How to preserve variable in indicator when switching timeframes?

//+------------------------------------------------------------------+
//|                                                     TEST IND.mq4 |
//+------------------------------------------------------------------+

#property indicator_chart_window

double var;
string comm;

//+------------------------------------------------------------------+
int init()  {
//+------------------------------------------------------------------+
  var=0;
  if (GlobalVariableCheck("G1"))
    var = GlobalVariableGet("G1");
  comm = "init " + DoubleToStr(var,5);
  Comment(comm);
  return(0);
}

//+------------------------------------------------------------------+
int deinit()  {
//+------------------------------------------------------------------+
  GlobalVariableSet("G1",var);
  if (UninitializeReason() != REASON_CHARTCHANGE)
    GlobalVariableDel("G1");
  comm = comm + "\ndeinit " + DoubleToStr(var,5);
  Comment(comm);
  return(0);
}

//+------------------------------------------------------------------+
int start()  {
//+------------------------------------------------------------------+
  var=Bid;
  comm = comm + "\nstart " + DoubleToStr(var,5);
  Comment(comm);
  return(0);
}
//+------------------------------------------------------------------+

 
int start()
  {
   int    counted_bars=IndicatorCounted();
//----
    double rsi = iRSI(NULL,0,14,PRICE_CLOSE,1);
  
    GlobalVariableSet("RSI"+Symbol()+Period(),rsi);
   
//----
   return(0);
  }

Quoting hanover

Disliked

I think I've found an answer to the first question.

To the person who messaged me, try something like this:

[code]
//+------------------------------------------------------------------+
//| TEST IND.mq4 |
//+------------------------------------------------------------------+

#property indicator_chart_window

double var;
string comm;

//+------------------------------------------------------------------+
int init() {
//+------------------------------------------------------------------+
var=0;...

Ignored

Quoting fxtr51

Disliked

Question 1:
I am using all methods which have been suggested so far.
Just to complete the solutions, there is a good one from fx1.net .
They store strings, doubles and integers in the registry.
Greatest advantage: it can be used for different applications to communicate.
The application is for free.
https://www.fx1.net/wiki/pmwiki.php/PermVar/PermVar

I used it to communicate between EAs on 2 Mt4-platforms .

Ignored

Quote

Disliked

Windows' disk cache (which is by default activated for all non-removable media) will cache the write and make it at the same time available for all read operations which will then be served directly from the cache. The written data should be available immediately after flush().
flush() will write to the cache, not the disk, so it is fast.

Quoting hanover

Disliked

I think I've found an answer to the first question.
To the person who messaged me, try something like this:

Ignored

Quoting svengralla

Disliked

The indicator is to be used in multiple instances on different charts at the same time (one instance per chart).
Changes in one instance should not affect others. Communication between instances is not necessary.

Ignored

Quoting hayseed

Disliked

//---

hey svengralla..... from hanovers words in blue above i took it that you wanted to preserve a value via globals if you physically changed the charts timeframe.....

your post here seems to imply something totaly different... so my suggestion as to how is probably is off.....h

Ignored

Quoting hayseed

Disliked

from hanovers words in blue above i took it that you wanted to preserve a value via globals if you physically changed the charts timeframe.....

Ignored

Quoting hanover

Disliked

I assumed exactly the same as you did. The words in blue were copied verbatim from Sven's PM.

Anyway, many thanks @everybody for your replies. Sounds like Sven has got it working now.

Ignored

Quoting svengralla

Disliked

Hi Hayseed,

yes, I want to preserve the value of a integer variable when physically switching the timeframe.
Besides, the indicator runs in several active charts at the same time. But this turned out to be no issue.

Hanovers code does the job and somehow it's the textbook solution, I guess.
To be honest, I didn't try out yours, since I did not fully understand what it's doing.


Best, Sven

Ignored

Quoting fxtr51

Disliked

So, if "G1" is unique for each pair and/or timeframe, nubcake and hayseed suggested solutions
to make the GlobalVariable unique and then nothing can go wrong.

Ignored

Quote

Disliked

What if the value of "G1" was written from a GBPUSD-chart before and is completely wrong for EURUSD ?
Then you have a wrong flag in your EURUSD-chart which could mess up things.

Quoting svengralla

Disliked

Thats exactly what I have been afraid of. My indicator runs simultanously in six charts with different symbols.
In each of them the global is named "G1". Still, I cant see interference of the different instances.
So, the solution works practically, though it should fail theoretically?!
Anyway, I won't touch it, unless I see the wrong behaviour.

Ignored

Quoting svengralla

Disliked

nubcake is cool

Ignored

Quote

Disliked

Thats exactly what I have been afraid of. My indicator runs simultanously in six charts with different symbols.
In each of them the global is named "G1". Still, I cant see interference of the different instances.
So, the solution works practically, though it should fail theoretically?!
Anyway, I won't touch it, unless I see the wrong behaviour.