Helper functions

Path: /sdk/add_on/scripthelper/

These helper functions simplify the implementation of common tasks. They can be used as is or can serve as the starting point for your own framework.

Public C++ interface

// Compare relation between two objects of the same type.
// Uses the object's opCmp method to perform the comparison.
// Returns a negative value if the comparison couldn't be performed.
int CompareRelation(asIScriptEngine *engine, void *leftObj, void *rightObj, int typeId, int &result);
 
// Compare equality between two objects of the same type.
// Uses the object's opEquals method to perform the comparison, or if that doesn't exist the opCmp method.
// Returns a negative value if the comparison couldn't be performed.
int CompareEquality(asIScriptEngine *engine, void *leftObj, void *rightObj, int typeId, bool &result);
 
// Compile and execute simple statements.
// The module is optional. If given the statements can access the entities compiled in the module.
// The caller can optionally provide its own context, for example if a context should be reused.
int ExecuteString(asIScriptEngine *engine, const char *code, asIScriptModule *mod = 0, asIScriptContext *ctx = 0);
 
// Compile and execute simple statements with option of return value.
// The module is optional. If given the statements can access the entities compiled in the module.
// The caller can optionally provide its own context, for example if a context should be reused.
int ExecuteString(asIScriptEngine *engine, const char *code, void *ret, int retTypeId, asIScriptModule *mod = 0, asIScriptContext *ctx = 0);
 
// Format the details of the script exception into a human readable text.
// Whenever the asIScriptContext::Execute method returns asEXECUTION_EXCEPTION, the application 
// can call this function to get more information about that exception in a human readable form.
// The information obtained includes the current function, the script source section, 
// program position in the source section, and the exception description itself.
std::string GetExceptionInfo(asIScriptContext *ctx, bool showStack = false);
 
// Write registered application interface to file.
// This function creates a file with the configuration for the offline compiler, asbuild, in the samples.
// If you wish to use the offline compiler you should call this function from you application after the 
// application interface has been fully registered. This way you will not have to create the configuration
// file manually.
int WriteConfigToFile(asIScriptEngine *engine, const char *filename);
 
// Write the registered application interface to a text stream. 
int WriteConfigToStream(asIScriptEngine *engine, std::ostream &strm); 
 
// Loads an interface from a text stream and configures the engine with it. This will not 
// set the correct function pointers, so it is not possible to use this engine to execute
// scripts, but it can be used to compile scripts and save the byte code.
int ConfigEngineFromStream(asIScriptEngine *engine, std::istream &strm, const char *nameOfStream = "config", asIStringFactory *stringFactory = 0);

Example

To compare two script objects the application can execute the following code:

void Compare(asIScriptObject *a, asIScriptObject *b)
{
  asIScriptEngine *engine = a->GetEngine();
  int typeId = a->GetTypeId();
 
  int cmp;
  int r = CompareRelation(engine, a, b, typeId, cmp);
  if( r < 0 )
  {
    cout << "The relation between a and b cannot be established b" << endl;
  }
  else
  {
    if( cmp < 0 )
      cout << "a is smaller than b" << endl;
    else if( cmp == 0 )
      cout << "a is equal to b" << endl;
    else
      cout << "a is greater than b" << endl;
  }
}