[Zope-CMF] Relating different objects to each other

[Phil Glaser]

Gentlemen,

Thank you very much for introdcuing me to mxmRelation. It definitely
addresses my need in the immediate term and judging from the documentation
it looks like a first class (no pun intendned) product.

Many thanks!

--Phil


>-----Original Message-----
>From: sean.upton@uniontrib.com [mailto:sean.upton@uniontrib.com]
>Sent: Saturday, October 12, 2002 7:54 PM
>To: maxm@mxm.dk; sean.upton@uniontrib.com
>Cc: StillSmallVoice@DirectvInternet.com; zope-cmf@zope.org
>Subject: RE: [Zope-CMF] Relating different objects to each other
>
>
>I like the simplicity and ease of using your mxmRelation product,
>and I like
>the idea of consolidating all relation objects into a relation folder - it
>makes a lot of sense.  I'm using this in my current projects and it works
>out well, but my requirements are growing to have more complex relationship
>management needs, unfortunately.  I want my non-technical news and content
>staff to be able to add new types of relationships arbitrarily by using a
>keyword/phrase/label to identify them.
>
>What I would like to be able to do, in my particular case, is add
>relationships that have metadata themselves, like a model ("has part" vs.
>"related"), label ("Related Images", "Yesterday's Coverage"),
>(optionally) a
>description, tie-ins to workflow via dependency tracking (if X is
>related to
>Y, and what's more, that relationship is marked as a dependency,
>hold X with
>a guard condition until Y is published, etc).  My current mode of thinking
>is that a relationship should be an available CMF content type; each single
>relationship in my complex multiple-media asset management system
>should tie
>a one-to-one relationship between objects, and provide important metadata
>and a field to determine if the relationship creates and required
>dependencies (for workflow on those objects). A CMF relationship utility
>tool should leverage the catalog to use these "managed relationships" to
>assemble lists of related content on the fly by compositing all the
>relationship objects that serve a particular object into a list of items,
>provide a list of any dependencies in or not in a particular
>workflow state,
>etc.  Said tool would likely need to prune or modify relationships for
>deleted and/or moved content.  This is obviously ambitious, and not nearly
>as turn-key as your mxmRelation product, but I'm likely to eventually go
>down this road eventually, likely soon.
>
>I'm not sure that I need new infrastructure (though I'm sure that whatever
>is created won't be perfect - obvious questions arise like "what happens
>when content moves").  With a bit of work, though, I think high-level,
>user-customizable relationship tracking could be possible in Zope2/CMF;
>hopefully, I'm right about this.
>
>Sean
>
>-----Original Message-----
>From: Max M [mailto:maxm@mxm.dk]
>Sent: Saturday, October 12, 2002 11:34 AM
>To: sean.upton@uniontrib.com
>Cc: StillSmallVoice@DirectvInternet.com; zope-cmf@zope.org
>Subject: Re: [Zope-CMF] Relating different objects to each other
>
>
>sean.upton@uniontrib.com wrote:
>> Short term: use Max M's mxmRelation product (which is not CMF specific).
>> For each type of relation, you will need to create a mxmRelation
>object in
>> the root of your CMF site,
>
>
>Just as a sidenote here on "best practice". I have found it usefull to
>have an objectmanager, or a folder, called "relations" in which I put
>all the relation objects.
>
>relations/
>     student_class
>     student_teacher
>     student_subjects
>     etc ...
>
>Also it makes it easier to delete all relations to an object when the
>object is deleted or moved, by simply:
>
>for relation in self.relations:
>     relation.delete(self)
>
>And a few other things.
>
>... cms stuff snipped ...
>
>> Long term: I'm sure that eventually, need will dictate a more scalable
>> relationship management tool in the CMF.  See thread on this in the
>archives
>> from a few days ago.
>
>
>I don't think it is possible to make it much better in Zope than is done
>by mxmRelations. The nessecary infrastructure simply isn't there
>in Zope 2.x
>
>In Z3 there will be the objecthub, which will make a relations product
>better and automate some of the things that has to be done manually now.
>But I have added code to maintain relations during a move of an object
>which is really very simple to use, and only adds a few extra lines to
>objects using it.
>
>currently mxmRelations is basically a dictionary of paths.
>
>relation = {
>     'path/to/obj1':['path/to/obj2', 'path/to/obj3'],
>     'path/to/obj2':['path/to/obj1', 'path/to/obj3'],
>     'path/to/obj3':['path/to/obj1', 'path/to/obj2'],
>}
>
>By accident this is a so called "graph" as used in AI ;-)
>
>The most obvious improvement of mxmRelations would be to convert this
>dictionary into a OOBtree structure. This will happen when I get the
>need, or when somebody sends me a patch ;-)
>
>My guess is that it would be a *very* simple change! And would make the
>product as scalable as the ZODB allows.
>
>Currently I have some thousand objects in each relation and I don't have
>performance problems. Put hundred of thousand of objects onto one and
>you could get problems. I don't know, I haven't tried :-)
>
>
>regards Max M
>
>"Skeptic Effect" or the "Randi Effect"
>When a skeptic is near, supernatural effects seem to disappear.
>
>
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