Problem getting Global Variables to Work | Forex Factory

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Problem getting Global Variables to Work

  • #1
  • First Post: Aug 10, 2011 12:05pm Aug 10, 2011 12:05pm
I am using Global variables to store data between terminal sessions.

Everything seems fine. My GV's are saved, recalled and updated exactly as I want them and I can see they are writing to the Globals file (gvariables.dat)

However, when I restart the terminal, The Globalvariable file gets truncated with the loss of the saved data.

I have confirmed that it is not my code which is doing this by ensuring my EA is not loaded on startup.


I've attached a screen dump to show what I see in explorer.

Is there a guru out there who can help me?
Attached Image (click to enlarge)
Click to Enlarge Name: gvariables.dat.gif Size: 41 KB
  • #2
  • Aug 10, 2011 12:50pm Aug 10, 2011 12:50pm
hey dc...... it should not matter whether you shutdown the platform, the computer or the ea..... the global variables should stand as last set......

or at least mine do.... i'm using ibfx's version not ava's..... wouldn't think it would matter though......

do they clear if you shut down the ea but not the platform.......h
to trade and code, keep both simple... no call to impress....h
  • #3
  • Aug 10, 2011 1:01pm Aug 10, 2011 1:01pm
Quoting hayseed
do they clear if you shut down the ea but not the platform.......h
No.The file is saved fine when the terminal is closed. The problem happens when the terminal is started. It's driving me nuts
  • #4
  • Aug 10, 2011 1:04pm Aug 10, 2011 1:04pm
Quoting hayseed

or at least mine do.... i'm using ibfx's version not ava's..... wouldn't think it would matter
I get the same behaviour on alpari.
  • #5
  • Aug 10, 2011 8:56pm Aug 10, 2011 8:56pm
DC, off the wall idea, I would look at two things. First is the variables in the proper place within the code. they have to be initialized if not then they will be erased. The other thing would be to look for a global delete somewhere, this may be within a chart indicator. You can also change the file name and see if that works. good luck
  • #6
  • Aug 10, 2011 9:13pm Aug 10, 2011 9:13pm
this is an example of how i do it...... there might be better methods.....

it's from an ea that has never failed me.... whether the chart is closed, the terminal shutdown or computer turned off accidentally or otherwise...... the globals always stay intact......h

//---
//---

Inserted Code
 
       if(SymProfit(symbol) > maxprofit[i]) {maxprofit[i] = SymProfit(symbol);} else {maxprofit[i] = maxprofit[i];}
       if(SymProfit(symbol) < maxloss[i])   {maxloss[i]   = SymProfit(symbol);} else {maxloss[i]   = maxloss[i];}
       Display("maxprofitlabel" + symbol + i,  horizontal + 900 ,vertical-30);
       ObjectSetText("maxprofitlabel" + symbol + i, "Max Profit", 12, "Verdana", Blue);
 
       Display("symmaxprofit" + symbol + i,  horizontal + 900 ,vertical +(i*26));
       ObjectSetText("symmaxprofit" + symbol + i, DoubleToStr(GlobalVariableGet(symbol+"maxprofit"),2), 12, "Verdana", Blue);
 
       Display("maxlosslabel" + symbol + i,  horizontal + 1000 ,vertical-30);
       ObjectSetText("maxlosslabel" + symbol + i, "Max Loss", 12, "Verdana", Blue);
 
       Display("symmaxloss" + symbol + i,  horizontal + 1000 ,vertical +(i*26));
       ObjectSetText("symmaxloss" + symbol + i, DoubleToStr(GlobalVariableGet(symbol+"maxloss"),2), 12, "Verdana", Blue);
 
 
       if(maxprofit[i] > GlobalVariableGet(symbol+"maxprofit")) {GlobalVariableSet(symbol+"maxprofit", maxprofit[i]);} 
       if(maxloss[i]   < GlobalVariableGet(symbol+"maxloss"))   {GlobalVariableSet(symbol+"maxloss", maxloss[i]);} 
       }   
 
       if(AccountMargin() > GlobalVariableGet("maxmargin"))     {GlobalVariableSet("maxmargin", AccountMargin());} 
       if(AccountMargin() < GlobalVariableGet("minmargin"))     {GlobalVariableSet("minmargin", AccountMargin());} 
       if(AccountFreeMargin() > GlobalVariableGet("maxfreemargin"))     {GlobalVariableSet("maxfreemargin", AccountFreeMargin());} 
       if(AccountFreeMargin() < GlobalVariableGet("minfreemargin"))     {GlobalVariableSet("minfreemargin", AccountFreeMargin());} 
       if(AccountProfit() > GlobalVariableGet("maxaccprofit"))     {GlobalVariableSet("maxaccprofit", AccountProfit());} 
       if(AccountProfit() < GlobalVariableGet("minaccprofit"))     {GlobalVariableSet("minaccprofit", AccountProfit());} 
       if(AccountEquity() > GlobalVariableGet("maxaccequity"))     {GlobalVariableSet("maxaccequity", AccountEquity());} 
 
