Developing DataSnap Applications

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The DataSnap technology continues to evolve, as the demands for distributed computing increase. The technology behind DataSnap has moved beyond the approach of remoting data through the Microsoft COM/DCOM to a more open communication approach based on TCP/IP. This evolution has allowed the DataSnap technology to expand its capabilities in order to include a complete middleware technology. One of the key features of the technology is that it is fast: fast to build, fast to deploy, and fast to execute in production.

DataSnap now has expanded capabilities, allowing the technology to work within almost any standards-based infrastructure. While the latest DataSnap is still backwards-compatible with the COM/DCOM approach, it now has the ability to communicate natively through TCP/IP, and alternatively through HTTP or HTTPS. At the same time, the business logic found in the DataSnap servers can be broadcast as RESTful services.

There are no additional charges to USE or DEPLOY the DataSnap technology.

High-Level Overview of DataSnap

DataSnap Connectors for Mobile Devices

You can now create applications for mobile devices such as the iPhone (iOS), Android (Java) devices, Blackberry (Java) devices, and Windows Phone 7 (C# Silverlight).

For more information, see:

• Getting Started with DataSnap Mobile Connectors
  • Getting Started with iOS Objective-C DataSnap Mobile Connector
  • Getting Started with CSharp Silverlight DataSnap Mobile Connector
  • Getting Started with Java Android DataSnap Mobile Connector
  • Getting Started with Java BlackBerry DataSnap Mobile Connector

DataSnap Proxy Code Example

The Delphi code example DSProxyGenerator_(Delphi) demonstrates how to generate a DataSnap client proxy at run time.

DataSnap Sample Applications Available in Your Product Installation

You can find DataSnap sample applications (that are installed with RAD Studio) by choosing Start | Programs | Embarcadero RAD Studio Rio | Samples. The folders of interest are \Object Pascal\DataSnap\, containing DataSnap multiplatform demos. These DataSnap samples are called, by their folder name:

• DataSnap\Basic -- Basic DataSnap Client and Server Samples
• DataSnap\EchoToChannel -- Echo to Channel Sample

Also there are the Readme.htm files (in the DataSnap subfolders) that provide useful information about using the DataSnap multiplatform demos.

The source for the DataSnap samples in your product installation is checked into a public Subversion repository that can be found on GitHub Repositories To check out a copy of the Subversion repository containing the DataSnap sample applications, go to this Subversion checkout link. Furthermore, you can commit changes to the samples and also update your local copies to acquire the latest changes made to the samples on GitHub Repositories.

The following videos provide more information regarding the DataSnap technology:

• Developing Multi-Tier Solutions Using DataSnap
• DataSnap Tooling
• Building DataSnap Clients and Servers

Topics

• DataSnap Overview and Architecture
• DataExplorer support for DataSnap
• Using a DataSnap Server with an Application (Tutorial)
• DataSnap Server Application
  • Creating a DataSnap Server
  • DataSnap Server Wizard
  • DataSnap REST Application Wizard
  • DataSnap WebBroker Application Wizard
  • Generating DataSnap Server Method Proxies
  • Exposing DataSnap Server Methods
  • Using Callbacks
  • Server Class LifeCycle
  • Monitoring and Controlling DataSnap TCP/IP Connections
• DataSnap Client Application
  • Connecting the Client to DataSnap Server
  • Filtering DataSnap Byte Stream
  • HTTPS Certificate Verification
• Serializing User Objects Using JSON
• DataSnap REST
  • Request Filters
  • JavaScript REST Proxy
  • DBX Parameter Caching
  • REST Heavyweight Callbacks
  • Authentication with a JavaScript Client
  • JavaScript client Sessions
  • DataSnap REST Messaging Protocol
  • REST Client Library
• Authentication and Authorization
• Server Side Session Management
• Cloud Computing with DataSnap
  • OpenSSL Support
  • Azure and Cloud Computing with DataSnap
  • Amazon and Cloud Computing with DataSnap
• Deployment Manager
• DataSnap Connectors for Mobile Devices

See Also

• Tutorial: Using a DataSnap Server with an Application
• Tutorial: DataSnap Application Using an ISAPI DLL Server
• Datasnap.DSConnect.TDSProviderConnection
• Datasnap.DSServer
• Datasnap.DSNames
• Datasnap.DSCommonServer

DataSnap Code Examples and Sample Apps

• Code Example: DSProxyGenerator (Delphi)
• DataSnap.Basic DataSnap Client and Server Sample