git-annex/doc/todo/wishlist:_metadata_metadata_view.mdwn

Currently looking at the metadata and views.

One of the things I would like to do is have a view that shows files by metadata metadata.. for example, "when the file last had tags changed".

Something along the lines of

    $ git annex view metadata-tag-mtime=YYYYMMDD
    view  (searching...)
    
    Switched to branch 'views/metadata/tag/mtime/YYYYMMDD'
    ok
    
    $ ls
    20130816
    20130921
    20131015

This would allow me to review files that haven't had any tag changes applied for a while and thus, may need the tags updating.

I've done this in every tagging system I've used by (ab)using mtime, but that requires an additional step (of touching the file).

> [[done]]; "$field-lastchanged" is automatically made available for each
> field! --[[Joey]]
2014-03-18 11:25:45 +00:00			`Currently looking at the metadata and views.`

			`One of the things I would like to do is have a view that shows files by metadata metadata.. for example, "when the file last had tags changed".`

			`Something along the lines of`

			`$ git annex view metadata-tag-mtime=YYYYMMDD`
			`view (searching...)`

			`Switched to branch 'views/metadata/tag/mtime/YYYYMMDD'`
			`ok`

			`$ ls`
			`20130816`
			`20130921`
			`20131015`

			`This would allow me to review files that haven't had any tag changes applied for a while and thus, may need the tags updating.`

			`I've done this in every tagging system I've used by (ab)using mtime, but that requires an additional step (of touching the file).`
Each for each metadata field, there's now an automatically maintained "$field-lastchanged" that gives the timestamp of the last change to that field. Note that this is a nearly entirely free feature. The data was already stored in the metadata log in an easily accessible way, and already was parsed to a time when parsing the log. The generation of the metadata fields may even be done lazily, although probably not entirely (the map has to be evaulated to when queried). 2014-03-18 22:55:43 +00:00
			`> [[done]]; "$field-lastchanged" is automatically made available for each`
			`> field! --[[Joey]]`