TradeStation Open Platform

Developers can add an input that requires the user to type in a text string, which is then tested against another text string built into the rules of the EasyLanguage document, allowing the document to work only if the two strings are equal.

Example
Input: Password(" ");
If UpperStr(Password) = "58926Bob" then begin
Plot1(Close,"Close");
End;

EasyLanguage has a function called CustomerID which can be accessed to allow the use of an EasyLanguage document only by a specified end user.

Example
If CustomerID = 123456 then begin
Plot1(Close,"Close");
End;

A developer might find it preferable to allow his EasyLanguage document to function only on a specific symbol by using the GetSymbolName function.

Example
If GetSymbolName = "ABCD" then begin
Plot1(Close,"Close");
End;

The use of an EasyLanguage document can be date-limited by comparing the date of a bar against a date specified in the EasyLanguage code, demonstrated with the following example:

Example
{ Limited usage to December 31 of 2001 }
If Date <= 1011231 then begin
{ place date restricted code within the begin-end block }
Plot1(Close,"Close");
End;

The effectiveness of an EasyLanguage document can depend on the data compression being used by the chart to which it is applied. BarType and BarInterval are EasyLanguage functions available for this very purpose.

The following restricts processing of the EasyLanguage document to a daily chart.

Example
If BarType = 2 then begin
Plot1(Close,"Close");
End;

The following restricts processing of the EasyLanguage document to a 5-minute chart.

If BarType = 1 and BarInterval = 5 then begin
Plot1(Close,"Close");
End;

EasyLanguage supports DLL's meant for calculation enhancements or simple decrypting. Do not use EasyLanguage to call DLL's that use Windows functions to create user interfaces because crashes may occur. In general, DLL functions should not attempt to interrupt the processing of EasyLanguage while, for example, awaiting user input.

Documentation of the EasyLanguage Extension Software Development Kit (SDK) is available through the TradeStation help menu, and from the link provided in the answer to Question 9 above. This documentation contains sample DLL code. Additionally, complete demonstration projects are available through the EasyLanguage-DLL category of the support forums, at the following link.

https://www.tradestation.com/Discussions/forum.aspx?Forum_ID=213&selCategory=1853&subCategory=EasyLanguage-DLL

Click on the link that says "New Topic" at the page to which the link above takes you. Complete the New Topic form, being sure to type your request for demonstration code in the "Message" box. Of course, should you have other questions about creation of TradeStation-compatible DLL's, you may post those also. (The support forums are open to all TradeStation clients, who may view and reply to your posted questions. For this reason, you may wish to remove any proprietary calculations from posted code.)

Any compiler that can export functions with a "standard C" (__stdcall) interface can be used. Developers have created TradeStation-compatible DLL's using Visual C++, Delphi, and PowerBASIC. If you have additional questions about supported compilers, please post in the support forum at the link just provided.

The most common reason for a product failing compatibility testing is due to the use of a built-in function such as ‘LastBarOnChart.’

Part of our compatibility testing guidelines checks that the submission does not have the possibility of overwriting elements in the default work area. This has the potential to cause two problems.

1. If a developer exports the ELD as source-protected, the user could inadvertently overwrite their existing built-in function with a source-protected version that he/she will no longer be able to open.
   
   
2. If TradeStation make changes to the formula for a function for any reason in the future, the user could overwrite the updated version of a function with the older one in the ELD that they import.

Most developers find the best solution is to save a duplicate copy of the built-in functions they use under a different name and change their code to reference the new function. This way, when the ELD is exported, it transfers a uniquely named version of the function and prevents any conflicts.

For example, if the function TL_Exist is used, just open the function and select File – Save EasyLanguage Document As and name it something different such as MyTL_Exist. This will result in two differently named copies of the function file. After creating the unique copy, you would simply replace any references in the ELD code that uses TL_Exist to MyTL_Exist. Subsequently, when you export the ELD, it will transfer MyTL_Exist rather than the built-in function, TL_Exist. This will help to avoid any conflicts.

While this same procedure could be applied for LastBarOnChart, we recommend that developers start modernizing their code to use the reserved word GetAppInfo with the parameter aiRealTimeCalc to determine the status of the calculation (historical or real-time) wherever possible.

All licensed TradeStation Open Platform product developers, regardless of whether you register as an individual or type of legal entity (corporation, partnership or limited liability company), will be deemed a “professional” as defined by the exchanges.

You have the option to choose not to receive any real-time market data services. If you choose not to receive any real-time data, you will receive any delayed data that is offered at no charge by the various exchanges that offer such data. If you do choose to receive real-time market data from an exchange, you will also receive any free delayed data from all other exchanges that offer such data.

During the registration process, you will not be required to select which data services you wish to receive. This can be done during the TradeStation download process, when you will be prompted to select which market data services you wish to receive, and when you will also have time to review the complete list of such services along with their pricing.

Please note that if you wish to qualify for special NASDAQ data services pricing, you must call 954.652.7016 and speak with the TradeStation Add-ons Administrative Assistant.