is there any reference on how the function AVAIL exactly works and how many parameters it accepts?
Does the function behave the same way when the returned value is NULL, "NaN" or "Unable to collect data" ?
In the specific, I'm trying to recover information which is stored in different fields according to the asset class. For example, TR.PriceClose for ordinary shares but TR.FundNAV for funds.
Is there a IF/CASE function like this?
IF(Assetclass = Fund; TR.FundNAV; TR.PriceClose)
If you follow Formula Builder wizard in Eikon Excel, at the bottom of Parameters & Quick Functions tab you can find the link to the Expression Editor (see the screenshot).
By following this link and expanding More Options you can find the descriptions of the functions you can use in an expression. The description of Available function reads "Available is used to find the first data item in your request that is a valid value. The system will run the first data item and if its null it will move on to the next data item until a value is returned or it reaches the last item and a null or value is returned. This is done per data point if running a time series request".
Based on this description you can indeed use Available function for the purpose you described, e.g.