Issue #190: Fix long links displaying correctly in invite.ics

[djarran]

Description: The issue described in #190 has been resolved by switching to a combination of rtrim and chunk_split.

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Problem

When we create the .ics file, we need to conform to the RFC (outlined here).

To do this, we use the wordwrap function. This function wraps at word boundaries (in this case, since we set the argument $cut_long_words to true , it only does this for words less than the limit) and removes any trailing and/or leading whitespace. For example:

//                            ⌄ 20 characters reached here
$string = 'verylongwording ashorter word here';
echo wordwrap($damn, 20, "\n", true);

//Output:
//verylongwording
//ashorter word here

Note

See that the wordwrap function doesn't wrap at exactly 20 characters, and that trailing/leading spaces at the boundary are removed.

This is problematic when we view this text in a calendar client.

This causes issues when we render this text. Even though the RFC requires each line in the description to be no more than 75 octets/characters, the container holding such text is not limited by this - i.e it is responsive. In Google Calendar, the container is ~500 pixels, displaying ~55 characters.

This meant that the above output when rendered could look like so:

//verylongwordingashorter word here

This is the same problem as described in Issue #183. That was resolved in #184 by adding a space prior to the new line. But this breaks long links/words, for example:

Prior to PR #184: https://giithub.com/catalyst/moodle-mod_facetoface/pull/191
After PR #184: https://giithub.com/cat alyst/moodle-mod_facet oface/pull/191

Solution

Use a combination of rtrim and chunk_split instead of wordwrap. This is adapted from this Stackoverflow answer about the same issue.

The chunk_split function wraps at the exact length specified and keeps whitespace.

This still follows the RFC outlined here.

Testing Instructions

1. Add plugin to a Moodle 4.3 site
2. Create XS test course
3. Add activity module
4. In the form, add a title and click 'Save and display'
5. Click 'Add a new session'
6. Set 'Session date/time known' to Yes, add a start and finish time in the current week
7. Add the following to the details section

Moodle is a free, online Learning Management system enabling educators to create their own private website filled with dynamic courses that extend learning, any time, anywhere. Whether you're a teacher, student or administrator, Moodle can meet your needs.

https://github.com/moodle/moodle/blob/321e04d630324c44929c931acfcce344b06e4a98/tag/classes/reportbuilder/local/entities/tag.php

8. Save changes
9. Sign up for session (no need to change notification type)
10. Check Mailhog, find first email
    
11. Go to MIME tab and download invite.ics file
    
12. Import into email client
13. Note that email is broken
    
14. Checkout working branch

git checkout origin/190-MOODLE_403_STABLE-ics-output 

15. Cancel booking
16. Repeat steps 9 - 12
17. Description should be formatted correctly
    

[gbarat87]

Hi @djarran
Thank you.
I have tested on my side and it works as expected.

Regards,
Guillaume