Invoking upsert and delete Operations Using Data Change Notification

Data change notifications (DCNs) with payload directly update the Unwired Server cache, either with the built-in, direct cache-affecting operations :upsert (update or insert), or with :delete.

Syntax

DCN with payload requires a JavaScript Object Notation (JSON) string (dcn_request) that contains one or more :upsert and :delete operations that are applied to the Unwired Server cache (CDB).

http://unwired_server_host:unwired_server_port(default 8000)/dcn/DCNServlet
? cmd=dcn
&username=userName
&password=password
&domain=domainName
&package=unwired_server_PackageName 
&dcn_request={"pkg":"dummy","messages":[{"id":"1","mbo":"CustomerWithParam","op":":upsert","cols":{"id":"10001","fname":"Adam"}}]}
&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. The default port is 8000.
username – authorized Unwired Server user with permission to modify the MBO.
password – authorized user's password.
domain – Unwired Server domain that contains the package.
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) – this package name is required to support backwards compatibility but ignored. The package value supplied in the header is the package value used by DCN.
- A list of messages (messages). Each message includes:
  - A unique message ID (id) used to report back the status. The values provided for the "id" element of each DCN statement within a DCN request message are used only to identify the corresponding status message in the DCN response, which means you can select any value, including nonnumeric characters. Use unique values, so that responses to the correlated requests can be clearly identified.
  - Mobile business object name (mbo).
  - Operation name (op): an operation name of the specified MBO.
  - Bindings (cols): name and values of operation parameters which are mapped to MBO attributes.
  - Parameters (parameters) : name & values of operation parameters which are unmapped
    Note: For DCN with payload, parameter names must correspond to the attributes of the MBO.
dcn_filter – (optional) the custom filter used to preprocess the DCN request and postprocess the DCN status message any JSON strings. By default, Unwired Server expects all DCN requests to be a valid JSON string. A DCN filter can be used to convert client specific DCN request strings to a valid JSON string as governed by the filter implementation.
ppm – personalization parameters (for either the server or client side) that need to be explicitly defined in the DCN request. The format must conform to the JSON messaging synchronization format, which is a Base64-encoded map of personalization parameters. For example, for runtime credentials sent via DCN, the PPM might be:
```
base64encode("{\"username\":\"supAdmin\",\"password\":\"test\"}");
```

Examples

Upsert example with header – this DCN contains a single :upsert operation that updates or inserts (upserts) data in the Unwired Server cache for the Department MBO.

http://dsqavm5:8000/dcn/DCNServlet?cmd=dcn&username=
supAdmin&password=s3pAdmin&package=dept:1.0&domain=default&dcn_request=
{"pkg":"dummy","messages":[{"id":"1","mbo":"Department","op":":upsert",
"cols":{"dept_id":"2","dept_name":"D2","dept_head_id":"501"}}]}

Upsert example without header – this JSON string included in a DCN contains a single :upsert operation that updates or inserts (upserts) data in the Unwired Server cache for the Department MBO.

dcn_request={"pkg":“TestPackage",
"messages":
	[{"id":"1","mbo":"Department",
		"op":":upsert",
		"cols":{"DepartmentID":"3333",
				 "DepartmentName":"Test Value",
									"DepartmentHeadID":"501"}}]
}

Delete example with header – this DCN example deletes a row of data from the Unwired Server cache for the Department MBO:

http://dspevm5:8000/dcn/DCNServlet?cmd=dcn&username=
supAdmin&password=s3pAdmin&package=dept:1.0&domain=default&dcn_request=
{"pkg":"dummy","messages":[{"id":"1","mbo":"Department","op":":delete",
"cols":{"dept_id":"2"}}]}

Delete example without header – this example JSON string included in the DCN sent to Unwired Server, deletes a row of data from the Unwired Server cache for the Department MBO:
```
dcn_request={"pkg":“TestPackage",
	"messages":[{"id":"1","mbo":"Department",
"op":":delete",
	"cols":{"DepartmentID":"3333"}}]}
```

Usage

Follow these guidelines when constructing a DCN:

The format of non string data is the same as parameter default values in Unwired WorkSpace. For example, specify timestamp values in a format similar to 2009-03-04T17:03:00+05:30.
The :upsert operation requires:
- All MBO primary key attributes to be present in the payload.
- Any other MBO attributes used in the upsert.
- All columns in the operation use attribute names (not the column names to which they are mapped).
The :delete operation requires:
- The MBO primary key attribute be present in the payload.
- All columns in the operation use attribute names (not the column names to which they are mapped).