Holdings: show conversion dropdown and apply conversion to query

[mkatsevVR]

For positions not held at cost, value function in beancount doesn't perform any currency conversion.
In Fava's Income and Balance views the user can select "cost/market value/converted to XXX" where the last option applies explicit conversion to the desired currency, even for positions not held at cost. In the Holdings view there is no such option and thus there is no way to show all holdings in the common currency.
For example:

plugin "beancount.plugins.implicit_prices"
plugin "beancount.plugins.auto_accounts"
option "operating_currency" "USD"

2001-02-01 * 
  Assets:EUR 100 EUR @@ 70 USD
  Assets:USD

Everything in USD:

No option to show everything in USD:

Would it be acceptable to add a currency dropdown to the Holdings page with the options being "cost currency/USD/EUR/whatever" ? Then the first option would work same as it does now, but if the user selects a specific currency, then we show market_value and price using that currency?

[yagebu]

Would it be acceptable to add a currency dropdown to the Holdings page with the options being "cost currency/USD/EUR/whatever" ? Then the first option would work same as it does now, but if the user selects a specific currency, then we show market_value and price using that currency?

The holdings page uses a Beancount query to generate the displayed tables. I don't think it's really feasible to integrate those with Fava's conversions. What I would suggest is to start from the query that is used on the holdings report (just click on the "Query" link) and adjust that to your liking.

[mkatsevVR]

The suggestion is to have a dropdown that would modify the query correspondingly (eg replace value(sum(position)) with convert(sum(position), "USD")). Is there some hidden complexity I'm missing that would make it infeasible?

[yagebu]

I don't want to add a second "conversion" dropdown that behaves differently from the conversion dropdown on other pages, so it would have to handle the non-currency conversion options (at cost,...) as well. That should be doable though. A PR for this would be welcome.