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Possible bug with ogc:BBOX and two suggestions

Rahkonen Jukka
Hi,
 
I continued to test Kosmo WFS connector and found two issues with the spatial Bounding box (BBOX) filter.  First one is that the name of the filter is ogc:BBOX but Kosmo is generating it as ogc:Bbox.  Another issue is that Kosmo is inserting a polygon geometry into the BBOX filter but it looks that according to standard only Envelope is acceptep.
Here are two excerpts from the Feature Encoding 1.1 standard
 
" The <BBOX> element is defined as a convenient and more compact way of encoding the very common bounding box constraint based on the gml:Envelope geometry. It is equivalent to the spatial operation <Not><Disjoint> … </Disjoint></Not> meaning that the <BBOX> operator should identify all geometries that spatially interact with the box. If the optional <propertyName> element is not specified, the calling service must determine which spatial property is the spatial key and apply the BBOX operator accordingly. "
 
<xsd:complexType name="BBOXType">
<xsd:complexContent>
<xsd:extension base="ogc:SpatialOpsType">
<xsd:sequence>
<xsd:element ref="ogc:PropertyName" minOccurs="0"/>
<xsd:element ref="gml:Envelope"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
 
I have also two suggestions about making the use of WFS even more friendly for the user.  First one is be to make it possible to cache the GetCapabilities document during the session if user wants so. Some servers are slow in generating GetCapabilities but that information does not change often so caching can be considered to be safe.  GvSIG has this option and it can make it much faster to get many separate WFS layers from the same server.  Another suggestion is also implemented in gvSIG and QGIS and it is to to make a shortcut for capturing the extents of the current map and place them into the BBOX filter. Now Kosmo user must create first an editable layer, draw a rectangle, select it and use the geometry for building the Intersects filter.
 
Regards,
 
-Jukka Rahkonen-
 

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Re: Possible bug with ogc:BBOX and two suggestions

Sergio Baños Calvo
Good morning Jukka.

I have revised the BBOX filter and, as you stated in your mail, we're not generating the right request when it's used. I have made the changes to generate a gml:Envelope for that filter (and corrected the filter name) but I don't get it work yet: I'll try it again next weekend to see what's happening.

In respect of your suggestions, I agree that both are very useful: we have added then to the TODO list for the next version, they are pretty simple to implement :).

Regards,

El 12/10/2011 10:20, Rahkonen Jukka escribió:
Hi,
 
I continued to test Kosmo WFS connector and found two issues with the spatial Bounding box (BBOX) filter.  First one is that the name of the filter is ogc:BBOX but Kosmo is generating it as ogc:Bbox.  Another issue is that Kosmo is inserting a polygon geometry into the BBOX filter but it looks that according to standard only Envelope is acceptep.
Here are two excerpts from the Feature Encoding 1.1 standard
 
" The <BBOX> element is defined as a convenient and more compact way of encoding the very common bounding box constraint based on the gml:Envelope geometry. It is equivalent to the spatial operation <Not><Disjoint> … </Disjoint></Not> meaning that the <BBOX> operator should identify all geometries that spatially interact with the box. If the optional <propertyName> element is not specified, the calling service must determine which spatial property is the spatial key and apply the BBOX operator accordingly. "
 
<xsd:complexType name="BBOXType">
<xsd:complexContent>
<xsd:extension base="ogc:SpatialOpsType">
<xsd:sequence>
<xsd:element ref="ogc:PropertyName" minOccurs="0"/>
<xsd:element ref="gml:Envelope"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
 
I have also two suggestions about making the use of WFS even more friendly for the user.  First one is be to make it possible to cache the GetCapabilities document during the session if user wants so. Some servers are slow in generating GetCapabilities but that information does not change often so caching can be considered to be safe.  GvSIG has this option and it can make it much faster to get many separate WFS layers from the same server.  Another suggestion is also implemented in gvSIG and QGIS and it is to to make a shortcut for capturing the extents of the current map and place them into the BBOX filter. Now Kosmo user must create first an editable layer, draw a rectangle, select it and use the geometry for building the Intersects filter.
 
Regards,
 
-Jukka Rahkonen-
 


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[hidden email]
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--

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Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]


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Re: Possible bug with ogc:BBOX and two suggestions

Rahkonen Jukka
Thank you very much for your continuos interest. If you happen to test with my server it has a bug too and at least for the "france" layer BBOX filter wants coordinates in a reversed order which is wrong for that CRS.  Here is an example of a request that works even it is wrong with my server  http://188.64.1.61/cgi-bin/tinyows 
 
