Historical Bid/Ask Info

[davewolfs]

Just a question about the API, since it is not possible to obtain historical bid ask information through EFS, is this something that would be accessible using the Desktop API? If so, what functions would I require in order to do so. And finally, would it be possible to integrate a DLL that uses the Desktop API with my EFS code?

I appreciate any answers.

Thank you,

Dave

[davewolfs]

Re: Historical Bid/Ask Info

Originally posted by davewolfs
Just a question about the API, since it is not possible to obtain historical bid ask information through EFS, is this something that would be accessible using the Desktop API? If so, what functions would I require in order to do so. And finally, would it be possible to integrate a DLL that uses the Desktop API with my EFS code?

I appreciate any answers.

Thank you,

Dave

Is support familiar with EFS DLL capabilities? The claim is that data cannot come from anywhere else.

I don't see how this is possible based on this info.

http://kb.esignalcentral.com/display/2/articleDirect/index.asp?aid=1190&r=0.4302942

DLLs



EFS has the ability to call functions distributed in DLL (Dynamic Link Library) files.



Working with DLLs

A dynamically linked library (DLL) is a collection of software functions (mini-programs) that can be called by applications or other DLLs. A DLL is what lets many applications share one copy of a routine they all have in common. It can be said that Microsoft� Windows� is simply a collection of DLLs.



Sample.efs File That Calls DLL Object



var d = new DLL("d:/testdll/debug/testdll.dll");

d.addFunction("test", DLL.DOUBLE, DLL.CDECL, "Testing123", DLL.INT, DLL.STRING, DLL.FLOAT, DLL.DOUBLE, DLL.BYTE);



function preMain() {

var v = d.call("test", 123, "testing 123", 456, 544, 65);

debugPrint("v = " + v + "\n");

}



function main() {



}



DLL Object in EFS



The DLL object allows you to write formulas that can communicate with a DLL.



Step 1: Create a DLL object.



Syntax:

Var d = new DLL("DllPath");



Sample:

Var d = new DLL("c:/testdll/testdll.dll");



Step 2: Add Functions to be accessed. A DLL may have one more exported functions. Use the addFunction member to access your exported functions.



Syntax:

AddFunction("refname", ReturnType, FunctionDefType, FunctionName, [Parameters�]);



ReturnType is one of:

DLL.DOUBLE

DLL.INT

DLL.SHORT

DLL.FLOAT



FunctionDefType is one of:

DLL.CDECL

DLL.STDCALL



If your C/C++ function uses the __cdecl keyword, use DLL.CDECL

If your C/C++ function uses the __stdcall keyword, use DLL.STDCALL



FunctionName is the name of the C/C++ function being called. Note: Your compiler may mangle the function name. You will need to reference the MAP file generated by the linker to determine the actual name. In some cases the compiler prepends the function name with an underscore "_". In other cases the compiler mangles the function name.



Parameters

DLL.BYTE

DLL.STRING

DLL.SHORT

DLL.INT

DLL.FLOAT

DLL.DOUBLE

DLL.VOID

DLL.FLOATARRAY (float *)

DLL.DOUBLEARRAY (double *)



Sample. The "addFunction" calls corresponds with the following C/C++ function.



d.addFunction("MyCallName", DLL.DOUBLE, DLL.CDECL, "Testing123", DLL.INT, DLL.STRING, DLL.FLOAT, DLL.DOUBLE, DLL.BYTE);



double __declspec(dllexport) __cdecl Testing123(int i1, PCSTR p1, float f1, double d1, BYTE b1) {

}



Note: All functions associated with a DLL object will share an instance. If you want each function to share a separate instance, instantiate multiple DLL objects.



Step 3: Call the Function



Syntax:

d.call("refname", [Parameters]);



Sample: This will call the Testing123 function per Step 2.



d.call("MyCallName", 123, "testing 123", 456, 544, 65);

[eSignal_AveryH]

Dave,
Let me ask this question to our EFS Developer Gurus and once I have an answer I'll post back.

While I'm asking can I get a little more information;

Is your plan to add the historical data back into the charts?

Can you give me an idea of what type of calculation or analyics you're creating?