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Re: [Branch ~dhis2-devs-core/dhis2/trunk] Rev 1946: Modified DXF, coordinates are now nested within feature, and feature type is an attribute of feat...

To: Jason Pickering <jason.p.pickering@xxxxxxxxx>
From: Bob Jolliffe <bobjolliffe@xxxxxxxxx>
Date: Wed, 2 Jun 2010 13:23:38 +0100
Cc: dhis2-devs <dhis2-devs@xxxxxxxxxxxxxxxxxxx>
In-reply-to: <AANLkTimNSze3vYF1VrGOQFdBhhCHwQYKmydD1onAyGCO@mail.gmail.com>

Hi Jason

On 2 June 2010 12:56, Jason Pickering <jason.p.pickering@xxxxxxxxx> wrote:
> Although it (maybe) is a  bit overkill to implement GML for our
> purposes, it would probably be a good idea to at least look at some
> examples and follow what we can..
>
> http://openlayers.org/dev/examples/gml/ for example

I'm not yet convinced that is too much overkill to implement a small
featureset dialect.  I guess the main problem is there would be a few
redundant elements (<gml:outerBoundaryIs>, <gml:LinearRing> etc) which
we would not be doing anything useful with except just pushing them in
and out of the xml to make it valid gml.  So in our concise gml-like
markup Lars has just stripped these out and gone straight from the
feature to the coordinates.  I can see his point.

But I would argue that
(i)  compared to the bulk of coordinates data, the proportion of
overhead introduced by the extra elements is not too significant; and
(ii) we can still be as concise as our underlying model allows re the
actual storage.

But its a matter of gaining on the swings and losing on the
roundabouts.  What we gain is that any third party app can look at the
GIS info in our dxf export and be able to understand it without too
much additional documentation (the benefit of reuse).  The cost is
that from a dhis internal perspective there's some redundancy in the
markup.

Lars would argue that we can always do a gml export of our dxf gis
data anyway by passing it through a dxf2gml transformer.

Mind you, to do this we would have to define a simple
dxf:FeatureCollection (schema) to host the transformed gml elements
anyway (like the wfs in the example you gave).  So if we're going to
do that for the purpose of export my sense is that we might as well
just use the <dxf:Feature> ... gml stuff ... </dxf:Feature> directly
in the <dxf:OrganisationUnit> in the first place.

I'm happy to have it as it is for the moment.  Its pretty cool to be
able to read this stuff in anyway.  When I get back to motivating
dxfv2 (real soon now) I'll revisit the issue.

>
> It might be a good idea to declare the coordinate system someplace as
> well (EPSG 4326 so far).

Don't know enough about this stuff, but is there any immediate
prospect of us using anything but EPSG 4326 ?

