Wrong Weight Total in Cart- a second cause

[cogitoergo]

Previous threads (now closed) -- https://www.zen-cart.com/showthread....hipping-weight, and tutorial -- https://www.zen-cart.com/content.php?127 suggest that the Tare Weight settings are the source of the error in the weight totals shown on the cart page. This is a common source of this error.

The symptom of precisely double the total of many of the individual items in the cart suggested to me another source:
When "Priced by Attributes" is set in the admin Product Page and the attributes have weights, the shipping weight in the input box at the bottom must be set to zero. Otherwise, the cart totals both the base weight and the attribute weight, which doubles the weight for the default product.

So, set the base product weight to zero when pricing by attributes. This has the unfortunate side effect of setting the display of the weight to zero in the store's Category Pages (because the attribute has not yet been selected until the Product Page is accessed and the attribute chosen). Therefore, it may be necessary to turn off the display of weight in the Category/Product pages in admin.

[mc12345678]

Previous threads (now closed) -- https://www.zen-cart.com/showthread....hipping-weight, and tutorial -- https://www.zen-cart.com/content.php?127 suggest that the Tare Weight settings are the source of the error in the weight totals shown on the cart page. This is a common source of this error.

The symptom of precisely double the total of many of the individual items in the cart suggested to me another source:
When "Priced by Attributes" is set in the admin Product Page and the attributes have weights, the shipping weight in the input box at the bottom must be set to zero. Otherwise, the cart totals both the base weight and the attribute weight, which doubles the weight for the default product.

So, set the base product weight to zero when pricing by attributes. This has the unfortunate side effect of setting the display of the weight to zero in the store's Category Pages (because the attribute has not yet been selected until the Product Page is accessed and the attribute chosen). Therefore, it may be necessary to turn off the display of weight in the Category/Product pages in admin.

attribute information associated with a product is always in some way additive (adding a negative, what have you) to the product... If choosing to enter the base weight of the product in the product information page, then the affect of the attribute should be the weight difference entered... If the weight entered for the base product is 0, then on a default ZC store, the weight will not be displayed on the product information page under "default" settings as the weight is zero, unless that factor has been changed to display regardless of the weight... Ideally, the weight would be determined the same way that the price is when an item is priced by attributes by identifying the lowest weight associated with the available option values within each option name... But as is, either the weight of the base product or no weight is displayed on the product information page and then on the shopping cart after the option(s) have been made the actual weight of the product is displayable.

I just tested this scenario on a vanilla install and yes with configuration->product listing->Display Product Weight, the default template adds a column to show the weight and will display only the product's Weight.. This is slightly different than on the product info page where a zero weight hides the weight value.. (All tests performed on ZC 1.5.4) There are options that could be taken to address this at least from the zero weight perspective, though it does seem like a "starting at" weight may be more desirable... Ie. if priced_by_attribute and weight of the product is zero then "show some text", otherwise it may be zero... Then there is the show the lowest weight of each option name's lowest option value added together to the base product weight if the product listing weight display remains....