DESCRIPTIONThis filter allow you to check that you operate with valid UTF-8 data.
Usage as type specific filter is recommended.
encodeMethod always unset UTF-8 flag on the value, but if value doesn't have flag then method checks value for malformed UTF-8 data and stop on the first bad code.
decodeChecks whether value is correct UTF-8 data or not and substitute all malformed data with the 0xFFFD code point.
Always set UTF-8 flag on the value.