app/views/multi_transfers/steps/_select_source.html.erb
<div class="alert alert-info" role="alert">
<%= t('multi_transfers.step.set_source.description') %>
</div>
<div class="form-group">
<%= select_tag('from[]',
options_for_select(
TransferSourcesOptions.new(@accounts).to_a,
selected: @from,
), id: 'select2-multi-from', multiple: @type_of_transfer == :many_to_one, required: true)
%>
</div>
<script type="text/javascript">
(function () {
var options = <%= ({
disabledOptions: @to,
value: @from
}).to_json.html_safe %>;
initializeSelect2(
"#select2-multi-from",
options
);
})()
</script>