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Implement Chain Query by Self-Referential Interfaces

huangzhtaohuangzhtao Member Iven HuangOrganization: bitProject: use ice to construct a frame work for financial
Hello everyone,
I want to implement a "chain query" function, in some query objects: query.filter("condition1").filter("condition2").orderBy("Attribute1").
I found "Self-Referential Interfaces" in the documentation may help me, and I define .ice like this:

interface Query{
idempotent Query* filter(string condition);
idempotent Query* orderBy(string attribute);

When going into coding the servant, I don't know how to return Query*(or the proxy to the Query interface).
Am I doing the right way? Can anybody help me?

Best regards!


  • benoitbenoit Rennes, FranceAdministrators, ZeroC Staff Benoit FoucherOrganization: ZeroC, Inc.Project: Ice ZeroC Staff

    You can use the Ice::ObjectAdapter::createProxy method to create the proxy and then cast it to a Query proxy, for example:
    public QueryPrx filter(String str, Ice.Current current)
         return QueryPrxHelper.uncheckedCast(current.adapter.createProxy(current.id));

    Note however that each filter/orderBy call will end up making a remote Ice invocation... which can be costly. A better approach might be to create those Query objects locally and once created pass it over to the server for execution.

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