Utils for internal plugin (#4483)

* Add full_code property to OrderPosition

* Add inline "json_script" as supported data source for select2

* Use shorter OrderPosition.code

src/pretix/base/models/orders.py

@@ -2835,6 +2835,14 @@ class OrderPosition(AbstractPosition):
             (self.order.event.settings.change_allow_user_addons and ItemAddOn.objects.filter(base_item_id__in=[op.item_id for op in positions]).exists())
         )
 
+    @property
+    def code(self):
+        """
+        A ticket code which is unique among all events of a single organizer,
+        built by the order code and the position number.
+        """
+        return '{order_code}-{position}'.format(order_code=self.order.code, position=self.positionid)
+
 
 class Transaction(models.Model):
     """

src/pretix/static/pretixcontrol/js/ui/main.js

@@ -552,6 +552,16 @@ var form_handlers = function (el) {
         language: $("body").attr("data-select2-locale"),
     });
 
+    el.find('[data-model-select2=json_script]').each(function() {
+        const selectedValue = this.value;
+        this.replaceChildren();
+        $(this).select2({
+            theme: "bootstrap",
+            language: $("body").attr("data-select2-locale"),
+            data: JSON.parse($(this.getAttribute('data-select2-src')).text()),
+        }).val(selectedValue).trigger('change');
+    });
+
     el.find('input[data-typeahead-url]').each(function () {
         var $inp = $(this);
         if ($inp.data("ttTypeahead") || $inp.hasClass("tt-hint")) {