93
Building Streams
Step 3: Replace the template source node.
Using the Data Mapping option on the pop-up menu
for the templa
te source node, click Select Replacement Node, then select the source node for
the replacement data.
Figure 5-45
Selecting a r
eplacement source node
Step 4: Check mapped fields.
In the dialog box that opens , check that the softwa r e is mapping fields
properly
from the replacement data sourc e to the stream. Any unma pped essential fields are
display ed in red. These fie lds are used in stream operations and must be replaced with a simila r
field in the new data source in or der for downstream operations to function properly. For more
informa t
ion, see the topic Examining Mapped Fields on p. 95.
After using the dialog box to ensure that all essential fields ar e properly mapped, the old data
source is disconnected and the new data source is connected to the stream using a Filter node
called Ma
p. This Filter node directs the actual m apping of field s in the stream. An Unmap Filter
node is also included on the stream canvas. The Unmap Filter node c an be used to reverse field
name mapping by adding it to the stream. It will undo the mapped fields, but note that you will
have to e
dit any downstream terminal nodes to reselect the fields and overlays.
Figure 5-46
New data source successfully mapped to the stream
