ClientDataEncoder (Tapestry API - 5.7.2)

All Known Implementing Classes:

ClientDataEncoderImpl
```
public interface ClientDataEncoder
```
A service used when a component or service needs to encode some amount of data on the client as a string. The string may be a query parameter, hidden form field, or a portion of a URL. The default implementation converts the object output stream into a Base64 string. Starting in release 5.3.6, the encoded data incorporates an HMAC (hash based message authentication code) signature, as a prefix. HMAC requires a secret key, configured using the SymbolConstants.HMAC_PASSPHRASE symbol.

Since:

5.1.0.1

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`ClientDataSink`	`createSink()`	Creates a sink for client data.
`ObjectInputStream`	`decodeClientData(String clientData)`	Decodes data previously obtained from `ClientDataSink.getClientData()`.
`ObjectInputStream`	`decodeEncodedClientData(String clientData)`	Decodes client data obtained via `ClientDataSink.getEncodedClientData()`.

- Method Detail
  - createSink
```
ClientDataSink createSink()
```
    Creates a sink for client data. The sink provides an output stream and ultimately, a string representation of the data sent to the stream.
    
    Returns:
    
    a new sink
  - decodeClientData
```
ObjectInputStream decodeClientData(String clientData)
                            throws IOException
```
    Decodes data previously obtained from ClientDataSink.getClientData().
    
    Parameters:
    
    clientData - encoded client data
    
    Returns:
    
    stream of decoded data
    
    Throws:
    
    IOException - if the client data has been corrupted (verified via the HMAC)
  - decodeEncodedClientData
```
ObjectInputStream decodeEncodedClientData(String clientData)
                                   throws IOException
```
    Decodes client data obtained via ClientDataSink.getEncodedClientData().
    
    Parameters:
    
    clientData - URLEncoded client data
    
    Returns:
    
    stream of objects
    
    Throws:
    
    IOException - if the client data has been corrupted (verified via the HMAC)
    
    Since:
    
    5.1.0.4