add support for and use the allowClear option for select2 #2020

app/assets/javascripts/objects_input.js

@@ -11,13 +11,18 @@ var ObjectsInput = {
             const opts = {
                 placeholder: 'Search ...',
                 theme: "bootstrap",
-                width: '100%'
+                width: '100%',
+                allowClear: false
             };
 
             if ($j(this).data('placeholder')) {
                 opts.placeholder = $j(this).data('placeholder');
             }
 
+            if ($j(this).data('allow-clear')) {
+                opts.allowClear = $j(this).data('allow-clear');
+            }
+
             if ($j(this).data('tags-limit')) {
                 opts.maximumSelectionLength = $j(this).data('tags-limit');
             }

app/helpers/bootstrap_helper.rb

@@ -126,6 +126,7 @@ def objects_input(element_name, existing_objects = [], options = {}, value_metho
     options['data-tags-limit'] = options.delete(:limit) if options[:limit]
     options['data-allow-new-items'] = options.delete(:allow_new) if options[:allow_new]
     options['data-placeholder'] = options.delete(:placeholder) if options[:placeholder]
+    options['data-allow-clear'] = options.delete(:allow_clear) if options[:allow_clear]
     options[:include_blank] = ''
     options[:multiple] = true unless options.key?(:multiple)
     options[:name] = "#{element_name}#{options[:multiple] ? '[]': ''}" unless options.key?(:name)

app/helpers/observation_units_helper.rb

@@ -3,6 +3,7 @@ module ObservationUnitsHelper
   def observation_unit_selector(name, selected = nil, opts = {})
     opts[:data] ||= {}
     opts[:multiple] = false
+    opts[:allow_clear] = true
     grouped_options = grouped_observation_unit_options
     opts[:select_options] = grouped_options_for_select(grouped_options, selected&.id)