Invoking Operations Through Data Change Notification

Data change notifications (DCNs) can instruct Unwired Server to invoke a mobile business object (MBO) operation with a set of specified parameters. Changes to the Unwired Server cache are dependent on the operation’s specified behavior, which was defined during MBO development.

These examples show DCN without payload.

Syntax

DCNs that invoke operations require a JavaScript Object Notation (JSON) string (dcn_request) that contains information about the MBO operation:

http://unwired_server.sybase.com:unwired_server_port/onepage/servlet/UWPServlet?
&cmd=dcn
&username=userName
&password=password
&package=unwired_server_PackageName 
&dcn_request={"pkg":“TestPackage",
	"messages":[{"id":"1","mbo":"mboName","op":“operationName",
  "cols":{"operationParameters"}}]}
&dcn_filter=fully_qualified_name_of_dcn_filter

Parameters

unwired_server – Unwired Server host name to which the DCN is issued.
unwired_server_port – Unwired Server port number
&username – authorized Unwired Server user with permission to modify the MBO.
&password – authorized user's password.
&package – Unwired Server package that contains the MBO. The format is package:version. For example, e2e_package:1.0.
&dcn_request – the JSON string that contains operation name and parameters, which must include:
- Package name (pkg)
- A list of messages (messages), where each message includes:
  - A message ID (id) used to report back the status.
  - Mobile business object name (mbo).
  - Operation name (op): an operation name of the specified MBO, or an alternate read operation.
  - Bindings (cols): operation parameter names and values covering at least all primary key attributes of the MBO.
(Optional) &dcn_filter – custom filter used to convert any JSON strings. By default, Unwired Server expects all DCN requests to be a valid JSON string. Use the DCN filter to convert incoming DCN request strings to a valid JSON string.

Examples

MBO operation invocation – This JSON string (included in a DCN request) invokes the Department MBO's UpdateDepartment operation to update the department ID, Name, and HeadID:

{"pkg":“TestPackage",
	"messages":[{"id":"1","mbo":"Department","op":“UpdateDepartment",
  "cols":{“UpdateDepartment_department_DepartmentID":"3333",
     	“UpdateDepartment_department_DepartmentName":“My Department",
		“UpdateDepartment_department_DepartmentHeadID":"501"}}]}

Multiple operations in one DCN – This example includes multiple messages within one DCN included in the JSON message array:

dcn_request={"pkg":“TestPackage",
	"messages":[
	{"id":"1","mbo":"Department","op":“UpdateDepartment",
   "cols":{“UpdateDepartment_department_DepartmentID":"3333",
     	“UpdateDepartment_department_DepartmentName":“My Department",
		“UpdateDepartment_department_DepartmentHeadID":"501"}}
   {"id":“2","mbo":“AnotherMBO","op":":upsert",
	 "cols":{“AnotherMBOID":“99",
           “MyColumn":“Test ValueMy”}}]}

Usage

A DCN that invokes an operation follows these rules:

All parameters used in the MBO operation must be included.
All columns used in the operation must use the MBO parameter name.
Any explicit value specified in the DCN request takes precedence over a personalized value. To use a personalized value in DCN processing, do not include the personalized parameter name and its value in the DCN request. The personalized value is then inferred by Unwired Server and added to the supplied bindings. Similarly, omit parameters with default values to use previously specified default values.