SDK Overview of Level 1

Level 1 Functions

Function Level 1	Description
_parc()	Pass a pointer to a character string
_parclen()	Length of a character string
_parcsiz()	Size of a character string passed by reference
_pards()	Pass a character pointer to a date
_parinfa()	Parameter checking of arrays
_parinfo()	Parameter checking
_parl()	Pass a logical as an integer
_parnd()	Pass a numeric as a double
_parni()	Pass a numeric as an integer
_parnl()	Pass a numeric as a long
_paro()	Pass an object pointer to an object
_parts()	Pass a character pointer to a datetime
_parys()	Pass a character pointer to a currency
_ret()	Return
_retc()	Return a character string
_retclen()	Return a character string and its length
_retds()	Return a date string
_retl()	Return an integer to a logical
_retnd()	Return a double to a numeric
_retni()	Return an integer to a numeric
_retnl()	Return a long to a numeric
_reto()	Return an object
_retts()	Return a datetime string
_retys()	Return a currency string
ALENGTH()	Number of array elements
ISARRAY()	Is parameter an array
ISCHAR()	Is parameter a character string
ISCURRENCY()	Is parameter a currency
ISDATE()	Is parameter a date
ISDATETIME()	Is parameter a datetime
ISLOG()	Is parameter a logical
ISMEMO()	Is parameter a memo
ISNUM()	Is parameter a numeric
ISOBJECT()	Is parameter an object
PCOUNT()	Number of parameters passed

Level 1 functions are used for passing parameters between the 'C' functions and Lianja. When creating a 'C' function with the API the parameters being passed should not be defined in the function name like a normal 'C' function. Instead the parameters passed are referenced with the API _par functions. Each parameter passed is referenced by specifying a number representing the ordinal position in the parameter list with the API _par function call.

For example, the following 'C' function is passed 2 parameters. The data type of each parameter is checked first with the _parinfo() function, then the value of the parameters are passed to a char with the _parc() function. Lastly the char value is then returned.

#include "lianja_api.h"
 
lianjaapi_test_function()
{
    char string1[9];
    char string2[9];
 
    if (_parinfo(1) == API_CTYPE) {
       strcpy( string1, _parc(1));
    }
    if (_parinfo(2) == API_CTYPE) {
       strcpy( string2, _parc(2));
    }
 
    _retc( string1 );
}

Values are returned using the API _ret functions. Memory variables and array elements can also be updated from within the 'C' function to store the results, see level 3.