With the recent changes to how Select2 works internally, this really
isn't needed. This has been added to make the migration path
easier, and it just internally calls `val` on the underlying select
element. The only difference is that the `val` function will now
convert any non-string elements to strings.
The second argument (`triggerChange`) has not been migrated, as
Select2 now internally relies on the `change` event.
**Note:** As the old `initSelection` method has not been migrated,
it is not possible to set the `val` on remote data sources where
the value has not previously been selected.
`dropdownParent` controls the location of the dropdown when it is
automatically added to the DOM. By default, this is the body
element but it can be modified based on where the user needs it.
This adds a dictionary for converting diacritics to a normalized
representation. This dictionary is used in the default matcher.
The code for stripping the diacritics was pulled from the current
implementation in Select2 3.x.
Now when searching, a loading message is prepended to the top of
the results. This replaces the old spinner image and allows for it
to be translated across different languages.
The loading message can be styled differently and is passed
through the results formatters.
Now the options are mostly generated by hand before being passed
off to jQuery for templating. This fixes much of the speed issues
we had when they were entirely being generated through jQuery.
The matcher example now matches the old matcher example, and the
compatibility module has been turned into a function decorator
instead of a class decorator.
This starts work on the example, which currently uses the GitHub
API.
The `ajax.delay` option has been added that allows for debouncing
requests made within a certain number of milliseconds.
Now that `define` and `require` are never made public, we have to
build everything to support `$.fn.select2.amd` while also working
with other AMD loaders.
Tags no longer takes an array, as pre-existing tags should already
exist as options in the data adapter. A compatibility module will
later be added to convert tag data that is passed in to array data.
Tags allow for users to enter their own options, which will be
added to the beginning of the results list.
This makes quite a few changes, one of the major ones being the
removal of classes for marking options as selected or selectable,
and instead using the ARIA attributes which should already be
present.
Placeholder support has been implemented as a separate module, so
any selection container should be able to be decorated and get
instant placeholder support. It hooks into the updating method of
selections, and determines when to display the placeholder based
on the options that are being updated.
It works in the same way as the old placeholders. If no options
are selected and being displayed, like in the case of a multiple
select, then the placeholder will always be shown. If one option
is being displayed, and the id of the placeholder matches the id
of the selected element, then the placeholder will be shown. This
is similar to the functionality that was present in Select2 2.x,
where the placeholder could be passed in as an object that would
be compared to the selection.
This still requires that, for single selects, the first element
must match the placeholder id. Because the default placeholder id
is a blank string, this will maintain backwards compatibility with
past versions where the first option should be blank. This can
still be overridden to point at a different id, keeping support
for systems where the placeholder doesn't use a blank value.
**Note:** This does not hide the blank option for single selects,
but that will still be maintained for backwards compatibility
within the results module. It will not depend on a placeholder
being present, but instead will hide any options with blank text.
