[FIX] pos_cache: make it compatible with onboarding tool

STEPS:
* install pos_cache in clean database without demo
* open pos
* click OK on popup "Would you like to load demo data"

closes odoo/odoo#62955

Before: error, products are not loaded even after refreshing
After: no errors, products are loaded
Signed-off-by: pimodoo <pimodoo@users.noreply.github.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/addons/pos_cache/static/src/js/pos_cache.js b/addons/pos_cache/static/src/js/pos_cache.js
index 44135607b15..9f6bf6961ea 100644
--- a/addons/pos_cache/static/src/js/pos_cache.js
+++ b/addons/pos_cache/static/src/js/pos_cache.js
@@ -21,6 +21,7 @@ models.PosModel = models.PosModel.extend({
         // uncached way, so get rid of it.
         if (product_index !== -1) {
             this.models.splice(product_index, 1);
+            this.product_model = product_model;
         }
         return posmodel_super.load_server_data.apply(this, arguments).then(function () {
           // Give both the fields and domain to pos_cache in the
@@ -28,8 +29,8 @@ models.PosModel = models.PosModel.extend({
           // values in the backend and they automatically stay in
           // sync with whatever is defined (and maybe extended by
           // other modules) in js.
-          var product_fields =  typeof product_model.fields === 'function'  ? product_model.fields(self)  : product_model.fields;
-          var product_domain =  typeof product_model.domain === 'function'  ? product_model.domain(self)  : product_model.domain;
+          var product_fields =  typeof self.product_model.fields === 'function'  ? self.product_model.fields(self)  : self.product_model.fields;
+          var product_domain =  typeof self.product_model.domain === 'function'  ? self.product_model.domain(self)  : self.product_model.domain;
             var records = rpc.query({
                     model: 'pos.config',
                     method: 'get_products_from_cache',