3 New Methods in Connect

Connect no longer contains instances³ of DAS, DDS, et c., that can hold values returned from the server. Instead it has methods which return the objects using value-result parameters. Here are the new methods:

    virtual void request_das(DAS &das) throw(Error, InternalErr);
    virtual void request_das_url(DAS &das) throw(Error, InternalErr);

    virtual void request_dds(DDS &dds, string expr = "") throw(Error, InternalErr);
    virtual void request_dds_url(DDS &dds) throw(Error, InternalErr);

    virtual void request_data(DataDDS &data, string expr = "") throw(Error, InternalErr);
    virtual void request_data_url(DataDDS &data) throw(Error, InternalErr);

Note:

• The methods now take a reference to the object being requested; the return is via this parameter.
• The methods signal errors using exceptions.
• Patrick has added versions that do not modify the URL at all (the ones with the _url suffix).

Other changes: Be sure to scan the Connect documentation for other things that have been deprecated. The Connect class was one of the poorest in libdap. I have reduced it considerably and factored many of the HTTP-specific methods into HTTPConnect and all of the caching into HTTPCache. Also note that cache resource management is not controlled by the Response, HTTPResponse and HTTPCacheResponse classes. Particularly, the release of cache resources is now managed by the Response class and its children.

3.1 Connections removed

In the past libdap included a class that could be used to make a collection of Connect instances. This was used in code like the NetCDF Client Library to store one instance of Connect for each `open file.' That class was called Connections. It has been removed from the library since it makes most sense to just put a copy of it in your project. If you need it, download the NetCDF client library source code (or use subversion) and put copies of Connections.cc and Connections.h in your source.