From: Martin D. <mar...@ge...> - 2007-05-16 16:35:06
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Andrea Aime a écrit : >> We can isolate the EPSG database dependencies in a "OracleMathTransformFactory" >> which would wraps the "DefaultMathTransformFactory", inspect the operation name >> for a "(EPSG OP XXXX)" label and substitute the name before to delegate to >> DefaultMathTransformFactory. One more indirection level in the referencing >> module factories! > > Oh hum, was looking at this again, and wondering.... could the plain > name substitution be performed in the wkt parser directly? I mean, we > are already bending it to support the Oracle broken Bursa-Wolf > parameters spec. The WKT parser do not need any external knownledge for supporting the broken Bursa-Wolf parameters. But for name substitution, we need informations from the EPSG database (or from some other external resource). In the example from last email, we have to substitute "British Columbia Albers (EPSG OP 19984)" by "Albers Equal Area". I don't think that there is any regex rule allowing us to guess (in the general case) what the text should be without looking in the EPSG database for code 19984. I would prefer to keep the WKT parser independent of EPSG database. In addition, if Oracle use "British Columbia Albers (EPSG OP 19984)" instead of "Albers Equal Area", maybe they apply this strange usage not only in WKT but on their whole spatial framework. In which case a OracleMathTransformFactory may have some value in order to support the Oracle names at a more fundamental level than WKT parser. Martin |