Commodities only forward pairs are shown

[corani]

I only have currencies as commodities, and found that the inverse rates weren't shown under commodities due to:

https://github.com/aumayr/fava/blob/master/fava/api/__init__.py#L478

While this would make sense for stocks, for currencies you usually want to see the inverse as well.

[corani]

As a solution, I have a meta-tag asset-class: "Cash" on all my currency commodities, maybe this could be used to determine for which commodities the inverse should be shown?

[yagebu]

If we add something to distinguish between currencies and other commodities, it would be nice if it worked automatically without having to add any metadata. I don't put any commodity directives for currencies anyway.

How about using the following heuristic: If the commodity name has three letters or less (as all the ISO 4217 currency codes do), treat it like a curreny.

[corani]

It's not ideal, since there certainly are three or less letter stocks, but it would work for me.

Some other ideas:

• only do this for operating_currency
• use a (hardcoded) list of currency codes
• configuration option

[aumayr]

How about using the following heuristic: If the commodity name has three letters or less (as all the ISO 4217 currency codes do), treat it like a currency.

This calls for a default of "disabled" and a configuration option to enable it, because it would confuse users if they do not know about this convention. So my vote is for "configuration over convention" ;-)

[yagebu]

I guess the heuristic I suggested is actually not a good idea. If possible, I would refrain from adding another option and the following seems to be the best suggestion:

• only do this for operating_currency

[aumayr]

@yagebu Is the formatting of the numbers in the following screenshot accidental? (CHF/EUR is the calculated one)

[yagebu]

@aumayr: turns out that format_currency wasn't used. It is now.