the most important eco ii enhancements can be summarized as follows
- support for scalable, distributed applications
- support for asp.net (both web forms and web services)
- support for mapping from existing databases
- overall ease-of-use enhancements to make life in the eco space easier
scalable, distributed applications
most importantly, eco ii is now enterprise scalable. where the first version was a client/server solution, eco ii supports both client/server and remote solutions. there are several possible architectures, out of the box, for building scalable asp.net or winforms applications. synchronizing multiple object caches i.e. ecospaces, either in the same process or in multiple separate processes, is managed by the new extended persistencemapper. the synchronizing persistence mapper can in it self be executing within the same process or, more likely, in a process at a server.
eco ii and asp.net
using delphi 2005 we can now combine eco ii and asp.net, for use in both asp.net web forms and asp.net web services. the borland db web controls can expose objects within an ecospace through binding to the new ecodatasource component, which uses an ocl expression to provide a datasource, and can be used to produce visual data-aware asp.net web form applications. the same can be done with any regular native asp.net web control. eco components, such as the expressionhandler, provide a list of elements that can be used as a dataset, and hence binds any asp.net components including datalist and datagrid.
since requests in asp.net applications are stateless, we can maintain the ecospace state either in the session or at the application level.
eco ii uses optimistic locking, and when a conflict occurs, conflict resolution is used to determine the correct actions. specifically, when an eco space detects that a value in the actual database is different from the supposed "old value" in the ecospace, it registers a conflict in an internal list in the ecospace. the developer can call retrievechanges for any changes done by other ecospaces, and getchanges for any unresolved conflicts that can then be resolved (usually interactively by the end user).
delphi 2005 eco ii asp.net web form at design-time
