This appears to be working correctly, but I see one little markup error:

<label><input id="hide_tags" type="checkbox" class="vertical-align:middle;"/>Hide tags</label>

class="vertical-align:middle" should be style="vertical-align:middle"

"Hide tags" should probably have a space before it too, for legibility.

(In reply to comment #2)
> This appears to be working correctly, but I see one little markup error

Oops yes thanks.
Fixed!

Patch doesn't apply - please rebase.

I noticed that you delete larger parts of the existing code, but I don't see how this is relevant for the new feature. Could you explain some?

Katrin,
The deleted code was used to hide some inputs. Now this is done through the javascript code.

Hi Jonathan - could you please fix the merge conflict with current master? I didn't want to do it wrong.

Katrin, I switch back to Signed Off. Conflicts was quite easy.
I modified the followup by replacing the vertical-align with a margin-left (vertical-align seems useless with the Bootstrap toolbar).

Lots of conflicts in koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt

QA: Looking at this one now.

QA Comment:
I have two comments. The first having more weight than the second.

If I am hiding descriptions, I am not sure what the purpose is of Hide tags in that case. If both tag and description is gone, a user cannot know what he is doing.
Note that this is possible too in current master also but only via setting both prefs to disabled (which is less likely).
IMO We should not offer to hide both labels; we are only supporting cataloging errors here ;)
I suggest to only offer Hide tags if the description is visible. 

Furtermore, I have some doubts about keeping the pref while adding the checkbox. Maybe we actually want some "staff patron cataloging preference" instead, allowing some users to have the tags and others not..

Setting this report to In Discussion. Hoping for some feedback from all involved.

(In reply to M. de Rooy from comment #22)
> QA Comment:
> I have two comments. The first having more weight than the second.
> 
> If I am hiding descriptions, I am not sure what the purpose is of Hide tags
> in that case. If both tag and description is gone, a user cannot know what
> he is doing.
> Note that this is possible too in current master also but only via setting
> both prefs to disabled (which is less likely).
> IMO We should not offer to hide both labels; we are only supporting
> cataloging errors here ;)
> I suggest to only offer Hide tags if the description is visible.

I preferred to keep existing choices instead of restricting them. But maybe you are right, it could be improved.

> Furtermore, I have some doubts about keeping the pref while adding the
> checkbox. Maybe we actually want some "staff patron cataloging preference"
> instead, allowing some users to have the tags and others not..

The pref is the default behavior, if we remove it, catalogers will have to check/uncheck the checkbox each time. Currently, Koha does not offer the possibility to have this kind of preference per patron.

Waiting for others points of view.

(In reply to Jonathan Druart from comment #23)
> The pref is the default behavior, if we remove it, catalogers will have to
> check/uncheck the checkbox each time. Currently, Koha does not offer the
> possibility to have this kind of preference per patron.

For completeness: I do not suggest to remove it on its own. I am thinking about having a patron preference controlling it, because it seems that we need something more than current functionality.

Note that we already have patron messaging preferences. You could easily have patron cataloging preferences too?

(In reply to M. de Rooy from comment #25)
> Note that we already have patron messaging preferences. You could easily
> have patron cataloging preferences too?

Yes, but it is completely out of the scope of this bug :)

I leave the "in discussion" status since there is no discussion.
Switch back to Signed Off.

Some comments on this:

1) Why not make the option "sticky" and saving the choice in a cookie? As it is currently it seems that you will have to recheck the checkbox for every new title that you catalog. It would be nice if it behaved the same as the "Show MARC tag documentation links" feature.

2) There seems to be a weird problem when switching frameworks:
- Go to cataloguing
- Create a new record based on the default framework
- Switch the framework to "Audio..."
- Switch back to default

What I had happen was that after switching the framework, I would be redirectd to the item form and an empty record was saved. I couldn't reproduce this behaviour on master without the patch applied.

3) Why not place the "Hide tags" next to "Show MARC tag documentation links"?

4) As we have a separate option to hide documentation links, I think hiding the tags should only hide the tags, but not the documentation links.

(In reply to Katrin Fischer from comment #28)
> Some comments on this:

I took all your comments into account.

Patch tested with a sandbox, by Joel Aloi <aloi54@live.fr>

Created attachment 26327 [details] [review]
[PASSED QA] Bug 9366: On cataloguing each user can easily display tags or not

If the syspref hide_marc is set to "don't display", tags are not shown
by default.
This patch adds a checkbox to hide/show tags directly on the
cataloguing page. The value is stored in a cookie.

Test plan:
Enable/disable the sysprefs hide_marc and advancedMARCeditor in order to
check if the display is according with what the user want.
Reload the page and verify the value is kept.
The first value of the cookie is retrieved from the hide_marc pref.

Bonus:
This patch removes the link "Show MARCtag documentation links" if the
syspref advancedMARCeditor is enabled.

Signed-off-by: Joel Aloi <aloi54@live.fr>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
This works as described, the editor will remember the choices
made by the cataloguer.

Passes all tests and QA script.

Notes:
- The error messages for mandatory fields upon saving only
give the tag number and not the description, so this might require
to turn back on the tag display.

- The advancedMARCeditor doesn't display the documentation links before
and after the patch was applied. I think it could still be useful for
an advanced cataloger to be able to look up information on a field quickly.

Pushed to master.  Thanks, Jonathan!