[Notice] Undefined property: OrderDiscountModifier::$Amount when adding to cart

[adrian-stein]

I am using "silvershop/core": "1.3.0" and "silvershop/discounts": "1.2.0", old I know but it works for my client.

I just upgraded the server from PHP 7.0 to 7.1 and now it shows this error when I try and add a product to the cart. See the full error below. Any ideas what might be gong on. If i switch back to 7.0 the site runs fine.

[Notice] Undefined property: OrderDiscountModifier::$Amount
GET /products/locks-and-latches/over-centre-catches/adjustable-stainless-steel/ojop-701s-ass-ss-over-centre-catch-non-locking/
Line 3048 in C:\Nimbler\ovesco\framework\model\DataObject.php

Source
3039 $val = get_class($this);
3040 return DBField::create_field('Varchar', $val, $fieldName);
3041
3042 } else if(array_key_exists($fieldName, self::$fixed_fields)) {
3043 return DBField::create_field(self::$fixed_fields[$fieldName], $this->$fieldName, $fieldName);
3044
3045 // General casting information for items in $db
3046 } else if($helper = $this->db($fieldName)) {
3047 $obj = SS_Object::create_from_string($helper, $fieldName);
3048 $obj->setValue($this->$fieldName, $this->record, false);
3049 return $obj;
3050
3051 // Special case for has_one relationships
3052 } else if(preg_match('/ID$/', $fieldName) && $this->hasOneComponent(substr($fieldName,0,-2))) {
3053 $val = $this->$fieldName;
3054 return DBField::create_field('ForeignKey', $val, $fieldName, $this);
Trace
DataObject->dbObject(Amount)
DataObject.php:2681
DataObject->setField(Amount,0)
OrderDiscountModifier.php:50
OrderDiscountModifier->getDiscount()
OrderDiscountModifier.php:82
OrderDiscountModifier->getAmount()
ViewableData.php:120
ViewableData->__get(Amount)
DataObject.php:3048
DataObject->dbObject(Amount)
DataObject.php:2681
DataObject->setField(Amount,0)
OrderDiscountModifier.php:50
OrderDiscountModifier->getDiscount()
OrderDiscountModifier.php:27
OrderDiscountModifier->value(30)
OrderModifier.php:77
OrderModifier->modify(30)
OrderTotalCalculator.php:33
OrderTotalCalculator->calculate()

[wilr]

Can you try 1.3 of Discounts?

[adrian-stein]

I just tried that and it gives the same error.

[adrian-stein]

@wilr any other advise or help?

[wilr]

@adrian-stein What is line 50 of your OrderDiscountModifier?

The setField function might be wrong so you could try changing to $this->dbObject('Amount')->setValue($value) rather than $this->setField('Amount', $value);

[adrian-stein]

https://github.com/silvershop/silvershop-discounts/blob/1/code/modifiers/OrderDiscountModifier.php#L45 is the line causing issues.

It is really line 45 that is causing issues. I had some debug lines in the code to see if I could see what was happening which changed the error line.

so $this->setField('Amount', $amount); inside of getDiscount()

I changed it to $this->dbObject('Amount')->setValue($amount); and it still does the same thing.

[wilr]

Amount should be a database field (https://github.com/silvershop/silvershop-core/blob/1/code/model/OrderModifier.php#L14) but it looks like it is missing from the database. Perhaps put in some breakpoints like you have around line 45 and investigate $this->record to see why $Amount is missing or $this->hasField('Amount') is failing.

[adrian-stein]

Yes Amount is a database field. and shows up as a field when I do $this->hasField('Amount') or even $this->hasDatabaseField('Amount'). I can also see it in phpMyAdmin as a field on the OrderModifier table. Doing $this->record also shows the record and shows as having Amount.

Could it have something to do with the fact that OrderModifier has a function named 'Amount' and for some reason it is getting confused between that and the DB value, despite the fact that the function just calls $this->Amount?

Doing $this->dbObject('Amount) gives the error but if I try another field such as Type $this->dbObject('Type) it does not produce the error and returns back the object.

I even tried adding a new field named AmountTest and tried doing ->dbObject on that and it returned back a valid response. Its really strange.

[adrian-stein]

@wilr any more bright ideas? Is this issue just or me or do others have issues with this module and PHP 7.1?

[wilr]

I've setup a test project on PHP 7.1.23 using the below.

"silvershop/core": "^1.3",
"silvershop/discounts": "^1.2",

And I can add a product fine to the cart. Perhaps could you provide more detail on your discount that you have setup? Any other extensions or custom code?

[wilr]

@adrian-stein Try the following patch in the discounts module.

diff --git a/code/modifiers/OrderDiscountModifier.php b/code/modifiers/OrderDiscountModifier.php
index 24dd2bb..8811998 100644
--- a/code/modifiers/OrderDiscountModifier.php
+++ b/code/modifiers/OrderDiscountModifier.php
@@ -42,7 +42,7 @@ class OrderDiscountModifier extends OrderModifier {
         $calculator = new Shop\Discount\Calculator($order, $context);
         $amount = $calculator->calculate();

-        $this->setField('Amount', $amount);
+        $this->dbObject('Amount')->setValue($amount);

         return $amount;
     }
@@ -73,10 +73,6 @@ class OrderDiscountModifier extends OrderModifier {
         );
     }

-    public function getAmount() {
-        return $this->getDiscount();
-    }
-
     public function ShowInTable() {
         return $this->Amount() > 0;
     }

[adrian-stein]

@wilr If I remove the getAmount() function I can add stuff to the cart. I am not sure if all discounts and what not work correctly with that removed though.

If I just replace $this->setField('Amount', $amount); with $this->dbObject('Amount')->setValue($amount); it still doesnt work.

In terms of other shop modules I use the following

    "silvershop/core": "1.3.0",
    "silverstripe/silverstripe-omnipay": "2.0-alpha as 1.1",
    "silvershop/shipping": "0.3.0",
    "silvershop/discounts": "1.3.0",

    "burnbright/silverstripe-shop-comparison": "1.0.0",

    "markguinn/silverstripe-shop-search": "1.2.x-dev",
    "markguinn/silverstripe-shop-extendedpricing": "1.1.1",
    "markguinn/silverstripe-shop-extendedimages": "1.0.x-dev",
    "markguinn/silverstripe-ajax": "1.0.0",
    "markguinn/silverstripe-shop-ajax": "dev-master",

    "milkyway-multimedia/ss-shop-recommended": "dev-master"

I have 4 discounts in the database but none are active. Does having none active discounts affect it, or do they not do anything if they are set like that.

[wilr]

I tested it with the getAmount removed and it seemed to calculate the amount fine. Will submit a PR and see what tests fail tonight but I think that's your way to go 👍

[adrian-stein]

Awesome. Thank you very much.