Creating Callable Objects

Use

You can implement your own callable objects with the GP design time API. The interface allows you to define input, output and configuration parameters for the callable object, as well as result states and exceptions.

Prerequisites

Callable object types are resolved with the IGPCallableObjectTypeManager . Types are defined by a type name. You can retrieve the type, if you know the type name. For example, type name com.sap.gp.wd corresponds to type Web Dynpro Application.

Procedure

  1. Create the callable object by providing its basic data:

You need to specify a category for the newly-created callable object. For this purpose, you can create a new category or provide the Id of an existing one.

Creating a Callable Object of Type Web Dynpro Application 
importjava.util.Locale;
importcom.sap.caf.eu.gp.process.dt.api.IGPDesigntimeUpdateManager;
importcom.sap.caf.eu.gp.process.dt.api.IGPDesigntimeManager;
importcom.sap.caf.eu.gp.process.api.IGPCategory;
importcom.sap.caf.eu.gp.process.api.GPProcessFactory;
importcom.sap.caf.eu.gp.co.type.api.IGPCallableObjectTypeManager;
importcom.sap.caf.eu.gp.co.type.api.IGPCallableObjectType;
importcom.sap.caf.eu.gp.co.api.IGPCallableObject;
importcom.sap.caf.eu.gp.exception.api.GPBaseException;
 
Localelocale = Locale.getDefault();
 
// get user info
IUserloggedUser = WDClientUser.getCurrentUser().getSAPUser();
IGPUserContext userContext = GPContextFactory.getContextManager().createUserContext(loggedUser);
// instantiate the design time update manager
..
// find category "test" in the root category
String catName ="test";
IGPCategory cat =null;
IGPDesigntimeManagerdtManager = GPProcessFactory.getDesigntimeManager();
IGPCategoryroot = dtManager.getRootCategory(userContext);
IGPCategory[]subs = root.getSubCategories();
for(int i = 0; i < subs.length; i++) {
   if (subs[i].resolveTitle(locale).equals(catName)) {
      cat = subs[i];
   }
}
StringcoTitle = "Title";
StringcoDescription = "Description";
StringcoType = "com.sap.gp.wd";
 
try{
   // resolve the callable object type
   IGPCallableObjectTypeManagercoTypeManager =  GPCallableObjectTypeFactory.getCallableObjectTypeManager();
   IGPCallableObjectType wdCoType = coTypeManager.getCallableObjectType(coType);
   // create the callable object      
   IGPCallableObject co = manager.createCallableObject(
            wdCoType,
            locale,
            coTitle,
            coDescription,
            cat.getID()
            );
    }catch (GPBaseException e) {
       // handle GP exception
    }
  1. Populate the input and output parameter structures of the object as they are empty initially. You may create additional attributes and substructures and specify their type and multiplicity.

    The following types of multiplicity are supported:

    Singleton 0_1 (at most one)
    1_1 (exactly one)
    List

    0_N (any number of occurrences)

    1_N (at least one)

Populating the Input Parameters Structure 
importcom.sap.caf.eu.gp.structure.api.IGPStructureInfo;
importcom.sap.caf.eu.gp.structure.api.IGPAttributeInfo;
importcom.sap.caf.eu.gp.exception.api.GPEngineException;
importcom.sap.caf.eu.gp.exception.api.GPInvocationException;
 
try{
     // obtain copy of the input parameter structure of our object 
     IGPStructureInfo input = co.getInputParameters();
     
     IGPAttributeInfo attr = null;
     // add attribute of type date, its multiplicity is by default 0_1
     attr = input.addAttribute("param_input_date", IGPAttributeInfo.BASE_DATE);
     
     // define string attribute and make it required
     attr = input.addAttribute("param_input_string", IGPAttributeInfo.BASE_STRING);
     attr.setMultiplicity(IGPAttributeInfo.MULITIPLICITY_1_1);
     
     // define a list of doubles
     attr = input.addAttribute("param_input_double", IGPAttributeInfo.BASE_DOUBLE);
     attr.setMultiplicity(IGPAttributeInfo.MULITIPLICITY_0_N);
    
     //define a substructure
     IGPStructureInfo subStruct = input.addStructure("sub_structure");
     // additionally define the substructure...
     
     // at the end, save the changes
     co.setInputParameters(input);
     
   } catch (GPEngineException e) {
     // internal exception occurred when getting or setting the input parameters
   } catch (GPInvocationException e) {
     // invalid parameters were passed by defining attribute or sub-structure
   }

You may use the same logic to populate the output parameters structure:

// obtain copy of the output parameter structure
IGPStructureInfooutput = co.getOutputParameters();
// add substructures and attributes
...
// save the changes
co.setOutputParameters(output);
  1. Depending on the particular implementation, specify additional properties.

    To define result states, exceptions and other configuration parameters, use the IGPPhysicalCallableObject associated with the callable object.

The physical callable object stores technical information about the object that should be invoked during action execution. This includes:

  • Possible result states and process exceptions resulting from the object execution
  • Information about the UI behavior of the callable object in GP design time, such as visibility of the different configuration screens

Defining Result States, Exceptions and Configuration Properties 
importcom.sap.caf.eu.gp.co.api.IGPPhysicalCallableObject;
 
IGPPhysicalCallableObjectpco = co.resolvePhysicalCallableObject();
try{
     // set two result states: complete and incomplete
     pco.addResultState("COMPLETE", "complete");
     pco.addResultState("INCOMPLETE", "incomplete");
     
     // define an exception
     pco.addProcessException("EXCEPTION", "exception");
     
     // set configuration property
     pco.setConfigProperty("property", "value");
     
    // make the input view of the object visible when the object is created, edited and displayed (for all purposes)
    pco.setInputViewVisible(true,VIEW_VISIBILITY_PURPOSE_ALL);
 
   } catch (GPInvocationException e) {
     // invalid parameters were passed
   }
  1. Save and release the object.

    Once a new callable object has been created, it is locked for editing by other users until it has been saved and released.

Saving and Releasing a Callable Object 
IGPCallableObjectco = null;
try{
   // open callable object or create a new one
   ...     
   // make some changes...
   ...     
   // save it
   manager.save(co);
}catch (GPBaseException e) {
// handle error
}
finally{
   if (co != null) manager.release(co);

}

Result

Once you have created a callable object, you can: