REST API: Cannot delete custom attribute from product

[siliconalchemy]

Cannot delete an existing product custom attribute through the rest API.

Preconditions

1. Magento CE 2.1.8
2. PHP 5.6.31

Steps to reproduce

1. Have a custom attribute with an assigned value in a product
2. PUT product update (/rest/all/V1/products/100030774) with custom attributes altered by either by assigning custom_attribute value None or removing the key/value

Expected result

1. Expect for the custom attribute to be removed/deleted from the product custom_attribute list

Actual result

1. Product doesn't remove/delete. If value is assigned None/Null, I get this error:

Updating product: 100030774: Put Error: Error occurred during "custom_attributes" processing. Value is not set for attribute code "fridge_capacity" Error updating product:  HTTPError('400 Client Error: Bad Request',)

If key/value is removed from the custom_attributes, then the Put call goes through without error, but the key/value is still present within custom_attributes, unaltered.

All other values update using exactly the same mechanism/code without issue, can add/change custom attributes correctly. Just cannot delete the custom attributes.

[orlangur]

According to https://magento.stackexchange.com/a/179153 null should do the trick. Please provide full request body.

[siliconalchemy]

It's passing this:
{"attribute_code": "fridge_capacity", "value": null}

Here's the complete json:

Updating product: 100030774: put - url: http://xxx.com/rest/all/V1/products/100030774 , data: {"product": {"sku": "100030774", "status": 1, "media_gallery_entries": [], "name": "Bosch WAN28201GB Washing Machine", "type_id": "simple", "price": 389.99, "attribute_set_id": 4, "updated_at": "2017-09-07 11:29:21", "visibility": 4, "options": [], "tier_prices": [], "custom_attributes": [{"attribute_code": "short_description", "value": "Bosch WAN28201GB 1400Rpm 8Kg A+++ With Ecosilence Drive - White"}, {"attribute_code": "manufacturer", "value": "10"}, {"attribute_code": "category_ids", "value": ["10126", "10127"]}, {"attribute_code": "options_container", "value": "container2"}, {"attribute_code": "required_options", "value": "0"}, {"attribute_code": "has_options", "value": "0"}, {"attribute_code": "url_key", "value": "bosch-wan28201gb"}, {"attribute_code": "tax_class_id", "value": "2"}, {"attribute_code": "gift_message_available", "value": "0"}, {"attribute_code": "height", "value": "848"}, {"attribute_code": "width", "value": "598"}, {"attribute_code": "depth", "value": "550"}, {"attribute_code": "model", "value": "WAN28201GB"}, {"attribute_code": "colour", "value": "145"}, {"attribute_code": "sm_featured", "value": "0"}, {"attribute_code": "group", "value": "Washing Machine"}, {"attribute_code": "build", "value": "2926"}, {"attribute_code": "warranty", "value": "2022"}, {"attribute_code": "energy_rating", "value": "2785"}, {"attribute_code": "size", "value": "2794"}, {"attribute_code": "fridge_capacity", "value": null}, {"attribute_code": "spinspeed", "value": "1400rpm Max spin speed"}, {"attribute_code": "spin_speed_rpm", "value": "1400"}], "created_at": "2017-09-07 11:29:21", "id": 82351, "product_links": [], "extension_attributes": {"stock_item": {"stock_id": 1, "qty": 27, "low_stock_date": null, "is_qty_decimal": true, "use_config_notify_stock_qty": true, "use_config_min_sale_qty": 1, "use_config_manage_stock": true, "backorders": 2, "min_sale_qty": 1, "show_default_notification_message": false, "max_sale_qty": 10000, "is_in_stock": true, "is_decimal_divided": false, "manage_stock": false, "item_id": 79318, "use_config_enable_qty_inc": true, "min_qty": 0, "qty_increments": 0, "notify_stock_qty": 1, "enable_qty_increments": false, "product_id": 82351, "stock_status_changed_auto": 0, "use_config_min_qty": true, "use_config_max_sale_qty": true, "use_config_qty_increments": true, "use_config_backorders": true}}}, "saveOptions": true}

[siliconalchemy]

That stackexchange link btw is the only one I came across with any answer, and looking at the code I think they might have been confused, the code clearly rejects null values to a key/value pair. There are lots and lots of other similar questions with no answers, however, so I suspect this is a real problem.

[davidmcnight]

I can confirm null is not working for me either. I am trying to remove an attribute. I have passed null, a blank array, an array with a value 0, an array with Null. None of them worked. When I pass null I get this: error. message
:
"Error occurred during "custom_attributes" processing. Value is not set for attribute code "conflict""

Conflict is the attribute name

The other ones get a success message but nothing is changed.

Edit: Like siliconalchemy that stackexchange is the only answer but that does not seem to be the correct answer.

[davidmcnight]

So I did something that seems to work for now -- I set the value for of 1 which is a value of another attribute and it set the attribute to null. This fixed the issue for now and I do not see any errors on the product or and the catalog/search page. I would not recommend this solution but if it is pressing this is at least a hotfix.

[cieslix]

I will take care of it

[maksek]

Hi @cieslix, can you accept invitation from github, so we can assign it on you?