If you pass an array as one of the params to moodle_url params() function, the exception "Coding error detected, it must be fixed by a programmer: Url parameters values can not be arrays!" is thrown.

This relates to MDL-29161. In the comments https://tracker.moodle.org/browse/MDL-29161?focusedCommentId=148346&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-148346 skodak asks where there is a usecase for moodle_url params() function to accept arrays.

Here's what I'm trying to do.

I have a form which controls the data being output in a report in a flexible table. The table should be pageable and downloadable. For those facilities to work, I need to set the base url for the table to include the form parameters.

I'm trying $currentpage->params((array)$mform->get_data()))

However, one of my form fields is a multi select box, which becomes an array of values, so the params call fails.

In discussion with timhunt he has a similar requirement in quiz reports.

The work around is to implode the array into a text string to pass as a single param, and then ensure all code handles the param as an array or a text string. But that's rather clunky.

It would be great if moodle_url could handle this situation without workarounds.