x)",decodeChar)
    return output
end

-- Example Usage:
Debug.Clear();
Debug.ShowWindow(true);
Debug.Print(decodeString("http%3A%2F%2Flua%20docs%2F"));

After searching forum to check if something like this has already been done, did find apparently that Riz had actually done a DLL for it at some stage. Mentioned here But the link to it seems to be long gone. So, fortuitously then, you won't have to mess around with String.Replace - you can just use this baby, instead. Cool bananas.

[naxo]

interesting example, you gave me an idea about a favorite folder link websites and this example could help me thanks!

[BioHazard]

Alternate version wrapped up as a single function:
Source: http://lua-users.org

[I][B]-- URL Encode:[/B][/I]
function url_encode(str)
    if (str) then
        str = string.gsub (str, "\n", "\r\n")
        str = string.gsub (str, "([^%w %-%_%.%~])",
            function (c) return string.format ("%%%02X", string.byte(c)) end)
        str = string.gsub (str, " ", "+")
    end
    return str    
end

[I][B]-- URL Decode:[/B][/I]
function url_decode(str)
    str = string.gsub (str, "+", " ")
    str = string.gsub (str, "%%(%x%x)",
        function(h) return string.char(tonumber(h,16)) end)
    str = string.gsub (str, "\r\n", "\n")
    return str
end

Example usage attached.