Hi,
So you could search and find out something about it:
https://www.mql5.com/en/search#!keyword=collect%20data&module=mql5_module_codebase

- www.mql5.com
- Intuition is wrong. To run code (EA, indicator or script,) it must be attached to a chart. But it is not limited to read only that symbol.
-
On MT4: Unless the current chart is that specific pair/ TF referenced, you must handle 4066/4073 errors
before accessing prices.
Download history in MQL4 EA - Forex Calendar - MQL4 programming forum - Page 3 #26 № 4The function linked to, opens a hidden chart for the symbol/TF in question (if not already open,) thus updating history, and temporarily placing the symbol on Market Watch (if not already there,) so SymbolInfoDouble(symbol, SYMBOL_BID) or MarketInfo(symbol, MODE_BID) don't also return zero the first call.
- Intuition is wrong. To run code (EA, indicator or script,) it must be attached to a chart. But it is not limited to read only that symbol.
-
On MT4: Unless the current chart is that specific pair/ TF referenced, you must handle 4066/4073 errors
before accessing prices.
Download history in MQL4 EA - Forex Calendar - MQL4 programming forum - Page 3 #26 № 4The function linked to, opens a hidden chart for the symbol/TF in question (if not already open,) thus updating history, and temporarily placing the symbol on Market Watch (if not already there,) so SymbolInfoDouble(symbol, SYMBOL_BID) or MarketInfo(symbol, MODE_BID) don't also return zero the first call.
👍Thanks for the details! Huge plus for hidden charts / market watch stuff.

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Hi, just want to create a script that saves quotes of a couple of pairs.
My intuition is that it should not be attached to any chart, should not be even an EA, just a simple Script.
What is the preferred way to do this in MQL4?