Difference between revisions of "SDK Overview of Level 4"
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Latest revision as of 14:15, 30 March 2009
Level 4 Functions
| Function level 4 | Description |
|---|---|
| DEFINE_CLASS() | Define a class |
| DEFINE_PROPERTYGET() | Define a get property |
| DEFINE_PROPERTYSET() | Define a set property |
| DEFINE_METHOD() | Define a method |
| DISPATCH_FACTORY() | Dispatch a factory method |
| DISPATCH_PROPGET() | Dispatch a get property |
| DISPATCH_PROPSET() | Dispatch a set property |
| DISPATCH_METHOD() | Dispatch a method |
| OBJECT_ASSIGN() | Assign a new object |
| OBJECT_DELETE() | Delete an existing object |
| OBJECT_GETARG() | Get argument value |
| OBJECT_GETARGC() | Get the number of arguments |
| OBJECT_GETDATA() | Get object's data area |
| OBJECT_GETOBJECT() | Get an object |
| OBJECT_GETPARAMETER() | Get parameter value |
| OBJECT_GETPROPERTY() | Get property value |
| OBJECT_GETTYPE() | Get parameter type |
| OBJECT_GETVALUE() | Get value to set property to |
| OBJECT_NEW() | Create a new object |
| OBJECT_RETERROR() | Return error |
| OBJECT_RETPROPERTY() | Return property value |
| OBJECT_RETRESULT() | Return the value of a result |
| OBJECT_SETARG() | Set argument value |
| OBJECT_SETDATA() | Set object's data area |
| OBJECT_SETPROPERTY() | Set property value |
Macros
Level 4 DEFINE_XXX macros are used for defining classes and their associated methods that can be instantiated from the Recital 4GL. The DISPATCH_XXX macros are used to dispatch method calls in an OBJARG format to the specified methods. The OBJECT_XXX macros are use to access and return values passed to and from the object.
OBJARG
The OBJARG format is stored in a string in the format "X:ASCII" where 'X' can be any one of the following:
| TYPE | DESCRIPTION |
|---|---|
| E | Error |
| C | Character |
| N | Numeric |
| L | Logical |
| D | Date |
| T | Datetime |
| Y | Currency |
| O | Object |
OBJPTR
This macro is the pointer to an instantiated object defined by the class.
Object Data Structures
Public properties and methods need to be defined a structure for introspection called public_properties and public_methods. The structures are in an OBJARG format except for the last item which must be defined as an empty string. The string part of the OBJARG is defined as "Name;Type;Description", for example:
static char *public_properties[] = { "C:CHARVALUE;C;Character property value", "C:NUMVALUE;N;Numeric property value", "C:LOGVALUE;L;Logical property value", "C:DATEVALUE;D;Date property value", "C:TIMEVALUE;T;DateTime property value", "C:CURRVALUE;Y;Currency property value", "C:OBJVALUE;O;Object property value", "", }; static char *public_methods[] = { "C:DEFINE;L;Define settings in exception", "", };
Return codes
The macros OBJECT_ERROR and OBJECT_SUCCESS are defined to be used to return the result of a method call.
