Using +ClientMessage Framework

Procedure

Create and initialize +a TClientMessageSchema structure to represent a single +message from the client.

It defines the function number corresponding +to the message, the security policy for the message, the number of paramaters +that are passed to the function and the type and constraint information for +each of the parameters.

const TParameterDetails KMessageParams2[1] = {{EParamInt,-10,100}}; + +const TClientMessageSchema KClientMessages[] = +MESSAGE_SCHEMA( EMessage0, KDefaultPolicy, KMessageParams2 );
Create and initialize +a TClientMessageServerData structure containing an array +of custom validation functionsTCustomValidationFn and TClientMessageSchema structure +defining a schema for each message that will be accepted by the server.

extern const TClientMessageServerData aServerData= + { + sizeof( KClientMessages )/sizeof( TClientMessageSchema ), + KClientMessages, + KCustomValidationFunctions, + ( TUint8* )"My Server" + }
Initialize the framework +by calling the static function CClientMessage::InitialiseFrameworkL () +and pass it to TClientMessageServerData structure.

IMPORT_C static void InitialiseFrameworkL( const TClientMessageServerData &aServerData );

Results

On construction, CMessageParameterBase objects +are instantiated using the TParameterDetails structs in the +message schema and stored in an RPointerArray. The objects +represent the individual message arguments and are used to validate each argument +against the constraints defined in the message schema.

Example

Below is an example schema that defines +four messages, including two that define custom validation functions. The +data is passed to the framework through a constant TClientMessageServerData structure.

#include <bsul/bsul.h> +using namespace BSUL; +//This enum defines the custom parameter types used to validate +//TPckg<TMyStruct> and TPckg<TMyStruct1> parameters. +enum TCustomParamType + { + EParamCustom1 = ( 0x000 | EParamPckg ), + EParamCustom2 = ( 0x100 | EParamPckg ) + }; +//Defines the schema for each message +const TParamaterDetails KMessage0Params[2] = {{EParamInt,-10,100}, + {EParamInt,0,200}}; +const TParamaterDetails KMessage1Params[2] = {{EParamDes8Read,64,64}, + {EParamInt,0,64}}; +//Parameter is TPckg<TMyStruct> +const TParamaterDetails KMessage2Params[1] = {{EParamCustom1,sizeof( TMyStruct ), sizeof( TMyStruct )}}; +//Parameter is TPckg<TMyStruct1> +const TParamaterDetails KMessage3Params[1] = {{EParamCustom2,sizeof( TMyStruct1 ), sizeof( TMyStruct1 )}}; +//Define the security policies for each message +_LIT_SECURITY_POLICY_PASS( KDefaultPolicy ); +_LIT_SECURITY_POLICY_C2( KMsg2Policy, ECapabilityReadUserData, ECapabilityWriteUserData ); +//This is the array of TClientMessageSchema structs that define the messages that will be accepted by the server. +const TClientMessageSchema KClientMessages[] = + { + {EMessage0, + KDefaultPolicy, + sizeof( KMessage0Params )/sizeof( TParamaterDetails ),KMessage0Params}, + + {EMessage1, + KDefaultPolicy, + sizeof( KMessage1Params )/sizeof( TParamaterDetails ),KMessage1Params}, + + {EMessage2, + KMsg2Policy, + sizeof( KMessage2Params )/sizeof( TParamaterDetails ),KMessage2Params}, + + {EMessage3, + KDefaultPolicy, + sizeof( KMessage3Params )/sizeof( TParamaterDetails ),KMessage3Params} + }; +//These are the custom validation functions that are used to validate +//TPckg<TMyStruct1> and TPckg<TMyStruct1> parameters +static void CustomValidationFn1L( CMessageParameterBase* aParameter ); +static void CustomValidationFn2L( CMessageParameterBase* aParameter ); +//This is the array of custom validation functions. The index of the function +//in the array should match the upper 16 bits of the value defined in +//TCustomParamType enum for that parameter type. +const TCustomValidationFn KCustomValidationFunctions[] = + { + &CustomValidationFn1L, + &CustomValidationFn2L + }; +//This is the initialization data that is passed into the ClientMessage +//framework by the server. It contains everything the framework needs to +//validate incoming messages +extern const TClientMessageServerData KServerData = + { + sizeof( KClientMessages )/sizeof( TClientMessageSchema ), + KClientMessages, + KCustomValidationFunctions, + ( TUint8* )"My Server" + };