This is a fork from [select2][https://github.com/select2/select2], just extend a function, the select all. Here is [GITHUB][https://github.com/select2/select2] Here is [documentation][https://select2.org/]
- Change tag, delete string
selectall
- Fix not working when multiple select have a same ID.
- Add select all for multiple select
- Add option
selectAllOption: true,
// select all button by default. This option is true by default, if it's multiple, then will display a checkbox select all, if set up false, then disable that. - Add option
selectAllText: 'Select all',
// Select all text This option isSelect all
by default, that is the checkbox will be show what.