topic Re: Categories and Advanced Search in Alfresco Archive

Categories and Advanced Search

sacco — Mon, 19 Feb 2007 11:25:53 GMT

HiI've been looking at the implementation of Categories and, as far as I understand, the general classification with the user-visible categories is achieved by adding an aspect to a content object with a single multi-valued property which can contain references to nodes in a space of categories (ra

Re: Categories and Advanced Search

sacco — Mon, 19 Feb 2007 11:29:39 GMT

I'd contribute a patch to do this, but I first opened the Alfresco source code last night, so I don't really know my way around yet and I don't know whether the code should sit in SearchContext.java, AdvancedSearchBean.java, or a bit in each (or rather, I could patch it in SearchContext.java, but a better solution might invlove adjusting both to work together).

The pseudo-code for a quick hack might be to put something like the following into the appropriate place in
public String buildQuery()


    java.util.Arrays.sort(categories);
    preRoot = new Path(categories[0]);
    Chop this path to remove the trailing wildcards to include children, 
        leaving at most 4 (?) Path.Elements 
                ("/member" doesn't seem to be being used, here)
    Drop the tail of this Path until the third to last node is either
        not an instance of classifiable or 
        is called categoryRoot (just being careful!)
        (the path should now end at the correct top-level super-category)

    Now loop appending the path strings with 'OR' as before, but 
        check each time that the prefix of the Path matches the one found above.
    When this match fails (i.e. the prefix has changed), 
        output " ) AND ( "
        get a new preRoot by trimming the new path and continue as before.

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Re: Categories and Advanced Search

sacco — Mon, 19 Feb 2007 11:32:31 GMT

A second point about Categories is that a strict hierarchy seems unnecessarily inflexible:

There's no hierarchy which can really make sense of situations like these overlapping groupings.

A partial solution would be to allow the Associations between Categories to for a Directed Acyclic Graph (DAG).

It looks to me like almost all you would need to do would be to allow links to be made to Categories from within other Categories: given the way it's implemented (although I've only looked at a small part), the user model should be perfectly backward-compatible, and nothing else seems to need changing.
It's probably not a good idea to let Categories link into their own children, but you already have links in the system, so at the worst I'd guess there's already code available to prevent endless recursive loops.

Re: Categories and Advanced Search

sacco — Mon, 19 Feb 2007 11:33:36 GMT

Is this the right place to post this kind of stuff, or would it be better as a request on JIRA?

Re: Categories and Advanced Search

gavinc — Tue, 20 Feb 2007 08:58:08 GMT

Yes, JIRA would be better.

Re: Categories and Advanced Search

andy — Tue, 20 Feb 2007 19:17:28 GMT

Hi

Categories can be linked in to mutiple categories 🙂
It is not exposed in the UI.

Just like groups can be linked in to other groups too….but not from the UI.

Regards

Andy

Re: Categories and Advanced Search

sacco — Thu, 22 Feb 2007 12:16:43 GMT

Hi

Categories can be linked in to mutiple categories 🙂
It is not exposed in the UI.

Good, I did wonder.

The question, then, is whether the rest of the code handling categories is set up to do the right thing. I suspect that something needs to be done (perhaps it already is done) to use paths which are canonical in some sense.

i.e. if I search for items with the category 'Norway', I need to find them all independently of which path to 'Norway' was used to classify the item, or to set the search criteria.

Is this already the case?

Re: Categories and Advanced Search

sacco — Thu, 22 Feb 2007 12:18:41 GMT

Yes, JIRA would be better.

OK, I'll think about posting some of it there, then.

I didn't like to go straight there, as some of the post was about wheteher I had understood what was going on correctly.

Re: Categories and Advanced Search

alexandra — Sat, 24 Feb 2007 11:27:36 GMT

I have experience from the Documentum platform where we used the metadata features extensively. I have not been able to figure out what I can do with categories exactly yet but I am of course looking for features similar to

Document Types: Capable of holding a unique set of metadata attribute and values in dropdown/checkboxes.

Any number for metadata attributes within each DocType.

A possibilty for hiearchical metadata values allowing for doing fields selection like Continent/Country/Region or similar..

The effect of this is of course being able to do "Smart Folders" the same way as "Smart Playlists" work in iTunes (folders based on search queries)…

Can I do any of this with categories or are they just a way to choose ONE attribute per object…

Re: Categories and Advanced Search

andy — Wed, 07 Mar 2007 12:20:04 GMT

Hi

Categories are in a hierarchy. You can apply more the one category from a given classification to an object (it is a multivalued property). You can search over these. You can also define your own aspects to add new classifications - but this would not be supported in the standard UI. You can link bits of category/classification trees into others but this is not exposed in the UI.

Categories can be queried by PATH. At some point we will have query based spaces.

There is not an enum style property - this is covered via catageroies.

Hope this helps

Andy

Re: Categories and Advanced Search

alexandra — Wed, 04 Apr 2007 14:35:49 GMT

Ok I think I am beginning to grasp the idea. I have been trying to read the wiki to find how to do extensions modifications based on the text around Data Dictionary Guide for instance. However, I find it very difficult to understand what is what since there are not many concrecte examples to learn from.

I have an issue now where I need to set up Alfresco to be used as an image library. In order to do that we need some additional metadata attributes for these images like photographer, usage rights and status. Do I need to create a new content type for this or can I extend something already existing?

Further on I would of course like to expose these new attributes in the advanced search box? What file should be modified to do that?

Also, in order to have thumbnails display and a link to a low-res JPEG-image (transformed by ImageMagick?)…what would be the best approach? A new presentation template or?

Any good parts of the wiki you can guide me to?

BTW, people are used to viewing search results from Google and other where the actual search term/terms are highlighted in their context…any way of doing that in Alfresco Web Client?