Hi Dale, I don't think I'm in favour of link order being shown in the workspace. I really don't think that users should have to care about the order that the links are drawn, and exposing this will just increase complexity in a tool that is currently very easy to use. At least, once you manage to learn to "Think FME". If there is a setting that improves performance (such as clippers or bases first) Workbench should automatically refactor the workspace to achieve that effect. If there are cases where a user might want to override that setting, it should be through an option in the transformer, not by changing the order they draw links or add datasets to the workspace. Apart from being fragile and unobvious, a problem with ordering the datasets is that the further away from the source I get, the less sure I am that this order will be maintained. In fact, after several years of using FME I'm still not all that clear on how features move through the workspace, and it bothers me a bit that some of the really cool things that Mark and others have been able to come up with rely on this knowledge. FME has come a long way in making data translation pain-free, but there is still a bit of the "high priests of GIS" aura around understanding how it really works. GIS is rapidly moving into mainstream IT, and I believe that fostering practices which encourage this mystique is a mistake. It is tempting to just expose the complexity and allow users to deal with it, but in the end of the day I want a tool that allows me to do my job quickly and efficiently, without having to remember minutiae when I come back to it after a couple months of focussing on something else. Jason (long since assimilated) By the way, my co-workers were giving me a hard time last week because I was being more argumentative than usual. Apologies if that has come through here as well. :)
________________________________ From: Dale Lutz [EMAIL PROTECTED] Sent: Sat 2006-09-16 10:17 AM To: [email protected] Subject: RE: Order of features read -- was SpatialFilter Usage Hello Jason, others, This was a fascinating thread, filled with hockey references (and training camp is only just starting up this week!). But the root of it I think is a bit unfortunate. From what I can tell the contentious issue was about the order of features flowing into things, and the fact that if you're doing clipping or spatialfiltering, you're MUCH BETTER off if somehow you can get the clipper/filter features to arrive first than they straggle through the door at some point mid translation. So, a few comments: 1) We should emphasize this fact in the documentation for the Clipper and SpatialFilter - by way of this email I'm asking that this be done 2) We should then also give a description of how you can control the feature order in workbench - there actually is an obvious and blatant way of doing it, but folks may not know. I'll describe it below. 3) In general, the order that links are drawn shouldn't be something we'd want people to care about. That is a bit subtle, but I am willing to entertain ideas on how we could make that more explicit if people think it is useful to know/control. For example, we could have a mode where each link gets a tiny annotation number (1,2,3 etc) as it emerges from a port to tell you its order in how the feature copies will shoot out. I think we have technology to do this, probably it would be an advanced option, because again, I mostly think people shouldn't have to worry about that expect in rare cases. (I'm interested in feedback on this idea, perhaps in its own thread here on the list, or in person at the UC next week). RE: #2, the recommended way to get the clippers/filters into factories first is just to set up a reader for them, and make that reader the first reader. You can control the order that the features are read - they are read from each reader in order from top to bottom as they are listed in the navigation pane, and indeed, the writers are written to in the order they are listed in the navigation pane. You can move readers/writers up and down as need be in the navigation pane not by dragging unfortunately, but by right clicking on them and saying move up or down. If you are reading a database to get both the clippers and clippees, then use 2 readers on the same database, one choosing the clipper table, and the second one choosing the clippee table. Then the order of things is explicit and not surprising. Should we number the readers and writers in the navigation pane to drive home this point? All feedback welcomed as we, like the Borg, strive for perfection. Dale ---------------------------------------------------------------------- Dale Lutz Safe Software Inc. [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> VP Development Surrey, BC, CANADA phone: (604) 501-9985 http://www.safe.com <http://www.safe.com> fax: (604) 501-9965 ---------------------------------------------------------------------- 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/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/fme/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> 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/
