KeyToDataFile





http://www.QuantTools.com
CapeTools Grid Computing Tools function list

Welcome | Documentation format | QuantTools Groups | QuantTools Categories | Licence

Key TAGs | Excel Index | API Index



Serialises the data referenced by a list of Key string to a XML file.

Very useful under a Grid computing framework because via a single XML file, we can move data across a network and have the objects recreated on another machine.

Or we can simply store objects to disk outside of an Excel spreadsheet environment.

Because the serialised files are XML based, you can store these within a database for storage.

The data file can be read in via the ApplyKeyDataFile() function and thus all the object stored within the file will be recreated in memory.

An optional KeyTag may be required because if we simply stored all the original keys and later (via the ApplyKeyDataFile() function) wanted to recreate the objects that are contained within the KeyFile, some or all of these objects would clash with objects that are currently residing in memory.

This is most likely to happen if one executed KeyToDataFile() and then executed ApplyKeyDataFile() without removing the original objects from memory.

Applying a KeyTag (via the 'KeyTag' parameter) to each object's String-Key (or more rather, the object's string identifier) allows the previous scenario to occur while creating new objects.

This function allows you to a list of string keys via the 'KeyIds' parameter, all of which will have the same KeyTag applied to all the objects.

You can execute the ListKeyDataFile() function in order to view the list of keys that can be applied to memory.

Via the key extension tags you can determine which function(s) were used and are going to be used to create (recreate) the objects.



Note: Within Excel, the function is named - CT.GRID.KeyToDataFile




High level graphic of KeyToDataFile() function with parameters. Blue square node is the actual function with the parameters ordered.



Parameter Description


  1. FileName parameter

    Name of the file to be written (can include path).
  2. Path parameter

    Optional directory path. Will be pre-pended to the FileName parameter.
  3. KeyTag parameter

    Key tag to prepend all the keys.
  4. KeyIds parameter

    A list of QuantTools object keys.


Extended information

Function Syntax

VB Syntax


String CTGridTools.KeyToDataFile( _
String FileName, _
String Path, _
String KeyTag, _
Variant KeyIds)


Excel Spreadsheet Syntax


=CT.GRID.KeyToDataFile(
Excel String Cell FileName,
Excel String Cell Path,
Excel String Cell KeyTag,
XLRange KeyIds)


C++ Syntax


static std::string KeyToDataFile(
std::string FileName,
std::string Path,
std::string KeyTag,
CTRangeDataCPP KeyIds);


DotNET Syntax


System.String CTGridToolsSA.KeyToDataFile(
System.String FileName,
System.String Path,
System.String KeyTag,
CTRangeData KeyIds);

Parameter data types

ArgNameArgTypeIsKey
FileNameStringFALSE
PathStringFALSE
KeyTagStringFALSE
KeyIdsRangeTRUE


Example Inputs

The first column represents the name of the parameters. The second column specifies whether the parameters are optional or not. Finally the last column provides some sample input data.
Function call input string-keys are always in the format : "NAME.EXTTAG.TICKER" The "EXTTAG.TICKER" part is determined from the output of other, capetools, object creation functions.


ArgNameIsOptional (Excel only)Example
FileNameFALSECT.YC.KeyToDataFile.xml
PathTRUEC:\
KeyTagTRUEOBJ3#
KeyIdsFALSEKeyIdsNAME.EXTTAG.TICKER (from a function call)


Example function usage


The C# example below contains all the sub-function calls leading up to this function call. As a result, the example can contain a lot of code.

The VB.NET, J#, C++.NET, Java, Excel VBA, Visual Basic 6 (via COM) and C++ examples below contain function code stubs for the calls leading up to this function call. However, the function call for this function is displayed.
You can easily reproduce the stub functions code from the C# example.


If you are accessing this functrion via the MiniXL libraries, this function is present within the CT.QL.Utils20 MiniXL Excel Addin.

Within our Excel Example Addin Generator, we have used the following QuantTools sub-functions in order to prepare the arguments needed to call the KeyToDataFile() function. If you are executing this function via the MiniXL libraries, the module addin name, (in brackets, to the right of the sub-functions listed below), indicates the MiniXL library in which the sub-function is held. You will need to load this library into your Excel session (along with any other libraries that the sub-function call within the addin requires (ie - CT.QT.Utils20 addin in almost all cases) in order for the example to compute successfully.

These are the financial QuantTools sub-function calls that are used within the examples :





The objects generated by these sub-functions are inter-connected in the following way :




The following four examples demostrate calling this function within a Microsoft .NET environment

The following four examples demostrate calling this function within a non .NET environment

The following is a sample output from executing the KeyToDataFile() function call


Saved

Copyright (c) 2003-2007 CapeTools - All Rights Reserved.