code: protected Object executeEvents(final EventType _eventType,
                                     final TargetMode _targetMode)
          throws EFapsException
      {
          Object ret = null;
          if (this.fieldId > 0 && getField().hasEvents(_eventType)) {
  
              final List<EventDefinition> events = getField().getEvents(_eventType);
  
              final StringBuilder html = new StringBuilder();
              if (events != null) {
                  final Parameter parameter = new Parameter();
                  parameter.put(ParameterValues.ACCESSMODE, _targetMode);
                  parameter.put(ParameterValues.INSTANCE, this.instance);
                  parameter.put(ParameterValues.CLASS, this.classObject);
                  parameter.put(ParameterValues.UIOBJECT, this);
                  parameter.put(ParameterValues.CALL_INSTANCE, getCallInstance());
                  parameter.put(ParameterValues.REQUEST_INSTANCES, getRequestInstances());
                  if (parameter.get(ParameterValues.PARAMETERS) == null) {
                      parameter.put(ParameterValues.PARAMETERS, Context.getThreadContext().getParameters());
                  }
                  for (final EventDefinition evenDef : events) {
                      final Return retu = evenDef.execute(parameter);
                      if (retu.get(ReturnValues.SNIPLETT) != null) {
                          html.append(retu.get(ReturnValues.SNIPLETT));
                      } else if (retu.get(ReturnValues.VALUES) != null) {
                          ret = retu.get(ReturnValues.VALUES);
                          if (retu.get(ReturnValues.INSTANCE) != null) {
                              final Instance inst = (Instance) retu.get(ReturnValues.INSTANCE);
                              if (inst != null && inst.isValid()) {
                                  setInstance(inst);
                              } else {
                                  setInstance(null);
                              }
                          }
                      }
                  }
              }
              if (html.length() > 0) {
                  ret = html.toString();
              }
          }
          return ret;
      }
docs: Executes the field value events for a field.
  
  @param _eventType    type of event to be executed
  @param _targetMode   targetmode
  @throws EFapsException on error
  @return string from called field value events or <code>null</code> if no
  field value event is defined