Obtaining valid symbols from broker in MT4

Hello All,

I'm turning once again to the friendly folk and FF for some guidance on MT4 programming. I've searched the documentation but am yet to find out if I can do what I'd like to do.

I'm writing an EA that analyses data in all currencies. For this EA, the more currencies available to analyse the better. Each broker has a different range of currencies on offer, so it would be nice to make the EA automatically adjust to whatever symbols are available. At the moment my EA gets divide by zero errors, as it is trying to perform calculations for data that may not be available.

Can anyone tell me if it is possible to automatically retrieve a list of valid symbols from the broker? It is clear that the MT4 application does this in the watch window, so I expect it should be possible in an EA.

Also, is it possible to check the symbol to make sure it is usable before processing data from it? Again, I want to ensure EA robustness and remove the dreaded divide by zero error in the unlikely event that a broker withdraws a currency.

Thanks once again.

Michael

hi michael,

you can retrieve symbol list on a file named "symbols.sel" located on history folder. attached is a script that will read symbls.sel, parse all symbols found and print them on screen.

hth

Also look at .setfiles in symbolsets folder. This might require some manual maintenance.
To see if a symbol is still active, make sure you have ShowAll in MarketWatch, then use MarketInfo and get the Bid (might be zero), also get Time and compare that to your computer clock time (or a known symbol like EU) to see if it is still current. There are some arb programs around that take every possible XXX and combine it with every possible YYY and check for availability.
ps: Never ever get a divide by zero. if(y!=0) a=x/y;
ps2: sangmane: That is very fine code!

Hi there,

Thanks for the ideas, they are much appreciated. I'm surprised that metatrader doesn't offer this info from some kind of function call, I would have thought that it would be a reasonably common thing to do.

I might try looking for 0 bid levels, and if that doesn't work I'll have a go at using the parsing code. Both sound like good solutions.

Thanks once again for your help, FF is a great forum with some great members!

Cheers,

Michael.