_toBase64

(As of 3.1.002.10)

Convert a string to Base64 encoding.

Syntax

_toBase64(string[, bytesperchar])

Parameters

string is the string to be converted. It must contain 8bit characters only (unicode 0-255);

bytesperchar is the coding size of each character in the string parameter. The default is 1, indicating that each string character is to be treated as a single 8bit value when it is converted. This will be mean that no character in the string is expected to have a Unicode character code greater than 255. To convert the full unicode character set, set bytesperchar to 2.

Returned Value

Returns the resulting base64-encoded string.

Example

 var str = "DocOrigin 2020";
 var b64 = _toBase64(str);	// "RG9jT3JpZ2luIDIwMjA="
 var txt = _fromBase64(b64);	// "DocOrigin 2020"

 var str2 = "保险单号";
 var b64 = _toBase64(str2, 2);	// "T92WaVNVU/c="
 var txt = _fromBase64(b64, 2);	// "保险单号"

Note that as an alternative to encoding 2-byte Unicode directly into base64, you could also convert the Unicode string to UTF-8 first. UTF-8 is a more compact representation where character codes below 128 (the ASCII set) are represented by simple single-byte characters, while others are encoded as 2 or 3 byte sequences.

The choice is dependent on your intended usage of the base64 encoded string.

 var str = "DocOrigin fête 2020";
 var utf8 = unescape(encodeURIComponent(str)); 	// "DocOrigin fête 2020"
 var b64 = _toBase64(str); 			// "RG9jT3JpZ2luIGbDqnRlIDIwMjA="
 var u = _fromBase64(b64);  			// "DocOrigin fête 2020"
 var txt = decodeURIComponent(escape(u));	// back to "DocOrigin fête 2020"

See Also

_fromBase64
_file.toBase64
_file.fromBase64