[IMPLEMENTATION] RPC PROCEDURE [ESLInterface^]ProcName [([IN] type1 paramName1[,paramName2, ...] [IN] type2 paramName3]...)]

 ;actions 

  END ProcName

[IMPLEMENTATION] RPCX PROCEDURE [ESLInterface^]ProcName [([IN] type1 paramName1[,paramName2, ...] [IN] type2 paramName3]...)]

; actions

END ProcName

The number of parameters in procedure is not limited.

Each parameter in the procedure body presents a local variable (the type and name are written in the declaration). If the keyword IN is written before the type in the declaration of the parameter, the local variable is accepted as input variable (contingent changes of its value do not influence the value of parameter after the procedure termination). Parameters with no keyword IN are input-output ones.

Procedure must be finished by the action END ProcName.

Possible types of procedure formal parameters:

Examples of individual types of formal parameters:

Using the action CALL for the calling of the procedure, a real parameter will be substituted into the formal parameter. For the formal parameter of NT type, the type conversion is executed among real > formal > real parameter. The following combinations of real parameters are admissible for individual types of formal parameters:

• Green box represents admissible combination of formal and real parameter.
• Box with the text IN specifies the need to declare formal parameter as input one (key word IN).

Operation with the real and formal parameter for calling and return from the procedure:

* only in case of the parameter IN OUT

A procedure declared with the keyword RPC may be called from other SL scripts using the remote procedure call. The types of formal parameters for RPC procedures are NT and RN.

Executing the server event (or script) is performed in one instance. Therefore simultaneous calling RPC procedure by several another events is serialized and requests are executed in sequence by means of a request queue. If a remote procedure is declared by the keyword RPCX, then all requests to execute the procedure are removed after occurring the new request. The result behaviour is, that there are not two current requests to execute the procedure declared by using the keyword RPCX. From the side of caller, request removing is the termination of the remote call with an error.

The keyword IMPLEMENTATION is used when the procedure implements some procedure from object ESL Interface. The name of proper object is stated as prefix of procedure name which is separated by character ^.

The keyword PUBLIC is used when the procedure is a part of UNIT event. This type of procedure may be called only from the script in which the given UNIT is defined (declared) (Public procedure call).

RPC procedures allow transferring data containers and handle to the database connections.

Formal parameter of procedure - NON-TYPED RECORD

The procedure add two input parameters of INT type _p1 and _p2 together. The result is saved into the input-output parameter _v of INT type. After the return from the procedure, the parameter _cc is set to the sum of values of the parameters _a and _b. The value of the parameter _a is not changed by the action (_p2 := _p2 + _p2), because _p2 is the input parameter and its changes are not to be published.

Procedures may be called recursively (procedure from procedure).

The declaration of procedure with the parameter of Structure type:

In the example, the calling CALL is performed in the following steps:

1. The evaluation of the real parameter row index (in this case 0 => the whole object value).
2. Value reading of the real parameter _arr1.
3. Change of the formal parameter size as necessary: REDIM _arr[_arr1\DIM].
4. Saving into the formal parameter: SET _arr WITH _arr1.

Return from the procedure:

1. Value reading of the formal parameter _arr.
2. The evaluation of the real parameter row index (in this case 0 => the whole object value).
3. Change of the formal parameter size as necessary: REDIM _arr1[_arr\DIM].
4. Saving into the formal parameter: SET _arr1 WITH _arr.

For calling, if no index is written besides the real parameter (structured variable or object of Structure type), the whole value is proceeded. This is also valid, if index is stated that gets value = 0 (no access to item).
Exception is the real parameter of IC_L_AT type. This is, with no index and access to the item, accepted as the reference to object of Structured variable type, not as its value. 

If procedure is called as the remote one and is not terminated in normal way, contingent input-output parameters may not be updated. Therefore if this procedure is called synchronously with the assignment, the result of the assignment is the error ERR_MISSING_RETURN.