Allow image size to be changed

[gordonwatts]

There are times that images on disk aren't the proper size (too big?) to be displayed in the exam. The Canvas quiz-question editor allows one to change the image size by hand. Short of using a full <img ... .> tag in your markdown there isn't a way to do that inline in hte markdown.

[gordonwatts]

One possible solution is to use the markdown extension called attr_list, which allows you to set attributes for a html element created in markdown. This is part of the markdown processor that text2qti is already using; it is just a matter of turning it on.

This commit to my fork of text2qti does that.

If you are interested in this as a solution to this problem (or any other generic one that attributes might solve), I'm happy to submit a PR.

[gpoore]

Support for attributes in general is a good suggestion. I think I looked at the attr_list extension once, but didn't turn it on because I'm trying to keep everything as compatible as possible with Pandoc Markdown. I just took a quick look at the attr_list extension source (https://github.com/Python-Markdown/markdown/blob/master/markdown/extensions/attr_list.py). It would probably be easy to create a custom version that is more or less compatible with Pandoc. Basically, swap opening delimiter from {: to { and then limit what can have attributes. I suppose it would also be possible to add an option to enable the existing attr_list as-is.

[gordonwatts]

Ok - finished finals for this quarter.

If it is possible to change, then I'd suggest not using the { since other things are changing because that is a special character to python (in f-strings).

I'm ok with creating a new flag and turning on and off attr_list. If you are interested in that PR let me know. If you want to modify attr_list' source, that might require a little more work, and perhaps should be done with pandoc in mind (and I've never used pandoc).

[gpoore]

I've added support in the last commit for Pandoc-style attributes on images. This is similar to attr_list, but uses {<attrs>} instead of {:<attrs>}. Currently, attributes are only supported on images, but that can be easily extended in the future. Since the syntax is compatible with Pandoc, this feature automatically works with solutions export.

[gordonwatts]

I think this takes care of this - thanks! Feel free to close this!

[tdstoff]

Can anyone provide an example of this working with an actual image file? Specifically changing the image size. I haven't found it in the README or anywhere else.

For example, I try below to do a simple modification to an example file in a repo here. In the example, the image files are generated by matplotlib on the fly. My only addition was trying to modify the width of one of the images with {width="100px"}.

import textwrap
import matplotlib.pyplot as plt
for c in ['red', 'blue']:
    plt.plot([1,2,3,4], color=c)
    plt.ylabel('some numbers')
    plt.savefig(c+'.png')
q=rf"""
1. What is your favorite color?
[*] ![The data for the question](red.png){width="100px"}
[*] ![The data for the question](blue.png)
"""
print(textwrap.dedent(q))

Any time I add the attributes, I get various errors depending on the question type and whether the image is part of the question or answer. Here it gives:

Code execution resulted in errors:
--------------------------------------------------
  File "/var/folders/d9/n16xn0557wqbvqhcywpth__m0000gn/T/tmpm5c5ipwz/be906e50bc50f19c.code", line 9
    [*] ![The data for the question](red.png){width="100px"}
                                                    ^^^^^^^
SyntaxError: f-string: expecting '!', or ':', or '}'

--------------------------------------------------

[gpoore]

@tdstoff The admittedly very short relevant documentation is here: https://github.com/gpoore/text2qti?tab=readme-ov-file#images. The error that you provided is due to the format string. You can either switch to a regular string (remove f) or double the braces {{...}}. The width shouldn't be quoted ({width=100px}); I should add a note to the documentation that quoting isn't supported, or see if I can add quote support.

[tdstoff]

That works, thank you!