Example name:	ReturnType of DataSet's DataTables' records
Description:	Shows how to use WebORB's ReturnType attribute in server-side code to tell WebORB to serialize a DataSet's DataTables' records as instances of a given client-side type.
Prerequisites:	ReturnType of DataTable's records
Client-side code:	Browse  Download
Server-side code:	Browse  Download
Feature availability:	WebORB for .NET Development Mode WebORB for .NET Community Edition WebORB for .NET Enterprise Edition
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Key points:	WebORB serializes a DataSet to the Flex client as an instance of the dynamic ActionScript class Object. Each of the DataSet's DataTables is stored in dynamic properties named Table1, Table2, Table3, etc. WebORB serializes each DataTable in a DataSet as an Array (or ArrayCollection). By default, each record in each array is serialized to an ActionScript object, with the record's properties being mapped to dynamic name/value pairs. It is often useful to map each record to an instance of given client-side class, instead of a dynamic object. Using the ReturnType attribute tells WebORB to serialize a DataSet's DataTables' records as instances of a given client-side type. Server-side code: Line 6: 'using Weborb.Service' declares the ReturnType attribute Line 45-57: Defines the returnsNull() method, which serves no purpose other than to tell WebORB that its code generator should generate a client-side Data Transfer Object class for this server-side class. The ReturnType attribute, above, refers to this WewbORB-generated Data Transfer Object class. Line 61: '[ReturnType("examples.weborb.Customer")]' tells WebORB to map all records in the following method's returned DataSet's DataTables to instances of the client-side class, examples.weborb.Customer. Line 73-87: Defines the server-side Customer class mentioned above. Client-side code: examples.weborb.vo.Customer.as: Defines the Data Transfer Object class generated by WebORB from the server-side Customer class, as described above. main.mxml, lines 31-32: defines customersAC, an ArrayCollection, and binds its 'source' to the dynamic property Table1 in the object that is the result of the remote service call to CustomerService.getCustomersAsDataSet(). main.mxml, line 41: binds the DataGrid's 'dataprovider' to 'customersAC', and hence to the result of the remote service call.

Things to try:	Instead of relying on WebORB's code generator to produce a client-side Customer class, (a) delete the definition of the Customer class and the returnNull() method from CustomerService.cs, and (b) define a Customer class on the client-side yourself. What are the advantages and disadvantages of each approach? Delete the definition of the Customer class and the returnNull() method from CustomerService.cs, and also delete the 'ReturnType' attribute from getCustomers()'s definition. What corresponding changes are required in the client-side code? Why?
See also:	WebORB: DataTable row class mapping WebORB: ArrayCollection mapping .NET: DataTable class Adobe: DataGrid control
Screencast:	[none]
Errata:	None yet known.