Representation Status

For each server runtime type, a runtime attribute rpStatus of type integer is implicitly declared by Server. A particular feature of this attribute is that its value is defined within the scope of each view. This means that an object can have a different representation status in different views. The representation status is very useful for controlling the way each object is notified in a view. For instance, in the CompanyTree view type, the representation status can be used to expand or shrink the tree for a given Department object:

view CompanyTree:

subscribe origin Company:

represent TreeR root:

string label=identifier;

propagate departments;

subscribe Department:

represent TreeItemR item:

Ref<TreeR> ownerTree=company->root;

string label=name;

propagate employees when (rpStatus==2);

subscribe Employee:

represent TreeItemR subItem:

Ref<TreeItemR> ownerItem=department->item;

string label=name;

By default, the representation status of a server object is:

• 0 if the view does not subscribe to this object

• 1 if it does.

This means that when opening a view CompanyTree, only the list of the departments making up the company appear in the tree. If you want to expand or shrink the tree for a given department, you must change the representation status of the department. One way to do this is to have the callback function TreeItemR::onSelection called when a double-click event occurs on the tree gadget item. This function uses a new data member defined by the user on TreeItemR to locally store the last representation status set.

After updating the status, the function setRpStatus is called, as shown in the code sample below:

void TreeItemR::onSelection()

{

_rpStatus=(_rpStatus==1)?2:1;

setRpStatus(_rpStatus);

}