[v1.5.8] [Moodle 4.4.9/4.5.6] [PHP 8.1] Console error on mobile when using pin comment mode

[danowar2k]

Moodle Version in use

• Moodle 4.4.9
• Moodle 4.5.6

** Plugin Version **

v1.5.8 (2025032500)

Describe the bug

When using a smartphone in a PDF annotator, and you are in pin mode and put a pin at a spot in the PDF, a console error appears. Sometimes the text editor for the comment appears and sometimes it doesn't. We can't yet discern when.
(It was very hard to scroll from the pin toolbar to the editor spot because there is not much space where you don't scroll the PDF or nothing at all, it seems).

The error:

Uncaught TypeError: Cannot set properties of null (setting 'placeholder')
    at openCommentTouchscreen (index.js?ver=00039:6878:38)
    at HTMLDocument.handleContentTouchend (index.js?ver=00039:5771:77)

To Reproduce
Steps to reproduce the behavior:

1. Create a pdfannotator, settings don't matter
2. Using a smartphone, open the pdfannotator
3. Activate pin mode
4. Touch a spot on the PDF to add a pin.
5. The error appears when you "touch up" (lift the finger)

Expected behavior
No console error should be shown, and the comment editor should always show.

Screenshots

Smartphone (please complete the following information):

• Device: Samsung Galaxy S21+
• OS: Android 15
• Browser: Android Chrome
• Version: 140.0.7339.51

[danowar2k]

The element with ID id_pdfannotator_content doesn't seem to exist at this point in time.
This seems to be defined in a mustache template called add_comment_editor_placeholder.mustache.
Which is only rendered in JS via index.js function loadEditor().

Which is seemingly done in handleDocumentMouseup (so when using a normal mouse and creating a new pin), but not in handleContentTouchend (which is the same but on a touch based device).

Compare handleDocumentMouseUp:

                deleteUndefinedPin();
                var fn = () => {
                    [textarea,data] = (0,_commentWrapper.openComment)(e,handleCancelClick,handleSubmitClick,handleToolbarClick,handleSubmitBlur,'pin');
                    renderPin();
                }
                _commentWrapper.loadEditor('add', 0, fn);

where you're saying "load the comment editor with the openComment callback call with these parameters".

Compared to handleContentTouchend:

                deleteUndefinedPin();
                var coordinates = {x: e.changedTouches[0].clientX, y: e.changedTouches[0].clientY};
                renderPinTouchscreen(coordinates);
                [textarea,data] = (0,_commentWrapper.openCommentTouchscreen)(e,handleCancelClick,handleSubmitClick,handleToolbarClick,handleSubmitBlur,'pin');

Where you don't preload the comment editor placeholder but instead just try to fill it with the comment.

[danowar2k]

A local fix seems to work for this "touch pin new comment bug".
I'll open a PR...

[danowar2k]

PR: #158

Just testing when a PR is linked and when not.

[danowar2k]

Fixed by #158

[Amrita1991]

Thank you for the pull request. It corrects the console error log. However, while testing I found that there are actuially some more console errors that comes up(not because of this change). Hence I have decided to correct as many of them as possible and then release a new version that will have these changes. So you need to wait till them to see your changes