moodle | Online Assignment submission Project | Math library

Try to remove your GROUP BY u.username. I don't understand well how it behaves with moodle, but there is no room for it in a SQL query like yours.

Go to the file moodle/admin/search.php

Then find and comment the line echo $adminrenderer->warn_if_not_registered();, the line number should be 56.

The end result should look like this.

When compiling the exercise to PDF, the TikZ code is rendered by pdfLaTeX, just like the rest of the exercise text. This part works for you.

However, when compiling the exercise to XML for Moodle, the TikZ code is first rendered to PDF by pdfLaTeX (like above) and subsequently converted to PNG using the R package magick. Then the Markdown text is converted to HTML and the PNG graphic embedded in the HTML. Apparently all but one of these steps work for you. The conversion of the PDF graphic to PNG fails because you don't have magick installed.

In case you have problems with the installation of magick, see the introductory vignette for more details.

ROW_NUMBER is a reserved keyword in MySQL 8.0. See https://dev.mysql.com/doc/refman/8.0/en/keywords.html

If you need to use this as an identifier, enclose it in back-ticks each time you use it.

In general it is hard to catch such problems outside of the Rmd exercise files. Instead it would be better to write the R code in the exercise in such a way that it assures that the question list only contains unique items - and if that is not the case to keep on re-sampling the parameters until there is a version that works.

Part of the problem to catch the problem in general is also that it might depend on the random number generator and its seed because the problem might just occur very rarely.

In your special case, this is a bit different because you make a full grid of all possible combinations so that each exercise file does not have any random elements anymore. Here the best solution is to run an exams2xyz() interface (or the underlying xexams() function) once, inspect the output, eliminate the problematic exercise, and then run the desired exams2xyz() interface again.

Relying on your myquestions vector with four static variants of the dynamic question01.Rmd exercise template you could do:

Problem: You have an exercise with formatting in Markdown and use xtable() to insert a table in LaTeX. This mixture of Markdown+LaTeX is no problem when converting the exercise to PDF. Internally, this preserves the LaTeX table and just converts the Markdown parts to LaTeX as well before rendering the LaTeX to PDF. However, the same is not possible automatically when converting the Markdown exercise to HTML for Moodle. The converter then does not separate the LaTeX part automatically to convert it to HTML.

In short: The different markups must be sufficiently in sync. Markdown+LaTeX markup for PDF output works and Markdown+HTML for HTML output works. But what would be even better is to have the markup fully in sync, i.e., LaTeX+LaTeX or Markdown+Markdown. Such exercises can then be rendered to either PDF or HTML automatically.

Possible solutions:

1. Markdown+Markdown: Markdown table markup in R/Markdown (Rmd) exercise
   I would recommend that you simply produce tables in Markdown via knitr::kable() rather than xtable::xtable(). Thus, the code chunk for the table simply becomes

This is a good question. Indeed exams2moodle() should be improved to throw a warning in case of such an eval specification. (Incidentally we just discussed this among the authors earlier this week.)

To the best of my knowledge it is not possible to assign negative points to num or string elements within cloze exercises. If you look at the official documentation at https://docs.moodle.org/310/en/Embedded_Answers_(Cloze)_question_type#Syntax_for_numerical_Cloze_questions you see that it is discussed how to provide a feedback text in case of a wrong answer. But this is always associated with 0%. If you just enter something like -25% in the corresponding embedded answer, this can be imported into Moodle but is actually ignored.

The only parameter that might be useful is the penalty argument - but I'm not sure how this works in Moodle. It is easy to specify in exams2moodle() and in the Moodle XML code but I couldn't find examples for the effects this has in a Moodle quiz.

As mentioned in the comments, you are returning coursesList before the asynchronous code can complete. The method executes practically instantaneously, and doesn't wait around for the async block to complete. So instead of returning the courses from the function, you can provide a completion block and pass back the response from there.

Here is a rough implementation. It may not compile so you may need to make some tweaks, especially with the error handling. I've also gone ahead and incorporated the very handy Result type, which consolidates the success and failure cases into one value. You can read more about this here, for example.

I solved the issue by editing the following file: ./htdocs/lib/dml/mysqli_native_moodle_database.php I changed this line :