Hi,

I've a question: why declare the specific attributes for indexing/metadata at all? I couldn't see what binds the cmf:indexable declaration to a particular adapter in the example, so I was wondering if we could do without. Suppose we had an adapter like:


<adapter
 name="NavigationProperties"
 for="IContent"
 provides="ICatalogVariables"
 factory="addNavigationProperties"
 />

where ICatalogVariables defines a single method that returns a dict of properties and values to index. (FWIW I put an implementation of this interface in the tracker a while ago (#378) plus some code to expose plone's indexing registry as this interface.) It could even define a second method that indicated the available properties.

The catalog could work out everything that provides the ICatalogVariables interface, and calculate the properties to index. It will already index/record them as metadata if they have been added as metadata/indexes in the catalog, so not sure what all this declaration really buys us.

It does get us some cool stuff if we want to automatically set up indexes using the configuration or check that indexes/metadata exist in the catalog. But wouldn't the index configuration be part of a CMFSetup profile? In which case it would start living in two places, which could get confusing. Also, wouldn't having something that sets indexes up automatically cause a conflict when you need to add a new type of index to optimise out a hotspot?

Having seen data go into the catalog, out the other side and into the bin when I've forgotten the index, some way of checking thar indexes/metadata exist would be useful. But perhaps it's preferable to log this to the event log or something, rather than add new directives? I'm not clear about what the pros and cons are of new directives vs. using code, perhaps someone with more experience has some ideas?

Anyway, just some thoughts. It would be good to really get the catalog to be a 'service' with hooks that things can register with in a simple way, rather than having to do quite so much to wire them in.

Cheers,

pete


whit wrote:
here is a sketch of how a working "indexable" configuration would look. Names subject to improvement.

------------

<configure xmlns="http://namespaces.zope.org/cmf";
           xmlns="http://namespaces.zope.org/zope";>

 <adapter
  name="SearchableText"
  for="IContent"
  provides="IIndexable"
  factory="SearchableTextExtractor"
  />

 <adapter
  name="folder_order"
  for="IContent"
  provides="ICatalogMetadata"
  factory="folderOrderCalculator"
 />

 <cmf:indexable
  for="IContent"
  attributes='SearchableText
              path
              folder_order'
  metadata='folder_order' />

 <!-- or this for interface lovers --/>

 <cmf:indexable
  for="IContent"
  attributes='IContentIndexableAttrs'
  metadata='IContentMetadataAttrs' />

</configure>

-------------

Our primary goal was is to be able to catalog non-direct
attributes as both indexes and metadata. This straight forward to accomplish.

Eventually, I think it makes sense, as content gets happily dumber, that all indexing should work this way.

For backward compatibility, a default adapter could return direct attrs from an object for indexing.

 <adapter
  provides="IDefaultIndexable, IDefaultMetadata"
  for="*"
  factory="directAttrAccess"
 />

 <cmf:indexable
  for="*"
  attributes='*'
  metadata='*' />

Ultimately, if you didn't need back compatibility, you could override like this:

 <cmf:indexable
  for="*"
  attributes='None'
  metadata='None' />

then developers could determine class by class and interface by interface (and perhaps even by event) what was called when an object is indexed, thus lowering the overhead of cataloging.

Some other niceties come to mind when thinking about this that may not be inially easily attainable; the main two are installation of indexes via configuration and the validation of index existence by the cmf:indexable handler.

I look forward to y'alls comments.

-w








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