MVC: Storing a model in Application

Question

Hello again,
I just found fragments in here and the weblogs on how to store a model (derived from CL_BSP_MODEL) within the application.
To clear it up: I have a model class that shall be persistent to all controllers within the session scope (so, per user). My controllers have an attrribute called APPLICATION, being of type OBJECT. But many examples talk of the interface IF_BSP_APPLICATION which I cannot find within any of my controllers. The BSP app entry itself has no pinters to classes, just base porperties and navigation mappings, so where do I find this reference to  IF_BSP_APPLICATION?
I could create a custom class to store my model, but where to create it? I have multiple controllers and want to go shure that another controller (not being a sub controller) receives the model. I have set all my ctonrollers as well as the app to session lifecycle.
It would be okay for me to pass the next controller my model, but navigation->set_parameter() cannot pass object references.
I would like to have something like this:
CTRLA:
application->set_attribute( name='model' value=me->model ).
CTRLB:
mod = application->get_attribute( name='model' ).
Where "application" is really one single instance per session for all controllers within the MVC app.
From Java I know this as request.getSession().setAttribute("model", model);
Thanks you,
Timo

Answer 1

You already have a pointer to your application in the controller class.  It is just very generic (type object).  You need to cast it into your specific object type before you can use it.
data: model1 type ref to zcl_bsp_m_mfglbl.
  data: appl type ref to zcl_ep_bsp_appl_mfglbl_prt.
****Get a Pointer to the application Object
  appl ?= application.
****Get a pointer to the Model Object.
  model1 ?= appl->model.
The reverse is true if you want to set the model into the application class.
data: model1 type ref to zcl_bsp_m_mfglbl.
****Get a pointer to the Model Object.
  model1 ?= get_model( 'MQ' ).
  if model1 is initial.
****Create the Model to hold data for the Document Search Controller
    data: model type ref to cl_bsp_model.
    model = create_model( model_id = 'MQ'
                          class_name = 'ZCL_BSP_M_MFGLBL' ).
  endif.
  data: model2 type ref to zcl_bsp_m_mfglbl.
  data: appl type ref to zcl_ep_bsp_appl_mfglbl_prt.
****Get a pointer to the Model Object.
  model2 ?= get_model( 'MQ' ).
****Get a Pointer to the application Object
  appl ?= application.
****Tell the Application object about the Model Object
  appl->model ?= model2.