Search code examples
tradingalgorithmic-tradingmql4metatrader4forex

MQL4: How to fetch an economic calendar's event value?

How can I fetch the latest released value of an economic announcement using MQL4 to be compared with another variable called x?

I need to compare the fetched data (variable x) with the manually entered variable y value of 170000.

If x > y, a function is executed, and if x < y a different function is executed. 

extern int x = 170000;

extern int y = ...; //Fetch latest value of economic announcement 
                    //to compare to extern int x

void OnStart()
  {

  if(x>y){ 
      //Executes a function
  } 

  else 
  if (x<y){
      //Executes a different function
  }

  }

Using extern int, if I set x = 1 and x = 3 (or any other numbers) manually, the script works correctly. I'm just wondering if extern int will be a suitable method to fetch a value and turn it in to a number so that I can compare them both via x > y or x < y?

I have found a SLOC from another website where somebody wanted to import a whole economic calendar in to their algorithm (despite the fact that I only require one single, latest value) which I thought may be somewhat useful to include in this question. It imports data from a .csv file, so maybe I could attempt this method also. The SLOC: 

extern string HtmlAdress = "http://www.dailyfx.com/calendar/Dailyfx_Global_Economic_Calendar.csv";

I understand that latency will be a prominent issue with this method, but is this possible to achieve nonetheless?

Solution

  • Achievable? YES:

    How?

    1. find a stable and reliable source of the published data ( delay of publication, validity of data )

    2. check, how / if they operate some means of technical dissemination or remote-access to macro-data ( RSS-feed for data, not just the news-wire, flat / "ondulated" plain html web-table(s), statically named file updates etc. )

    3. Implement a proxy-scanner, that will implement (2) autonomously to external operations of the MetaTrader Terminal and it's internal code-execution units.

    4. Equip the (3) with an integration-ready means of protocol-agnostic, multi-platform, online communications with MT4 processes ( ZeroMQ, nanomsg, et al )

    5. Implement MT4 ExpertAdvisor code to include fast and efficient communication exchange and idle-handshaking with proxy-scanner (3).

    Tools?

    after many years doing this in large scale systems integration, the most efficient approach consists of a rapid prototyping development (2+3+4) a python-2.x is a reasonable option for doing this and ZeroMQ or nanomsg provide reasonably wide ported framework for (4+5)

    Example? YES:

    https://www.dailyfx.com/calendar/index_iframe.html?tz=2&sort=date&week=today&eur=true&usd=true&jpy=true&gbp=true&chf=true&aud=true&cad=true&nzd=true&cny=true&high=true&medium=true&low=true

    Brings an algorithmically parse-able html-table as a source of the needed value(s):

    <tr class ="e-cal-row" id ="eventrow10" onClick ="commentOnOff('...xml',10,'english')"> <td></td> <td>10:00</td> <td><div class="flag-32-eur"></div></td> <td width="100%">EUR German IFO - Expectations (AUG)</td> <td class="evImportance medium"><span></span></td> <td style="color:red" nowrap="nowrap"> <span style="color:red">100.1</span></td> <td nowrap="nowrap">102.4</td> <td style="color:red" nowrap="nowrap"> <span style="color:red">102.2</span></td> <td align="right"><div class="arrow"></div></td> </tr>

    Risky? YES:

    • more components means more places to implement error-recovery strategies

    • solution is ultimately dependent on the state of (2) ( implementing 1+1 source of updates possible )

    • finally, any tiny change in (2) renders your processing line to stop and enforces your implementation to loop back to (2) and re-starts re-engineering, re-implementation and re-testing steps again.