The plugin does not add the reference data in the crossref XML file

[leocsilva]

Describe the bug
The plugin was installed and enabled in a journal. The scheduled task was set to run daily. When exporting the Crossref XML of an article that contains citations, the citations are not added to XML file.

To Reproduce
Steps to reproduce the behavior:

1 - Enable crossrefReferenceLinking

2 - Go to DOIs menu, select the article (https://seer.ufu.br/index.php/campoterritorio/article/view/78378/version/80109). Click Bulk Actions and select Export DOIs

3 - Generated file:

crossrefplugin-20250829-082900-articles-43.xml

What application are you using?
OJS 3.4.0-8
crossrefReferenceLinking 2.0.0-0

Additional information
I examined the plugin's source code. The list of citations should be added when the "articlecrossrefxmlfilter::execute" hook is called. However, I didn't find any other part of OJS that calls this hook.

[bozana]

Hi @leocsilva, just to double check: you have entered the references into the metadata Reference text area, and you can see the references for the article/publication in your DB table citations?

[leocsilva]

Hi @leocsilva, just to double check: you have entered the references into the metadata Reference text area, and you can see the references for the article/publication in your DB table citations?

Hi @bozana ,

Metadata Reference:

Citations table:

[bozana]

Hi @leocsilva,
Hmmm... very strange... I could not reproduce it. Locally I have the latest stable-3_4_0 branch and when I export the Crossref XML the citations are included. Hmmm... 🤔
That hook articlecrossrefxmlfilter::execute is called here: https://github.com/pkp/pkp-lib/blob/stable-3_4_0/classes/filter/Filter.php#L501, when plugins/generic/crossref/filter/ArticleCrossrefXmlFilter::execute() is called here https://github.com/pkp/ojs/blob/stable-3_4_0/classes/plugins/PubObjectsExportPlugin.php#L486.
I need to think why this would not work for you... Maybe you are able to debug it?

[leocsilva]

After debugging a bit, I discovered that the hasCrossrefCredentials method is returning false because the PluginRegistry::getPlugin('generic', 'crossrefplugin') call is returning NULL. Any ideas?
EDIT
PluginRegistry::getPlugin('generic', 'crossrefplugin') is probably being called before the crossref plugin is registered.

[bozana]

Hmmm... If you would add these lines:

        if ($crossrefPlugin === null) {
            PluginRegistry::register('importexport', new CrossrefPlugin($this), $this->getPluginPath());
            $crossrefPlugin = PluginRegistry::getPlugin('generic', 'crossrefplugin');
        }

after this line: https://github.com/pkp/crossrefReferenceLinking/blob/stable-3_4_0/CrossrefReferenceLinkingPlugin.php#L90
Does this solve the problem?

[leocsilva]

This line
PluginRegistry::register('importexport', new CrossrefPlugin($this), $this->getPluginPath());

throws PHP Fatal error: Uncaught Error: Class "APP\plugins\generic\crossrefReferenceLinking\CrossrefPlugin" not found in /home/portal-periodicos/releases/52/htdocs/plugins/generic/crossrefReferenceLinking/CrossrefReferenceLinkingPlugin.php:91

So I ran the following test:
public function hasCrossrefCredentials(int $contextId): bool {
return true;
}

The citations were added to the XML file.

[bozana]

Hi @leocsilva ,

Actually, first all generic plugins are loaded/registered, and then that function in CrossrefReferencePlugin is called. Also, it cannot be that CrossrefPlugin is not loaded/registered, because you are exporting an article in Crossref format, which requires the plugin to be there.
Thus, maybe you have not added Crossref username and password -- which are required for that function -- and that is why this function hasCrossrefCredentials returns false. Could you please double check if there are username and password under Settings > Distribution > DOIs > Registration?

[leocsilva]

Hi @bozana

The crossref username and password are configured:

[bozana]

Hmmm... strange...
But, I realized that my code was wrong above, it should be:

if ($crossrefPlugin === null) {
            PluginRegistry::register('generic', new \APP\plugins\generic\crossref\CrossrefPlugin(), 'plugins/generic/crossref');
            $crossrefPlugin = PluginRegistry::getPlugin('generic', 'crossrefplugin');
        }

Could you please try this code as well?
Thanks a lot!

EDIT: Ah, yes, I see, this function is called on plugin registration... so yes, it could be that CrossrefPlugin is not registered yet. Sorry :-(

[leocsilva]

Hi @bozana, no problem!
I am grateful for the help you are giving me!

Good news! After adding the code you suggested, the plugin ran perfectly and the citations were added to the crossref XML file!

[bozana]

Thanks @leocsilva. Great!
We find out a few other problems -- generally with our plugins registration, when running a job from the CLI, s. pkp/pkp-lib#11793. I will try to fix that now. Witch those changes, maybe this change here will not be needed. I will let you know, once we fixed it all.

[leocsilva]

@bozana I will be eagerly awaiting the updates to the plugin.

[bozana]

Hi @leocsilva, sorry for such a delay -- the other PR needs to be reviewed -- I think it will then also solve the issue here... I will write here as soon as the change is merged...

[bozana]

Hi @leocsilva, sorry for the delay. The new plugin release is available in the plugin gallery. I believe that this new version then does not need those changes you needed to make here. Would you be able to test/see if you can use the new version without any changes, and let me know here? You might need to clear the data cache, as admin on the Administration page, to see the new plugin version in the plugin gallery.
Thanks a lot!