Data Change Notification

Data change notification (DCN) is an update mechanism that allows an enterprise information system (EIS) to send data changes to Unwired Server over an HTTP or HTTPS connection using JavaScript Object Notation (JSON).

Two steps are required to send DCN all the way from the EIS to the device: EIS to Unwired Server (DCN), and Unwired Server to device (push synchronization). DCN is independent of device synchronization and can be used both with or without push synchronization to the device.

All DCN commands support both GET and POST methods. The EIS developer creates and sends a DCN to Unwired Server through HTTP GET or POST operations. The portion of the DCN command parameters that come after http://host:8000/dcn/DCNServlet, can all be in POST; any var=name can be in either the URL (GET) or in the POST. The HTTP POST method is more secure than HTTP GET methods; therefore, Sybase recommends that you include the authenticate.password parameter in the POST method, as well as any sensitive data provided for attributes and parameters.

• Data Change Notification Data Flow
  Replication-based synchronization (RBS) data flow for regular DCN differs slightly from message-based synchronization (MBS).
• Data Change Notification With Payload and Without Payload
  Understand the differences between DCN with payload and DCN without payload.
• Information Roadmap for Implementing Data Change Notification
  This section describes additional tasks you must perform to effectively implement DCN and WF-DCN in an end-to-end unwired enterprise environment.
• Implementing Data Change Notification
  Follow the syntax desribed in this section to implement DCN with payload, DCN without payload, and WF-DCN.
• Basic HTTP Authentication
  When you use http://<host>:8000/dcn/DCNServlet, the user authentication is done by Unwired Server extracting the user information from the request parameter.
• Non HTTP Authentication Workflow DCN Request
  You can also send Mobile DCN requests that are not authenticated.
• Data Change Notification Requirements and Guidelines
  Familiarize yourself with data change notification (DCN) requirements before implementing DCN.
• Data Change Notification Results
  Each binding in a data change notification (DCN) request is associated with an ID. The result status of the DCN request is returned in JavaScript Object Notation (JSON) format, and includes a list of IDs followed by a Boolean success field and status message, in case of error.
• Data Change Notification Filters
  Data change notification (DCN) requests need not always be in the format Unwired Server expects.
• Workflow DCN Design Approach and Sample Code
  Understand the design approach for both WF-DCN with and without payload, and view samples for each approach.