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Moodle plugins directory: Opaque
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This question type uses web services to connect to other question engines like OpenMark or ounit, so that their questions can be used in a Moodle quiz.
2.2 For Moodle 2.3+
Moodle 2.3, 2.4
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Fri, Feb 17, 2012, 1:04 AM
on version 2.21+ this will not install. On the notifications pages it comes up with a version error, any thoughts?
Fri, Apr 27, 2012, 2:49 PM
I want to use 'Opaque Type Question'
Any Default Values/ An Example for this Question Type ?
I stuck at
Question engine ??
Question id ??
Question version ??
You may just provide link.
Mon, Apr 30, 2012, 2:55 PM
. Whatever question engine you are using should tell you what settings to put in those fields.
Tim Larcombe, this is not a good place to report bugs, as you can probably tell. In the tracker is better:
Mon, Apr 30, 2012, 8:27 PM
Thanks or response.
I already visited
But i couldn't get expected information.
1) What is Question engine URLs ( for Opaque)
2) Where do i get 'Question ID' & 'Question version' ? (For opaque)
Sat, Oct 27, 2012, 11:25 PM
Hi, there. I installed Stack server and Moodle 2.3 I followed all instructions from the following URL
However, when I wanted to intall opaque question plugi. appeared a window with the following message: Requires
Sun, Oct 28, 2012, 9:26 AM
It sounds like you are trying to install STACK version 2.0. There is now a STACK version 3.0, which is better integrated with Moodle, and easier to install. See
. I recommend you install that instead.
Tue, Oct 30, 2012, 12:33 AM
Hi, Tim. I appreciate your time to help me. Stack ver. 3.0 inside Moodle was installed successfully. I started to add a Stack question. Cheers
Tue, Oct 30, 2012, 2:48 AM
Hi, there. I started with a new Stack question. I followed the Stack documentation. However, when I clicked to create the question the following error message appeared in the the section Model answer
CAS failed to return any data. ans1:3*(x-1)^2
I decided to run the healthcheck.php script. This script showed all information without any error message.
Tue, Oct 30, 2012, 11:24 PM
Hi there. I found what my problem was with the following error:
CAS failed to return any data. ans1: 3*(x-1)^2
After I checked it out, it was the maxima CAS version installed on the server. I updated on the Stack configuration and it is working.
Thu, Feb 28, 2013, 4:09 AM
Hello. Opaque doesn't seem to function properly (Moodle 2.3).
When trying to create an Opaque question, while using Developer debug mode, the form does not appear, instead a Strict Standards error message appears, about a non-existent HTML element (questiontext and generalfeedback). At the upgrade.txt of question/type (
), at the = 2.3 = section it states:
" If you are overriding export_to_xml and import_from_xml to provide Moodle XML format
import and export, then you will probably get PHP strict syntax notices in developer
debug mode until you change the method signature to include qformat_xml $format.
That is, you need to specify the argument type."
After correcting the argument type at question/type/opaque/questiontype.php as above, the new opaque question form still doesn't appear. Instead, an error occurs starting with:
"QuickForm Error: nonexistent html element Element 'questiontext' does not exist in HTML_QuickForm::getElement()"
"Fatal error: Call to undefined method HTML_QuickForm_Error::getValue() in [...]moodle/question/type/edit_question_form.php on line 441 "
As a quick solution, I've tried editing edit_opaque_form.php, by commenting out this part:
That does the trick (the form appears and an Opaque question can be created) but I don't like the idea of such a solution and I think it's causing other problems to the Opaque engine communication.
Fri, Mar 1, 2013, 2:30 AM
That's odd. It works fine for us at the OU, in both 2.3.x and 2.4.x. Are you sure you have the latest version of the code.
Fri, Mar 1, 2013, 4:37 AM
My colleague installed it some days ago through git so I suppose it's the latest version. Nevertheless, I tried to reinstall it, in case it was outdated, but when trying to uninstall Opaque, there's this error:
"You cannot delete the question type 'Opaque'. There are other question types installed that rely on it."
(however, no qtypes seem to be associated)
And when trying to uninstall opaque behaviour, there's that error:
"You cannot delete the behaviour 'Question managed by a remote engine'. It is used by question attempts."
If it matters at all, Moodle version.php:
$version = 2012062504.06;
$release = '2.3.4+ (Build: 20130214)';
Sat, Feb 15, 2014, 12:10 AM
After fighting with the installation of opaque + testing it into moodle 2.5 with testopaque and openmark...
(BTW, openmark works only with tomcat6, not 7)
it keeps answering : "Unexpected question state."
So, I made another install of moodle (2.3), and know it does work fine...
Is the problem come from the test programs, or change in moodle behaviour, or opaque ?
Thanks in advance,
Sat, Feb 15, 2014, 12:20 AM
We are using the previous version of this question type with Moodle 2.5, and we are testing the latest version with 2. at the moment, and it is working for us.
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