Plugin conflicts with PWG stuff. When the plugin is enabled, then a personal block of PWG stuff is not visible on the page with the photo.

Hi - seems to be working on 12.1

Unfortunately, the specified support of Piwigo Version 13 does not correspond to the facts! The last version in which the plugin "User Tags" works is Piwigo in version 12.3.0. From version 13.0.0, the corresponding point is no longer displayed with the photos! It would of course be happy if it could be possible to remedy this, because this function makes it possible for my family to name events and people. This does not work in a different way, otherwise I would have to give rights that would enable a too deep interference in the database (Administration of Piwigo).

I first noticed the problem with Piwigo in version 13.2.0 because I lacked the time to take care of the photos. So I didn't know exactly since when the problem occurred and whether it might be due to a problem on the system. So yesterday I carried out a test with different versions, starting with version 2.9.5 and the same constellation - the standard theme and only the plugin "User Tags" installed, database always a new one for each version, as well as a new Piwigo directory . The standard theme has always been "Modus" since version 2.10. So at this time all versions can still continue to be called up. The test took place with version 2.9.5, 2.10.2, 11.5.0, 12.3.0, 13.0.0 and 13.4.0 - the last one was tested also with a new installation again! In all previous versions, the plugin works correctly - from version 13.0.0, the point for the tags is only displayed when a tag has already been assigned - but it is not displayed if this is not yet the case. I forgot that yesterday in the comment to mention. This means if there is no tag yet, also cannot be added a new tag via the user interface - if there is already a tag, the point appears in the user interface and another new tag can then be added too! Very strange behavior - somehow this seems to be connected with a query of existing tags.

Coming back to this since it's a new mountain biking season.
The plugin is still broken, but there is a workaround. 

Based on mpu72's comments, I went and
-dumped a .csv of my database
-pruned it down to the images in my current set
-kept two columns - the photo name, and a new column with a generic tag. 
-used the "Photo properties mass update" plugin  to apply the generic tag to all the photos in the set

Now, since those photos have a tag, the tags icon (pencil) is there and I'm able to add tags as a user.

Not the ideal solution, but it does bring the functionality back.

Piwigo 13.8.0
Theme: Smart Pocket .  Also tested in Dark, with the same result.
User Tags: 0.9.5

Either disable displaying deprecated and warning messages (because it effectively may break functionality of a page even if nothing else is broken), in local config

$conf['show_php_errors_on_frontend'] = false;

or fine tune message classes to display, see [Forum, post 183126 by erAck in topic 31852] Menubar tags issue after 12.2.0 upgrade, or better, log to file instead.
See [Forum, post 180778 by erAck in topic 31258] Error Message.

nobody_special wrote:

Have you tried initializing a tag for all your pictures?  The "Photo Properties Mass Update" plugin can be useful for this.  That should give a value to that property. 

Yes, the code should handle the case where it's undefined/null, but meanwhile there seems to be a workaround.

Thanks you for your hint! After your suggestions, I managed to solve the issue by executing the following SQL code:

insert into piwigo_image_tag (image_id , tag_id)
select img.id, 999999 from piwigo_images img
left join piwigo_image_tag tag
on img.id = tag.image_id
where tag.tag_id is null;

This SQL code identifies all images in piwigo_images that do not have tags assigned in piwigo_image_tag and inserts a new tag (with tag_id 999999) for each of those images.

Now no errors or warnings are displayed.

Apologies- my php is really rusty, so hopefully the below is reasonably coherent:

I spent a few minutes poking around, and on comparing 2 pages - one where there were tags initialized, and one where there weren't- I found this difference in the generated HTML.


Working page:
.
.
.
<form style="display:none" name="t4u-update-tags" id="t4u-update-tags" action="ws.php?format=json&method=user_tags.tags.update" method="post">
  <input type="hidden" id="t4u-image-id" name="image_id" value="196580">
  <input type="hidden" id="t4u-referer" name="referer" value="picture.php%3F%2F196580%2Fcategory%2F191">

  <select id="t4u-tags" name="tags">
    <option value="~~162~~">tag1</option>
    <option value="~~25~~">tag2</option>
    <option value="~~2914~~">tag3</option>
  </select>
  <input id="t4u-update" type="submit" disabled="disabled" class="t4u-disabled" value="Update tags">
</form>



--------------------
Non-working page
.
.
.
<form style="display:none" name="t4u-update-tags" id="t4u-update-tags" action="ws.php?format=json&method=user_tags.tags.update" method="post">
  <input type="hidden" id="t4u-image-id" name="image_id" value="124912">
  <input type="hidden" id="t4u-referer" name="referer" value="picture.php%3F%2F124912%2Fcategory%2F161">

  <select id="t4u-tags" name="tags">
<br />
<b>Warning</b>:  Undefined array key "T4U_RELATED_TAGS" in <b> ...../htdocs/piwigo/piwigo/_data/templates_c/u526d0^4303f314a4a6a6c40d2461d9c1f404cccac653dc_0.file.add_tags.tpl.php</b> on line <b>69</b><br />
<br />
<b>Warning</b>:  Attempt to read property "value" on null in <b>...../htdocs/piwigo/piwigo/_data/templates_c/u526d0^4303f314a4a6a6c40d2461d9c1f404cccac653dc_0.file.add_tags.tpl.php</b> on line <b>69</b><br />
  </select>
  <input id="t4u-update" type="submit" disabled="disabled" class="t4u-disabled" value="Update tags">
</form>

--------------------
it looks like T4U_RELATED_TAGS is used on line 21 of template/add_tags.tpl and might be initialized on line 57 of src/userTags/Content.php.

I'm guessing that the problem is really in Content.php.  If $related_tags is null because there are no existing tags, then things go sideways.