RBoelter/citations Not work [OJS]

Hi all,

I use OJS 3.2.1-1.

I have installed plugin GitHub - RBoelter/citations at stable-3_1_2

i put that plugin in the generic folder.

I face the problem that the configuration setting is not saved (i save and open again, configuration blank)
please see this figure:

and error_log are:
[05-Dec-2020 20:48:53 Asia/Jakarta] PHP Warning: simplexml_load_string(): Entity: line 1: parser error : Start tag expected, ‘<’ not found in /home/polgnac/public_html/jurnal/plugins/generic/citations/classes/CitationsParser.inc.php on line 64
[05-Dec-2020 20:48:53 Asia/Jakarta] PHP Warning: simplexml_load_string(): not authorized to view references in /home/polgnac/public_html/jurnal/plugins/generic/citations/classes/CitationsParser.inc.php on line 64
[05-Dec-2020 20:48:53 Asia/Jakarta] PHP Warning: simplexml_load_string(): ^ in /home/polgnac/public_html/jurnal/plugins/generic/citations/classes/CitationsParser.inc.php on line 64

and plugin result:

anyone can help me?

Thank you

the API keys were saved when the input fields have a blue border (see text above these fields). I will change this in the next version to a more common way with ‘*******’.
I fixed the simplexml warnings in the last commit, and they will be gone in the next version. The plugin should work with these warnings though, as they only occur when the article has no citations.

Can you please check if your article actually has citations on Crossref and Scopus and if so, how many. Because if the plugin shows “0”, it could not find citations for this DOI via the APIs.

You are using OJS, but you wrote that you installed GitHub - RBoelter/citations at stable-3_1_2 which is the branch for OJS 3.1.2.x Please use the master branch for 3.2.x or Release for OJS-3.2.x · RBoelter/citations (github.com) or install the plugin via Plugin Gallery.


One more thing we must get permission from crossref.

I have contact them and get permission. It’s working now

Thank you


I am using OJS version, and I am checking and getting various things with the Scopus / Crossref plugin v3.1.0.2.

  • The apis keys are not saved in the plugin configuration:


  • In some articles it tries to load the plugin, and in the end it doesn’t work and I get the following error:


PHP Fatal error:  Uncaught Error: Call to undefined function is_countable() in /plugins/generic/citations/classes/CitationsParser.inc.php:174\nStack trace:\n#0

as written above, the API keys were saved if the input fields have a blue frame.
It seems that your OJS is running with a PHP Version < 7.3, because is_countable() was added in PHP 7.3. I’ll check if I can use another function to check the result arrays.


Hi @RBoelter,

Yes, my server is running the version of php 7.2. What else could you do in this case?

I will implement a workaround for PHP 7.2, but it will take a few days because I have an extremely full schedule this month. Another solution could be to upgrade your server to PHP 7.3, especially since PHP 7.2 has reached EOL (End of Life) in November 2020. PHP: Supported Versions

Dear @RBoelter,
please can you help with following php error:
[php7:error] [pid 86745] [client] PHP Fatal error: Uncaught Error: Call to undefined method Application::getHttpClient() in /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/plugins/generic/citations/classes/CitationsParser.inc.php:109\nStack trace:\n#0 /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/plugins/generic/citations/classes/CitationsParser.inc.php(13): CitationsParser->getAPIContent(‘https://api.els…’)\n#1 /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/plugins/generic/citations/classes/CitationsHandler.inc.php(34): CitationsParser->getScopusCitedBy(‘10.15414/jmbfs…’, ‘bf28f8d02d3a626…’, 1)\n#2 /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/lib/pkp/classes/core/PKPRouter.inc.php(391): CitationsHandler->get(Array, Object(Request))\n#3 /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/lib/pkp/classes/core/PKPPageRouter.inc.php(231): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)\n#4 /data/8/5/8593ba5c-3992-45ef-8e in /data/8/5/8593ba5c-3992-45ef-8e30-9829ff8933f1/jmbfs.org/sub/office2/plugins/generic/citations/classes/CitationsParser.inc.php on line 109, referer https://office2.jmbfs.org/index.php/JMBFS/article/view/3194

Hi @Lukas_Hleba,
Which plugin and OJS version do you use?
The line 109 should be Application::get()->getHttpClient(); and not Application::getHttpClient() if you are using OJS 3.3.0-X.

Hello @RBoelter,
i am using OJS and plugin release
Thank you for quick response

Ok, it seems that you haven’t installed the plugin via the OJS plugin gallery, because the plugin version for OJS is citations-v3_2_0-3.tar.gz. You can find the correct release for OJS 3.2 here: Releases · RBoelter/citations (github.com), or install it via the plugin gallery.