Select2 offers limited backwards compatibility with the previously 3.5.x release line, allowing people more efficiently transfer across releases and get the latest features. For many of the larger changes, such as the change in how custom data adapters work, compatibility modules were created that will be used to assist in the upgrade process. It is not recommended to rely on these compatibility modules, as they will not always exist, but they make upgrading easier for major changes.
The compatibility modules are only included in the
full builds of
Select2. These files end in .full.js, and the
compatibility modules are prefixed with select2/compat.
Added in Select2 4.0.0. This method was added to make upgrading easier from earlier versions of Select2.
During the Select2 4.0.0 release, the
matcher function was changed to allow for more complex
matching of nested objects.
matcher
term and the data object
text.
oldMatcher
The custom matcher example provides a
guide for how to use this in your own application. For those upgrading
from older versions of Select2, you just need to wrap your old
matcher with this function to maintain compatibility.
initSelection
Deprecated in Select2 4.0. This has been replaced by another option and is only available in the full builds of Select2.
In the past, Select2 required an option called initSelection
that was defined whenever a custom data source was being used, allowing
for the initial selection for the component to be determined. This has
been replaced by the current method on the
data adapter.
initSelection
callback
DataAdapter
InitSelection
query
Deprecated in Select2 4.0. This has been replaced by another option and is only available in the full builds of Select2.
In the past, Select2 supported an option called query that
allowed for a custom data source to be used. This option has been replaced
by the query method on the
data adapter and takes a very similar set of
parameters.
query
params (including a callback)
DataAdapter
Query
<input type="text" />
Deprecated in Select2 4.0.
It is now encouraged to use the <select> tag instead.
In past versions of Select2, a <select> element could
only be used with a limited subset of options. An
<input type="hidden" /> was required instead, which did
not allow for a graceful fallback for users who did not have JavaScript
enabled. Select2 now supports the <select> element for
all options, so it is no longer required to use <input />
elements with Select2.
DataAdapter
InputData