Require decimal point when user enters currency amount

e.g. '10.' or '.10' is ok, but '10' is not allowed due to ambiguity

wuttapos/views/pos.py

@@ -1042,6 +1042,19 @@ class POSView(WuttaView):
         self.show_snackbar(text, bgcolor='yellow')
         self.page.update()
 
+    def require_decimal(self, value):
+        try:
+            amount = decimal.Decimal(value)
+        except decimal.InvalidOperation:
+            self.show_snackbar(f"Amount is not valid: {value}", bgcolor='yellow')
+            return False
+
+        if '.' not in value:
+            self.show_snackbar(f"Decimal point required: {value}", bgcolor='yellow')
+            return False
+
+        return amount
+
     def open_ring_click(self, e):
         value = self.main_input.value or None
         if not value:
@@ -1049,10 +1062,8 @@ class POSView(WuttaView):
             self.reset()
             return
 
-        try:
+        amount = self.require_decimal(value)
-            amount = decimal.Decimal(value)
+        if amount is False:
-        except decimal.InvalidOperation:
-            self.show_snackbar("Amount is not valid")
             self.reset()
             return
 
@@ -1131,16 +1142,14 @@ class POSView(WuttaView):
             self.page.update()
 
         def confirm(e):
-            dlg.open = False
+            price = self.require_decimal(price_override.value)
-
+            if price is False:
-            try:
-                price = decimal.Decimal(price_override.value)
-            except decimal.InvalidOperation:
-                self.show_snackbar(f"Price is not valid: {price_override.value}", bgcolor='yellow')
                 self.main_input.focus()
                 self.page.update()
                 return
 
+            dlg.open = False
+
             session = self.app.make_session()
             user = self.get_current_user(session)
             handler = self.get_batch_handler()
@@ -1507,12 +1516,9 @@ class POSView(WuttaView):
             return
 
         # nothing to do if amount not valid
-        try:
+        amount = self.require_decimal(self.main_input.value)
-            amount = decimal.Decimal(self.main_input.value)
+        if amount is False:
-        except:
             session.close()
-            self.show_snackbar(f"AMOUNT NOT VALID: {self.main_input.value}",
-                               bgcolor='yellow')
             self.reset()
             return