Monitoring pipeline progress
Testing the Start function’s return
value is not the only way to monitor the status of pipeline execution.
Another technique you can use is to retrieve statistics that your
supporting user object keeps concerning the number of rows processed.
They provide a live count of:
-
The rows read by
the pipeline from the source tables -
The rows written by the pipeline
to the destination table or to the error DataWindow control -
The rows in error that the
pipeline has written to the error DataWindow control (but not to
the destination table)
By retrieving these statistics from the supporting user object,
you can dynamically display them in the window and enable users
to watch the pipeline’s progress.
To display pipeline row statistics:
-
Open your supporting user object in the
User Object painter.The User Object painter workspace displays, enabling you to
edit your user object. -
Declare three instance variables of type StaticText:
1statictext ist_status_read, ist_status_written, &1      ist_status_errorYou will use these instance variables later to hold three
StaticText controls from your window. This will enable the user
object to manipulate those controls directly and make them dynamically
display the various pipeline row statistics. -
In the user object’s PipeMeter event
script, code statements to assign the values of properties inherited
from the pipeline system object to the Text property of your three
StaticText instance variables.1ist_status_read.text    = string(RowsRead)1ist_status_written.text = string(RowsWritten)1ist_status_error.text   = string(RowsInError) -
Save your changes to the user object, then close
the User Object painter. -
Open your window in the Window painter.
-
Insert three StaticText controls in the window:
-
One to display the RowsRead
value -
One to display the RowsWritten value
-
One to display the RowsInError value
-
-
Edit the window’s Open event script (or
some other script that executes right after the window opens).In it, code statements to assign the three StaticText controls
(which you just inserted in the window) to the three corresponding
StaticText instance variables you declared earlier in the user object.
This enables the user object to manipulate these controls directly.In the sample order entry application, this logic is in a
user event named uevent_pipe_setup (which
is posted from the Open event of the w_sales_extract window):1iuo_pipe_logistics.ist_status_read =                st_status_read1iuo_pipe_logistics.ist_status_written = &1      st_status_written1iuo_pipe_logistics.ist_status_error = &1      st_status_error -
Save your changes to the window. Then close the
Window painter.When you start a pipeline in the w_sales_extract window
of the order entry application, the user object’s PipeMeter
event triggers and executes its code to display pipeline row statistics
in the three StaticText controls: