[digiKam-users] Further question about saving metadata

[Chris Green]

I've started a new thread to make things (a bit) clearer.

I've been thinking about all this and it raises another quite serious
question unless I'm completely misunderstanding things.

I'm told that if I tick all the boxes under "Write This Information to
the Metadata" section of Dokuwiki's configuration settings then my
metadata will be written to the (image) files.

In that case what does the option "Write Metadata to Files" in the
Album menu do?

If ticking the boxes in the Metadata configuration means that the data
is always written to the files then what does the menu option do? Does
it just repeat the writing of the data?  Or does the data *only* get
written when you click the menu option with the Metadata configuration
settings just saying *which* metadata gets written when you click on
the Menu option?

Alternatively does clicking the Menu "Write Metadata to Files" option
write all (or some, if so which?) metadata to file regardless of the
Metadata configuration settings?


If you think carefully about this I think you will see where the
confusion is that has troubled me for so long.

--
Chris Green

[Remco Viëtor]

On jeudi 14 mai 2020 10:32:51 CEST Chris Green wrote:
> I've started a new thread to make things (a bit) clearer.
>
> I've been thinking about all this and it raises another quite serious
> question unless I'm completely misunderstanding things.
>
> I'm told that if I tick all the boxes under "Write This Information to
> the Metadata" section of Dokuwiki's configuration settings then my
> metadata will be written to the (image) files.
That seems logical. More precisely, changes for selected files will be written
on request, or when selecting another image/album. For now, let's forget about
lazy updates.

> In that case what does the option "Write Metadata to Files" in the
> Album menu do?
What it says on the box: it writes metadata to the files from the database
right now.

> If ticking the boxes in the Metadata configuration means that the data
> is always written to the files then what does the menu option do? Does
> it just repeat the writing of the data?  Or does the data *only* get
> written when you click the menu option with the Metadata configuration
> settings just saying *which* metadata gets written when you click on
> the Menu option?
Have you even done some minimal checking? I've never had to use those menu
items, *unless* a file hade been changed outside digikam. That shouldn't  
happen in my workflow, but mistakes happen (I have checking for changes on
startup activated). In all other cases I've checked, metadata were kept
synchronised between database and files (including sidecars).

> Alternatively does clicking the Menu "Write Metadata to Files" option
> write all (or some, if so which?) metadata to file regardless of the
> Metadata configuration settings?
See above...
>
> If you think carefully about this I think you will see where the
> confusion is that has troubled me for so long.

There is only confusion if you want to see things as more complicated than
written. That something is possible doesn't mean it's always needed, nor does
the presence of a manual option invalidate automatic updates. But if the
manual options are not available when they are needed, you have a *real*
problem...

You seem to think that the presence of commands to write metadata should
preclude automatic updates to file metadata. That's said nowhere in the
documentation, afaik, and in use it's easy to show that metadata *are* written
to file immediately, including to side cars. (unless lazy writing is
activated, but I do not use that, my system is fast enough that I don't need
it).

[woenx]

I believe it's redundant. It just writes the metadata to file, but manually.
In case you want to make sure it's being saved. Together with the "read
metadata from file", it's useful to refresh and sync the metadata from the
database to the pictures and vice versa.



--
Sent from: http://digikam.1695700.n4.nabble.com/digikam-users-f1735189.html

[woenx]

Just to complement my previous post, that option has been a lifesaver to me.
There were some cases where, due to a bug (now fixed), not all metadata was
being written automatically, so I had to run the "write metadata to file"
manually after doing any changes. Also, maybe you enabled the automatic
writing to metadata later on, so early files have still not been modified
with the new metadata. That option lets you manually select the files and
force-write the metadata to them, so you can make sure they are up to date.



--
Sent from: http://digikam.1695700.n4.nabble.com/digikam-users-f1735189.html

[Chris Green]

On Thu, May 14, 2020 at 11:21:36AM +0200, Remco Viëtor wrote:

> On jeudi 14 mai 2020 10:32:51 CEST Chris Green wrote:
> > I've started a new thread to make things (a bit) clearer.
> >
> > I've been thinking about all this and it raises another quite serious
> > question unless I'm completely misunderstanding things.
> >
> > I'm told that if I tick all the boxes under "Write This Information to
> > the Metadata" section of Dokuwiki's configuration settings then my
> > metadata will be written to the (image) files.
> That seems logical. More precisely, changes for selected files will be written
> on request, or when selecting another image/album. For now, let's forget about
> lazy updates.
>
> > In that case what does the option "Write Metadata to Files" in the
> > Album menu do?
> What it says on the box: it writes metadata to the files from the database
> right now.
>

So what data does it write?  Does it write all the metadata or only
the items specified in the Metadata configuration settings?

> > If ticking the boxes in the Metadata configuration means that the data
> > is always written to the files then what does the menu option do? Does
> > it just repeat the writing of the data?  Or does the data *only* get
> > written when you click the menu option with the Metadata configuration
> > settings just saying *which* metadata gets written when you click on
> > the Menu option?
> Have you even done some minimal checking? I've never had to use those menu
> items, *unless* a file hade been changed outside digikam. That shouldn't  
> happen in my workflow, but mistakes happen (I have checking for changes on
> startup activated). In all other cases I've checked, metadata were kept
> synchronised between database and files (including sidecars).
>

So if I change a file's metadata outside Digikam and then start
Digikam and click the option "Write Metadata to File" what happens?
It seems to me likely that Digikam will overwrite the change I have
made because it won't be in Digikam's database.  ...  or will Digikam
have updated its metadata when it loaded (hopefully it will do this)
and then ....  do what?  Nothing I suspect/hope.

--
Chris Green