+1  Well done Martin and all involved!

> On Sep 4, 2015, at 10:40 AM, Adam Estrada <[email protected]> wrote:
> 
> 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/
>> 
>> 

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