Merging a Composite Object Graph

A graph represents a complete composite data tree instance starting from a single root data node, while a graph part represents one level within a graph. Sublevels are not included in graph parts.

If you do not use the merge command, individual DCN commands first delete each graph part within the cache, then send individual commands to reconstruct the graph within the cache.

Syntax

dcn_request={"pkg":"pkgName","messages": [{"id":"1","op":":merge", "graph":{graphData} }]}

Parameters

• "op":":merge" – merges the specified graph into the cache.
• "graph":{graphData} – identifies the object graph and subgraphs, and data to be merged into the cache.

Examples

these examples include the entire DCN request and use the Mobile Business Object: restdemo Example Project, which you can download and install from the SAP® Community Network: http://scn.sap.com/docs/DOC-8803.

• Merge an object graph into the cache – This example merges Order graph and subgraph data into the existing cached data for the DCNGraphMerge package:

  {"pkg":"DCNGraphMerge","messages":[{"id":"1","op":":merge", 
  "graph":{"Order":[{"orderId":"anOrderId", "customerId":"customer1",
  "orderDate":"2012-01-01"}],"OrderNote":[{"orderNoteId":"orderNote1", 
  "orderId":"anOrderId", "orderNoteText":"note text"}],"Item":[{"itemId":"item1", 
  "orderId":"anOrderId", "productId":"product1", "shipDate":"2012-01-01"}],
  "ItemNote":[{"itemNoteId":"itemNote1", "itemId":"item1", "orderId":"anOrderId", 
  "itemNoteText":"note text", "itemNoteDate":"2012-01-01"}]}}]}

• Merge an object graph into an EIS defined cache partition – this example illustrates the merge command into an EIS defined cache partition named partition1:

  {"pkg":"DCNGraphMerge","messages":[{"id":"1", "partition":"partition1", 
  "op":":merge", "graph":{"Order":[{"orderId":"anOrderId", "customerId":"customer1",
  "orderDate":"2012-01-01"}],"OrderNote":[{"orderNoteId":"orderNote1", "orderId":"anOrderId",
  "orderNoteText":"note text"}],"Item":[{"itemId":"item1", "orderId":"anOrderId", "productId":"product1", 
  "shipDate":"2012-01-01"}],"ItemNote":[{"itemNoteId":"itemNote1", "itemId":"item1", 
  "orderId":"anOrderId", "itemNoteText":"note text", "itemNoteDate":"2012-01-01"}]}}]}
  

• Merge an object graph into the cache and include an expiration date – this example illustrates the merge command with the expiration property (exp), indicating that the data is purged from the SAP Mobile Server cache based on the defined Synchronization Cache Cleanup schedule:

  {"pkg":"DCNGraphMerge","messages":[{"id":"1", "exp":"2013-05-09 17:18:55", "op":":merge", 
  "graph":{"Order":[{"orderId":"anOrderId", "customerId":"customer1","orderDate":"2012-01-01"}],
  "OrderNote":[{"orderNoteId":"orderNote1", "orderId":"anOrderId", "orderNoteText":"note text"}],
  "Item":[{"itemId":"item1", "orderId":"anOrderId", "productId":"product1", "shipDate":"2012-01-01"}],
  "ItemNote":[{"itemNoteId":"itemNote1", "itemId":"item1", "orderId":"anOrderId", 
  "itemNoteText":"note text", "itemNoteDate":"2012-01-01"}]}}]} 

• Merge an object graph into an EIS defined cache partition and include an expiration date – this example illustrates the merge command into an EIS defined cache partition named partition1 with the expiration (exp) property:

  {"pkg":"DCNGraphMerge","messages":[{"id":"1", "partition":"partition1", "exp":"2013-05-09 17:18:55", 
  "op":":merge","graph":{"Order":[{"orderId":"anOrderId", "customerId":"customer1","orderDate":"2012-01-01"}],
  "OrderNote":[{"orderNoteId":"orderNote1", "orderId":"anOrderId", "orderNoteText":"note text"}],
  "Item":[{"itemId":"item1", "orderId":"anOrderId", "productId":"product1", "shipDate":"2012-01-01"}],
  "ItemNote":[{"itemNoteId":"itemNote1", "itemId":"item1", "orderId":"anOrderId", 
  "itemNoteText":"note text", "itemNoteDate":"2012-01-01"}]}}]}