The expected behaviour is as follows:
* If the recently fetched data is older than 48 hours, it is considered
as outdated and the new fetch is executed
* else, if the recently fetched data is younger than 24 hours, it is
considered as fresh enough and no fetch is executed
* else, if the current time is after 01:00 AM plus a certain offset
(which is randomly generated for each site), the fetch is
executed.
Even in the 'Error if grade not listed case', it was applying a small
tolerance. In the case of a fuzzy match, it was returning the inexact
grade from the import file, rather than the precise grade that Moodle
was expecting.
That causes problems when the editing form is displayed, because the
value from the database does not match any of the available options, so
the grade is changed to 0%.
This fixes WCAG 2.0 compliance because we were already using HTML5 markup.
The strict XML headers setting never worked for production servers, developers
used browser validators for compliance testing. XHTML 5 option is relatively
similar to this obsolete option, but still it can not be used on production servers.
XHTML Strict 1.x was a standardised dead end, HTML5 is the new de-facto-standard
supported by all major browsers including latest versions of IE.
Please note nothing changes in our coding style because HTML5 is a superset of
several previous standards, it is recommended to use only features that are
already implemented in all our supported browsers.
For third-parth plugins, in can be helpful if the 'More help' links in
help pop-ups (the ones that come from $string['..._link'] string in the
language file) can go to other places.
This change support two other sorts of URL in addition to the standard
'course/editing' type of link that goes to MoodelDocs.
You can use absolute URLs, starting http:// or https:///
You can use a link starting %%WWWROOT%%, and that token is replaced by
$CFG->wwwroot to make the link.
1/ the sort flag can not use Intl extension constants because they may not be available
2/ add sort flag to all methods
3/ use private constructor instead of abstract - more Java like API to match the textlib
4/ add natural sorting support
5/ consistent bool return type
6/ better non-intl fallback
7/ more tests