       Display("maxmarginlabel",  horizontal + 1100 ,vertical-30);
       ObjectSetText("maxmarginlabel", "Max Margin", 12, "Verdana", Blue);
 
       Display("maxmarginamount",  horizontal + 1100 ,vertical +20);
       ObjectSetText("maxmarginamount", DoubleToStr(GlobalVariableGet("maxmargin"),2), 12, "Verdana", Blue);
to trade and code, keep both simple... no call to impress....h
  • #7
  • Aug 11, 2011 2:45am Aug 11, 2011 2:45am
Quoting twj1usa
The other thing would be to look for a global delete somewhere, this may be within a chart indicator.
Thank you so much. I found the problem. There was an indicator using GlobalVariablesDeleteAll().


The strange thing was that it was using a parefix parameter which should have restricted what it was deleting:

"int GlobalVariablesDeleteAll( string prefix_name=NULL)
Deletes global variables. If the name prefix is not specified, all global variables will be deleted. Otherwise, only those variables will be deleted, the names of which begin with the specified prefix. The function returns the count of deleted variables. "
  • #8
  • Aug 11, 2011 3:19am Aug 11, 2011 3:19am
sounds like it's being passed an empty string variable, therefore, does delete all globals.
Congratulations ScalaFX for coming out of the closet!
  • #9
  • Aug 11, 2011 3:28am Aug 11, 2011 3:28am
Quoting nubcake
sounds like it's being passed an empty string variable, therefore, does delete all globals.
That would make sense.

This is the offending line in the indicator which is on 26 charts

GlobalVariablesDeleteAll(UniqueID + Symbol());

It's part of init().

UniqueID is an extern

In my EA, I am using an entirely different prefix
  • #10
  • Aug 11, 2011 3:57am Aug 11, 2011 3:57am
Quoting dietcoke
That would make sense.

This is the offending line in the indicator which is on 26 charts

GlobalVariablesDeleteAll(UniqueID + Symbol());

It's part of init().

UniqueID is an extern

In my EA, I am using an entirely different prefix
even if UniqueID is blank symbol should still return a value though, and so it should resolve to SOMETHING at least and not a blank value being passed to the global delete.

just for the sake of finding out what the deal is it might be worth dumping uniqueid + symbol() into a separate string variable and then printing this variable to the journal or screen to see what it is resolving to. it might reveal some unexpected oddity of mt4... something like, perhaps symbol() doesn't hold a value yet when inside the init function even though it should.
Congratulations ScalaFX for coming out of the closet!
  • #11
  • Aug 11, 2011 4:53am Aug 11, 2011 4:53am
Quoting nubcake
even if UniqueID is blank symbol should still return a value though, and so it should resolve to SOMETHING at least and not a blank value being passed to the global delete.
Thats what I thought.


Quoting nubcake
just for the sake of finding out what the deal is it might be worth dumping uniqueid + symbol() into a separate string variable and then printing this variable to the journal or screen to see what it is resolving to. it might reveal some unexpected oddity of mt4... something like, perhaps symbol() doesn't hold a value yet when inside the init function even though it should.
I've now tried:

commenting the prefix to the screen which it does fine both as the concatenated string and as a variable
using that variable as the parameter to GlobalVariableDeleteAll.

This is very strange.

Anyway as it happens I'm not currently using the Indicator feature which uses GV's so I've commented out the code.

Thanks to everyone who helped.

I wonder if I can bill my wasted day to metaquotes?
  • #12
  • Aug 11, 2011 5:19am Aug 11, 2011 5:19am
maybe you are running an old build of mt4?

this from 2006 has the same issue http://www.metatrader4.com/forum/2500

i don't want to risk losing all of the globals that i use with my own stuff, so i'm not going to test if it works properly or not on the latest mt4 build.

either way, it's easy enough to iterate through the globals (remembering to go from last to first) using globalvariablestotal and globalvariablename, do a stringfind, and checking the returned value to decide if a global should be deleted or not.

this IS what the deleteall function should be doing when a string is specified, so it's either broken (typical mt4) or something hokey is going on and you need do the extra 4 or so lines of code yourself and know that it will simply work as you want it to.
Congratulations ScalaFX for coming out of the closet!
  • #13
  • Last Post: Aug 11, 2011 5:59am Aug 11, 2011 5:59am
Quoting nubcake
maybe you are running an old build of mt4?

this from 2006 has the same issue http://www.metatrader4.com/forum/2500

i don't want to risk losing all of the globals that i use with my own stuff, so i'm not going to test if it works properly or not on the latest mt4 build.

either way, it's easy enough to iterate through the globals (remembering to go from last to first) using globalvariablestotal and globalvariablename, do a stringfind, and checking the returned value to decide if a global should be deleted or not.

this IS what...

That was well dug up

I'm running build 402. It looks like they didn't fix it.
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