Hi Stephen thanks for subscribing and posting,
Your rationale was very good regarding adding the extra search field, the
complete line would have to include the '__name' qualifier to avoid having
the user inputting the id of the metadata type as you correctly inferred:
{'name': u'documentmetadata__metadata_type__name', 'title':
_(u'Metadata type')},
Every double underscore on Django means 'field' and it can go on several
levels deep. Root level is 'Document' model as defined at the beginning of
the register function:
register('document', *Document*, _(u'document')
next level is '*documentmetadata*' field from the '*Document*' model which
itself is a *foreign* *key field* to the '*DocumentMetadata*' model, next
level is the '*metadata_type*' field of '*DocumentMetadata*' model which is
a *foreign* *key field* to '*MetadataType*' model, and finally '*name*' *
field* from '*MetadataType*' Model, belonging to the *DocumentMetadata*record
being found which itself belong to the '
*Document*' being returned in the search result :) Tons of fun right?! A
full SDK and Mayan internals chapter for developers is in the TO DO list
for the next version.
The development version of Mayan has already moved to a dedicated search
solution using Haystack which allows for different search backends (Sphinx,
Whoosh, etc) to be used and I believe some of those might support the type
of search string queries (AND OR < > = ) you mentioned and the end.
--Roberto
On Monday, August 20, 2012 5:00:39 PM UTC-4, Stephen Knox wrote:
>
> Hi everyone,
>
> I am new to using Mayan and this mailing list, but I am happy to have
> found something open source that really seems to meet my needs as a fairly
> lightwight open-source DMS, and can use SQLite (I'm just doing this on my
> local machine, so no real need for a complicated DB setup).
>
> I have started to upload documents, and thinking about customising etc. My
> first thought was to have functionality to bulk-add tags, and I have
> submitted a git enhancement ticket for that (
> https://github.com/rosarior/mayan/issues/31).
>
> The other thing that I thought might be a useful enhancement, at least for
> my needs, was to be able to search only certain metadata fields. For
> instance, if you had a metadata field 'Author' clearly it's useful to be
> able to search for all documents with 'Dickens' as the author. As I
> understand it, currently the metadata search just looks in the
> metadata_documentmetadata table under the value field, so doesn't relate to
> the metadata type. I know Python, but very new to Django, but I had a play
> around with the source and eventually figured out that the lines to change
> were at the bottom of the mayan/mayan/apps/documents/models.py file. I
> registered various combinations of new fields trying to get the field to
> search on the foreign key in the metadata_metadatatype table.
>
> This included adding
>
> "{'name': u'metadatatype__name', 'title': _(u'Metadata type')},
>
> to that file, which I thought would enable search on the metadatatype.
> However, I kept getting the message
>
> "Cannot resolve keyword u'metadatatype' into field. Choices are: comments,
> date_added, description, document_type, documentcheckout, documentmetadata,
> documentrenamecount, documentversion, folderdocument, id,
> indexinstancenode, queuedocument, recentdocument, tagged_items, tags, uuid"
>
> I assume these names related somehow to the document class/app somehow but
> wasn't sure how.
>
> I was able to make it work by adding:
>
> "{'name': u'documentmetadata__metadata_type', 'title': _(u'Metadata
> type')},
>
> and changing the comparison type to 'exact', but obviously this isn't
> really a solution as it relies on the user knowing the metadatatype id,
> rather than the name.
>
> So, given that I've got fairly hopelessly lost, can anyone explain what I
> was doing wrong, or why what I was trying to do is impossible? I guessed
> something to do with joining tables but my inexperience is showing.
>
> Essentially what I was looking for was something that could some something
> like the following SQL, which works:
>
> select * from metadata_documentmetadata
> where metadata_type_id = (select id from metadata_metadatatype where name
> = 'Author')
> and value like '%Dickens%'
>
> In addition, is there a wider context to this, i.e. is this something that
> has been tried / thought about before, from a functionality or UI point of
> view? Perhaps the consensus is that it isn't even necessary? What would be
> even better would be the option to search for metadata in several fields,
> i.e. author = 'Charles Dickens' and date < 1880.
>
> Any thoughts or pointers welcome.
>
> Regards
>
> Stephen Knox
>
--
