You can promote properties from several
nodes in a message flow to define a single promoted property, which applies
to all those nodes.
One example for the use of
promoting properties is for database access. If a message flow contains two
Database nodes that each refer to the same physical database, you can define
the physical database just once on the message flow by promoting the Data
Source property of each Database node to the message flow, and setting
the property at the message flow (promoted) level.
To converge multiple
node properties to a single promoted property:
- Switch to the Broker Application Development perspective.
- Open the message flow in the Message Flow editor.
- Right-click the node whose properties you want to promote, then
click Promote Property.
The Promote
Property dialog box is displayed.
- Select the property that you want to converge. The list
on the left initially shows the expanded list of all available properties
for the selected node. If you have already promoted properties from this node,
they do not appear on the left, but on the right.
The list on the left
also includes the other nodes in the open message flow. You can expand the
properties listed under each node and work with all these properties at the
same time. You do not have to close the dialog box and select another node
from the Message Flow editor to continue promoting properties.
You can
select multiple properties to promote by selecting a property, holding down
Ctrl, and selecting one or more other properties.
If
you have you selected multiple properties to converge, all the properties
that you have selected must be available for promotion. If one or more of
the selected properties is not available for promotion, the entire selection
becomes unavailable for promotion, and the Promote button
in the right pane is grayed out.
- Click the Promote button to promote the
property or properties
The Target Selection dialog box
opens:

The Target Selection dialog box displays only the valid
targets for the promotion of the previously selected property or properties
and allows you to create a new target for the promotion, such as to a new
group or to a new property.
- To converge properties from the same or different nodes in the
message flow, expand the tree and click on a property that already exists. You can rename the properties by selecting them and clicking Rename,
or by double-clicking the group or property.
- Click OK to confirm your selections.
Note: If you create a new group or property using the Target Selection
dialog box, the changes persist even if you select Cancel in
the dialog box. When the dialog box closes, groups or properties that you
have created using the Target Selection dialog box appear in the Promote properties
dialog box.
- Expand the property trees for all the nodes for which you want
to promote properties.
- Drag the first instance of the property that you want to converge
from the list on the left, and drop it onto the appropriate group in the list
on the right.
- If the group already contains one or more promoted properties, the new
property is added at the end of the group. You can rename the new property
by double-clicking the property, or by selecting the property and clicking Rename.
- If you want the promoted property to appear in a new group, drag the property
into an empty space below the existing groups to create a new group. Alternatively:
- Select the property that you want to promote, and click Promote.
The Target Selection dialog box opens.
- Click New Group, and enter the name of the new
group.
- Click OK to confirm your changes.
- If you drag the property onto an existing promoted property of a different
type, a no-entry icon is displayed and you cannot drop the property. You must
create this as a new promoted property, or drop it onto a compatible existing
promoted property. Properties must be associated with the same property editor
to be compatible. For example, if you are using built-in nodes, you can converge
only like properties (string with string, Boolean with Boolean).
If you are using user-defined nodes,
you must check the compatibility of the property editors for the properties
that you want to converge. If you have written compiler classes for a node,
you must also ensure that converged properties have the same compiler class.
- Drag all remaining instances of the property from each of the nodes
in the list on the left onto the existing promoted property. The new property
is added under the existing promoted property, and is not created as a new
promoted property.
- Click Apply to commit this change without
closing the Property Promotion dialog box. Click OK to
complete your updates and close the dialog box.
You
can also converge properties from the Promote property dialog box by dragging
the selected property or properties from the left pane of the Promote Property
dialog box to the right pane:
- Select the property that you want to promote. You can select multiple
properties to promote by selecting a property, holding down Ctrl, and selecting
one or more other properties.
- Drop the selected property or properties onto a property in the right
pane to converge related properties from the same or different nodes in the
message flow.
For example, you might want to create a single promoted property
that overrides the property on each node that defines a data source.