eSignal offers many development tools that, when combined in a custom solution that’s right for you, make it easy to develop your own monitoring, analysis or trading application or web tools -- the custom applications that spell success for your business. 

In this month’s article, we will explain what Dynamic Data Exchange (DDE), eSignal Formula Script (EFS), Desktop API and Control or Standard API are and where to go on our site to find out more or post any questions you may have. 

DDE
Third party applications that support DDE can receive data from the Data Manager. (Microsoft® Windows® Excel and other applications support DDE.) The Data Manager acts as a server and the other application acts as a client. You can format, arrange and manipulate the data using that application's features. DDE capability is included with all levels of eSignal service, including Basic. Search our KnowledgeBase for more on DDE.

EFS
eSignal’s formula scripting language is an extended version of JavaScript 1.5. In addition to the core functionality of JavaScript 1.5, we’ve added custom extensions, or custom functions, that give the user specific control over the eSignal Advanced Charts. These extensions allow users to access the chart data and develop custom indicators and back testing strategies.

EFS2 is the next evolution in EFS introduced with version 7.9 or higher. EFS2 functions make formula writing more macro-like and easier to code. The new EFS2 engine is backward compatible with formulas developed prior to 7.9.

eSignal has developed the KnowledgeBase as a resource to provide a central location for EFS documentation. There, you will find a complete collection of EFS reference materials, how-to guides, tutorials and an extensive library of EFS formulas developed for eSignal users.

The materials found in the EFS Function Reference folder specifically cover our custom extensions, or EFS. All customers using eSignal Premier services or above automatically have access to our Advanced Charting program, and that includes our formula engine, EFS.

Please go to: http://kb.esignalcentral.com/article.asp?article=1207&p=4 to visit our EFS KnowledgeBase.

Questions that cannot be answered via the KB can be posted to the forums at: http://forum.esignalcentral.com/forumdisplay.php?s=&forumid=22

Desktop API
The Desktop API (aka ActiveX Control) is an ActiveX-like control that uses Microsoft® Windows®-based Component Object Model (COM) technology to provide individual users and third party development groups with a way to exchange data with the eSignal desktop application. The Desktop API can be used with most Windows programming languages, including Microsoft’s .NET environment, and requires eSignal to be running concurrently.

Clients can post to the Desktop API Development forum at:
http://forum.esignalcentral.com/forumdisplay.php?s=&forumid=22

Please note: While we do monitor the forums, these are primarily for user interaction, and a response from a Development Support Team Member should not always be expected. Other users may answer the question rather than an eSignal representative.

Additionally, you can send email requests for help to: http://developer.esignal.com/email/sendMail.asp. This link will send your request directly to the Developer Support Team

Standard API
eSignal's Standard API provides a way for corporations’ third party development groups to access the full set of functions for requesting and processing raw data from the eSignal suite of data servers. eSignal and the third party must agree on a series of contracts and fees before the Standard API is accessible to that third party.

The Standard API supports development using C++. We also provide a wrapper around the Standard API (called the Contol API) that supports development using Visual Basic (VB), C, C++ and C#.

Clients can send email requests for help to http://developer.esignal.com/email/sendMail.asp. Your message will go directly to the Developer Support Team.

Once you've chosen a development path and talked to an eSignal Sales or Business Development representative, you can choose from several more resources that will also be helpful.

1. Feel free to search and post questions on our Desktop API Forum. 
2. Download documentation and coding examples from the ActiveX File Share group.

There are other File Share groups for developers, but most are by invitation only, depending on which development path you choose.

Clients who do not yet have, but are interested in purchasing, one of the APIs should contact our Sales Representatives at 1.888.200.1018. These services are only available to corporate users upon approval.