Hi Simon,

You can use a FeatureMerger to perform a join between the filtered
outputs.  Instead of re-reading the data, you can just run your
RoadNodes into the FeatureMerger as the Requestor, and RoadLinks as the
Supplier.  You may need to do this twice; once with the to-node, and
once with the from-node.

I don't think that you can count on any of the output feature types
being written at any point in the translation until the final write.  At
that point, the output is written one data set at a time, top to bottom
as they appear in the "workspace" window.  Feature types within a data
set do not have an order of operations.  I've often had to set up
multiple data sets pointing to the same source so that I could populate
lookup tables before populating the tables with FK's pointing into them.

Jason

-----Original Message-----
From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of
jusiheap
Sent: Wednesday, July 05, 2006 05:32
To: [email protected]
Subject: [fme] Order of translation

1. When FME runs a translation, does it execute each transformation
sequentially within the workspace such that one transformation is
completed before the next is started? If so, what is the order and do I
have any control over it (unless it's simply a case of left-
>right, top->bottom of the workspace canvas)?

2. If there is such a thing as guaranteed order, presumably it's
possible to use the output from an earlier transformation as (part
of) the input to another transformation? Let me explain what I'm
after:

Translating from GML to Oracle, I'm translating the RoadNode features
into a NODES table and the RoadLink features into a LINKS table. Each
RoadLink feature is delimited by two RoadNode features; thus each
RoadLink has two attributes to hold the ids of its endpoint nodes. I'm
filtering the transformation of the RoadLink features to only allow
through those of type "motorway". I would like to filter the RoadNode
features similarly, i.e. only allow through those nodes which happen to
be endpoints for motorway links. 
Such a filter will need to straddle the RoadNode & RoadLink information.
In SQL terms, I need to use some kind of JOIN, but I don't know whether
this can be done based upon the source features/data only or whether I
have to use the (filtered) contents of my LINKS table - in which case I
have to guarantee the LINKS table is fully populated before I apply such
a join.

Cheers
Simon




Join us at the FME Worldwide User Conference Sept. 21-22, 2006 Vancouver BC 
Canada. For more information, visit www.safe.com/2006uc.   
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/fme/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply via email to