Cheers
Bob

>
> Regards,
> JPP
>
>
>
> On Wed, Jun 2, 2010 at 12:39 PM, Bob Jolliffe <bobjolliffe@xxxxxxxxx> wrote:
>> Minor tweak:  suggest <coordinate> is renamed <coordinates>.. You are
>> storing multiple coordinates in this element.
>>
>> On 2 June 2010 10:52,  <noreply@xxxxxxxxxxxxx> wrote:
>>> ------------------------------------------------------------
>>> revno: 1946
>>> committer: Lars <larshelg@larshelg-laptop>
>>> branch nick: trunk
>>> timestamp: Wed 2010-06-02 11:51:11 +0200
>>> message:
>>>  Modified DXF, coordinates are now nested within feature, and feature type is an attribute of feature.
>>> modified:
>>>  dhis-2/dhis-services/dhis-service-importexport/src/main/java/org/hisp/dhis/importexport/dxf/converter/OrganisationUnitConverter.java
>>>  dhis-2/dhis-services/dhis-service-importexport/src/test/resources/dxfOrganisationUnits.xml
>>>
>>>
>>> --
>>> lp:dhis2
>>> https://code.launchpad.net/~dhis2-devs-core/dhis2/trunk
>>>
>>> Your team DHIS 2 developers is subscribed to branch lp:dhis2.
>>> To unsubscribe from this branch go to https://code.launchpad.net/~dhis2-devs-core/dhis2/trunk/+edit-subscription
>>>
>>> === modified file 'dhis-2/dhis-services/dhis-service-importexport/src/main/java/org/hisp/dhis/importexport/dxf/converter/OrganisationUnitConverter.java'
>>> --- dhis-2/dhis-services/dhis-service-importexport/src/main/java/org/hisp/dhis/importexport/dxf/converter/OrganisationUnitConverter.java        2010-05-29 16:06:56 +0000
>>> +++ dhis-2/dhis-services/dhis-service-importexport/src/main/java/org/hisp/dhis/importexport/dxf/converter/OrganisationUnitConverter.java        2010-06-02 09:51:11 +0000
>>> @@ -65,10 +65,10 @@
>>>     private static final String FIELD_ACTIVE = "active";
>>>     private static final String FIELD_COMMENT = "comment";
>>>     private static final String FIELD_GEO_CODE = "geoCode";
>>> -    private static final String FIELD_COORDINATES = "coordinates";
>>>     private static final String FIELD_COORDINATE = "coordinate";
>>> -    private static final String FIELD_FEATURE_TYPE = "featureType";
>>> +    private static final String FIELD_FEATURE = "feature";
>>>     private static final String FIELD_LAST_UPDATED = "lastUpdated";
>>> +    private static final String ATTRIBUTE_TYPE = "type";
>>>
>>>     // -------------------------------------------------------------------------
>>>     // Constructor
>>> @@ -126,9 +126,8 @@
>>>                 writer.writeElement( FIELD_ACTIVE, String.valueOf( unit.isActive() ) );
>>>                 writer.writeElement( FIELD_COMMENT, unit.getComment() );
>>>                 writer.writeElement( FIELD_GEO_CODE, unit.getGeoCode() );
>>> -                writer.writeElement( FIELD_FEATURE_TYPE, unit.getFeatureType() );
>>>
>>> -                writer.openElement( FIELD_COORDINATES );
>>> +                writer.openElement( FIELD_FEATURE, ATTRIBUTE_TYPE, unit.getFeatureType() );
>>>                 for ( String coordinate : unit.getCoordinatesAsCollection() )
>>>                 {
>>>                     writer.writeElement( FIELD_COORDINATE, coordinate );
>>> @@ -182,11 +181,11 @@
>>>                 reader.moveToStartElement( FIELD_GEO_CODE );
>>>                 unit.setGeoCode( reader.getElementValue() );
>>>
>>> -                reader.moveToStartElement( FIELD_FEATURE_TYPE );
>>> -                unit.setFeatureType( reader.getElementValue() );
>>> +                reader.moveToStartElement( FIELD_FEATURE );
>>> +                unit.setFeatureType( reader.getAttributeValue( ATTRIBUTE_TYPE ) );
>>>
>>>                 Collection<String> coordinates = new ArrayList<String>();
>>> -                while ( reader.moveToStartElement( FIELD_COORDINATE, FIELD_COORDINATES ) )
>>> +                while ( reader.moveToStartElement( FIELD_COORDINATE, FIELD_FEATURE ) )
>>>                 {
>>>                     coordinates.add( reader.getElementValue() );
>>>                 }
>>>
>>> === modified file 'dhis-2/dhis-services/dhis-service-importexport/src/test/resources/dxfOrganisationUnits.xml'
>>> --- dhis-2/dhis-services/dhis-service-importexport/src/test/resources/dxfOrganisationUnits.xml  2010-05-25 17:36:53 +0000
>>> +++ dhis-2/dhis-services/dhis-service-importexport/src/test/resources/dxfOrganisationUnits.xml  2010-06-02 09:51:11 +0000
>>> @@ -11,12 +11,11 @@
>>>  <active>true</active>
>>>  <comment>Comment</comment>
>>>  <geoCode>GeoCode</geoCode>
>>> -<featureType>MultiPolygon</featureType>
>>> -<coordinates>
>>> +<feature type="MultiPolygon">
>>>  <coordinate>11.11,22.22 33.33,44.44 55.55,66.66</coordinate>
>>>  <coordinate>77.77,88.88 99.99,11.11 22.22,33.33</coordinate>
>>>  <coordinate>44.44,55.55 66.66,77.77 88.88,99.99</coordinate>
>>> -</coordinates>
>>> +</feature>
>>>  <lastUpdated>2010-01-01</lastUpdated>
>>>  </organisationUnit>
>>>  <organisationUnit>
>>> @@ -30,12 +29,11 @@
>>>  <active>true</active>
>>>  <comment>Comment</comment>
>>>  <geoCode>GeoCode</geoCode>
>>> -<featureType>MultiPolygon</featureType>
>>> -<coordinates>
>>> +<feature type="MultiPolygon">
>>>  <coordinate>11.11,22.22 33.33,44.44 55.55,66.66</coordinate>
>>>  <coordinate>77.77,88.88 99.99,11.11 22.22,33.33</coordinate>
>>>  <coordinate>44.44,55.55 66.66,77.77 88.88,99.99</coordinate>
>>> -</coordinates>
>>> +</feature>
>>>  <lastUpdated>2010-01-01</lastUpdated>
>>>  </organisationUnit>
>>>  <organisationUnit>
>>> @@ -49,12 +47,11 @@
>>>  <active>true</active>
>>>  <comment>Comment</comment>
>>>  <geoCode>GeoCode</geoCode>
>>> -<featureType>MultiPolygon</featureType>
>>> -<coordinates>
>>> +<feature type="MultiPolygon">
>>>  <coordinate>11.11,22.22 33.33,44.44 55.55,66.66</coordinate>
>>>  <coordinate>77.77,88.88 99.99,11.11 22.22,33.33</coordinate>
>>>  <coordinate>44.44,55.55 66.66,77.77 88.88,99.99</coordinate>
>>> -</coordinates>
>>> +</feature>
>>>  <lastUpdated>2010-01-01</lastUpdated>
>>>  </organisationUnit>
>>>  </organisationUnits>
>>>
>>>
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>>>
>>
>> _______________________________________________
>> Mailing list: https://launchpad.net/~dhis2-devs
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>>
>
>
>
> --
> --
> Jason P. Pickering
> email: jason.p.pickering@xxxxxxxxx
> tel:+260968395190
>

References

[Branch ~dhis2-devs-core/dhis2/trunk] Rev 1946: Modified DXF, coordinates are now nested within feature, and feature type is an attribute of feat...
From: noreply, 2010-06-02
Re: [Branch ~dhis2-devs-core/dhis2/trunk] Rev 1946: Modified DXF, coordinates are now nested within feature, and feature type is an attribute of feat...
From: Bob Jolliffe, 2010-06-02
Re: [Branch ~dhis2-devs-core/dhis2/trunk] Rev 1946: Modified DXF, coordinates are now nested within feature, and feature type is an attribute of feat...
From: Jason Pickering, 2010-06-02