Outstanding work, Martin!
On Thu, Sep 3, 2015 at 1:49 PM, Martin Desruisseaux <[email protected]> wrote: > Hello all > > We finished the GML (Geographic Markup Language) support for Conversion > and Transformation objects. GML support for ConcatenatedOperation and > PassThroughOperation objects are deferred to a next release. An example > of <gml:Transformation> element can be view at [1]. This example is only > performing a subtraction in the longitude value. > > There is numerous other projects capable to read and write GML > documents. Many projects took the XSD files published by OGC at [2] and > generated automatically the Java classes using JAXB compiler for > instance. Differences between such projects and Apache SIS are: > > 1. SIS hides many GML complexity (e.g. automatic tools applied on GML > tend to generate twice the amount of classes than what exist in the > conceptual model). > 2. SIS objects are ready for use immediately after unmarshalling. They > are not just containers where information has been copied verbatim > from the XML document. The information has been extensively analysed > and processed, so the SIS object is ready for executing map projections. > > Note that point 2 can also be an inconvenient: if SIS has been unable to > process the information (e.g. if it does not recognize a map projection > parameter), an exception may be raised. This behaviour may not be > appropriate if a user just wants to browse the document in a tree > without performing computation. For such cases, we may suggest to use > DOM instead. > > This GML support is new - it did not existed in Geotk (or at least not > in the form of "intelligent" objects). Consequently there is a risk that > we discover some issues after the releases. Nevertheless I wanted to do > this work before the release because GML was known to be broken in some > SIS classes. The intend is to provide a "all or nothing" behaviour: if a > class support GML, at least make that GML valid as much as we can. > > Tomorrow I will complete support of <gml:ProjectedCRS> (the last > "broken" class), then I think we will be done for GML in the proposed > Apache SIS 0.6 release. > > Martin > > > [1] > http://svn.apache.org/repos/asf/sis/branches/JDK8/core/sis-referencing/src/test/resources/org/apache/sis/referencing/operation/Transformation.xml > [2] http://schemas.opengis.net/gml/3.2.1/ > >
