Hi,
you are trying an advance technique to access object members directly from C code. In particular, you assign the new created string directly to the variable name of ewJob object. Doing this in C stores just the string in the variable. When you implement such operation in Chora and then you take a look at the generated code you would see, that the simple assignment is represented by an invocation of a Runtime Environment function EwRetainString(). For example:
EwRetainString( &ewJob->name, someString )
The function EwRetainString() manages the garbage collection of strings. The usage of this function, however, is advanvce and expects a good understanding of the Embedded Wizard code generation and runtime environment. In our documentation we limit to address techniques, which are safer and more simple. These exclude the case of directly accessing the members of an object. Instead we recommend to use local variables to exchange data between Chora and native implementation.
Following could be the safer implementation of your method. Here we use 4 additional tmp variables to receive the data from the C native code. After the native statement we can evaluate the variables as usual in Chora:
/* Local variables to receive the values from 'C' native code */
var int32 tmpIndex = 0;
var string tmpName = "";
var int32 tmpTotalSteps = 0;
var int32 tmpTotalScrews = 0;
/* Native code section to initialize the tmpXXX variables */
native ( itemNo, tmpIndex, tmpName, tmpTotalSteps, tmpTotalScrews )
{
GArray* jobs = HTS_GetPtrJob();
if (itemNo < jobs->len)
{
JOB_T* job = &g_array_index(jobs, JOB_T, itemNo);
tmpIndex = job->jobIndex;
tmpName = EwNewStringAnsi( job->jobName );
tmpTotalSteps = job->totalSteps;
tmpTotalScrews = job->totalScrews;
}
}
var Application::NvcJobItem ewJob = new Application::NvcJobItem;
/* Again in Chora code it is safe to work with the local variables */
ewJob.index = tmpIndex;
ewJob.name = tmpName;
ewJob.totalSteps = tmpTotalSteps;
ewJob.totalScrews = tmpTotalScrews;
itemView.NoPP = ewJob.index;
itemView.JobNamePP = ewJob.name;
itemView.StepsPP = ewJob.totalSteps;
itemView.ScrewsPP = ewJob.totalScrews;
Since the tmp local variables are not persistent they donÄt interfer with garbage collection. It is not necessary to invoke EwRetainString() when assigning a string to a local variable.
Furthermore, in your implementation you use the object ewObj. Do you use it only to exchange data with native code? If yes, you can omit it and limit to use the tmp local variables only as demonstrated below. It makes the implementation even much more simple and faster:
/* Local variables to receive the values from 'C' native code */
var int32 tmpIndex = 0;
var string tmpName = "";
var int32 tmpTotalSteps = 0;
var int32 tmpTotalScrews = 0;
/* Native code section to initialize the tmpXXX variables */
native ( itemNo, tmpIndex, tmpName, tmpTotalSteps, tmpTotalScrews )
{
GArray* jobs = HTS_GetPtrJob();
if (itemNo < jobs->len)
{
JOB_T* job = &g_array_index(jobs, JOB_T, itemNo);
tmpIndex = job->jobIndex;
tmpName = EwNewStringAnsi( job->jobName );
tmpTotalSteps = job->totalSteps;
tmpTotalScrews = job->totalScrews;
}
}
/* Again in Chora code it is safe to work with the local variables */
itemView.NoPP = tmpIndex;
itemView.JobNamePP = tmpName;
itemView.StepsPP = tmpTotalSteps;
itemView.ScrewsPP = tmpTotalScrews;
Hope it helps you.
Best regards
Paul Banach
