Improve unit handling

[paroga]

There are some use cases, which do not work with the current system:
Example:

• supplier offers one units of 3kg cheese for 30EUR
• members order unit of 200g for 2EUR
• supplier delivers one units of 3.05kg for 30.5EUR

we can change the unit from 200g to 1g, but when receiving it we can only enter 1x3kg which is not 3,05kg (or 3050 x 1g).

I propose the following changes:

1. add an article_units field to the article model (would become 3kg in the example)
2. new field for article "package type" with the following options:

• "single article": will set unit_quantityto 1 and hide it together with article_unit (we use article_units only)

Name:  [ Tofu 250g               ]
Units: [ 1 Piece ]
Type:  [ Single Article         V]
Price: [   3 ] EUR  VAT: [ 10 ] %

• "packaged article": will show an error if unit_quantity is 1, otherwise the UI is like it is now

Name:  [ Oranges                 ]
Units: [  1 Case ]
Type:  [ Packaged Article       V]
Unit:  [    6 ] x [  1kg ]
Price: [    3 ] EUR  VAT: [ 10 ] %

• "weight article": similar to packaged article, but in the receive UI we enter the weight instead of units (e.g. [ 3050 ] x 1g)

Name:  [ Cheese                  ]
Units: [  ~ 3 kg ]
Type:  [ Weight Article         V]
Unit:  [ 3000 ] x [   1g ]
Price: [  0.1 ] EUR  VAT: [ 10 ] %

[wvengen]

This sounds really good, thanks!
An extra addition would be a per-supplier default for the article type field.
I'd love to have icons for this to show in article list views for admin views.

[mischkl]

The feature for a weight article would be very helpful and desperately needed!

We are in the process of switching to FoodSoft and are confronted with the problem that there is no way to enter sub-1kg amounts for articles that are priced by the kg.

So far we're worked around this by setting the unit to 100g, but then the price has to be divided by 10 and gets rounded up or down in comparison to the kg-price - not good! Not only does the supplier receive an order form with prices and units that are not quite correct, but people who pick up their orders can't rely on the price as listed in FoodSoft since it always has a rounding error.

[simonschmeisser]

Has this been implemented in the mean time? We are currently searching for a new software/system for Kornkammer in Freiburg but our model is based on ordering large bulk quantities (25kg) and users "buying" stock whenever they like (eg 234g). (Lager Coop)

[paroga]

Unfortunately not. Most groups just use smaller "base units" as "workaround" at the moment. That's the reason why it's so low on the priority list.