<wfs:GetFeature xmlns:ogc="http://www.opengis.net/ogc"
xmlns:gml="
http://www.opengis.net/gml" xmlns:wfs="http://www.opengis.net/wfs"
service="WFS" version="1.1.0" maxFeatures="1000" outputFormat="text/xml; subtype=gml/3.1.1">
<wfs:Query xmlns:tows="
http://www.tinyows.org/"
srsName="urn:ogc:def:crs:EPSG::27582" typeName="tows:france">
<wfs:PropertyName>tows:the_geom</wfs:PropertyName>
<ogc:Filter><ogc:BBOX><ogc:PropertyName>tows:the_geom</ogc:PropertyName>
<gml:Envelope srsName='urn:ogc:def:crs:EPSG::27582'>
<gml:lowerCorner>2150739 500117</gml:lowerCorner>
<gml:upperCorner>2315484 658850</gml:upperCorner>
</gml:Envelope>
</ogc:BBOX></ogc:Filter></wfs:Query></wfs:GetFeature>
 
Request is accepted also with a correct Envelope <gml:lowerCorner>500117 2150739 </gml:lowerCorner> <gml:upperCorner>658850 2315484 </gml:upperCorner> but it does not find anything.
 
You may want to have a try also with the the OpenGEO demo server
 
-Jukka Rahkonen-
 
 
 

Lähettäjä: [hidden email] [mailto:[hidden email]] Puolesta Sergio Baños Calvo
Lähetetty: 13. lokakuuta 2011 11:43
Vastaanottaja: International Kosmo mailing list (english languaje)
Aihe: Re: [Kosmo_int] Possible bug with ogc:BBOX and two suggestions

Good morning Jukka.

I have revised the BBOX filter and, as you stated in your mail, we're not generating the right request when it's used. I have made the changes to generate a gml:Envelope for that filter (and corrected the filter name) but I don't get it work yet: I'll try it again next weekend to see what's happening.

In respect of your suggestions, I agree that both are very useful: we have added then to the TODO list for the next version, they are pretty simple to implement :).

Regards,

El 12/10/2011 10:20, Rahkonen Jukka escribió:
Hi,
 
I continued to test Kosmo WFS connector and found two issues with the spatial Bounding box (BBOX) filter.  First one is that the name of the filter is ogc:BBOX but Kosmo is generating it as ogc:Bbox.  Another issue is that Kosmo is inserting a polygon geometry into the BBOX filter but it looks that according to standard only Envelope is acceptep.
Here are two excerpts from the Feature Encoding 1.1 standard
 
" The <BBOX> element is defined as a convenient and more compact way of encoding the very common bounding box constraint based on the gml:Envelope geometry. It is equivalent to the spatial operation <Not><Disjoint> … </Disjoint></Not> meaning that the <BBOX> operator should identify all geometries that spatially interact with the box. If the optional <propertyName> element is not specified, the calling service must determine which spatial property is the spatial key and apply the BBOX operator accordingly. "
 
<xsd:complexType name="BBOXType">
<xsd:complexContent>
<xsd:extension base="ogc:SpatialOpsType">
<xsd:sequence>
<xsd:element ref="ogc:PropertyName" minOccurs="0"/>
<xsd:element ref="gml:Envelope"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
 
I have also two suggestions about making the use of WFS even more friendly for the user.  First one is be to make it possible to cache the GetCapabilities document during the session if user wants so. Some servers are slow in generating GetCapabilities but that information does not change often so caching can be considered to be safe.  GvSIG has this option and it can make it much faster to get many separate WFS layers from the same server.  Another suggestion is also implemented in gvSIG and QGIS and it is to to make a shortcut for capturing the extents of the current map and place them into the BBOX filter. Now Kosmo user must create first an editable layer, draw a rectangle, select it and use the geometry for building the Intersects filter.
 
Regards,
 
-Jukka Rahkonen-
 


_______________________________________________
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[hidden email]
http://lists.saig.es/mailman/listinfo/kosmo_int

--

Sergio Baños Calvo

Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]


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Re: Possible bug with ogc:BBOX and two suggestions

Sergio Baños Calvo
Hi again, Jukka.

I have tested against the OpenGEO server and it works like a charm :). The tests I did were done against your TinyOWS server and they returned always "No data found".

Regards,

El 13/10/2011 11:00, Rahkonen Jukka escribió:
Thank you very much for your continuos interest. If you happen to test with my server it has a bug too and at least for the "france" layer BBOX filter wants coordinates in a reversed order which is wrong for that CRS.  Here is an example of a request that works even it is wrong with my server  http://188.64.1.61/cgi-bin/tinyows 
 
<wfs:GetFeature xmlns:ogc="http://www.opengis.net/ogc"
xmlns:gml="
http://www.opengis.net/gml" xmlns:wfs="http://www.opengis.net/wfs"
service="WFS" version="1.1.0" maxFeatures="1000" outputFormat="text/xml; subtype=gml/3.1.1">
<wfs:Query xmlns:tows="
http://www.tinyows.org/"
srsName="urn:ogc:def:crs:EPSG::27582" typeName="tows:france">
<wfs:PropertyName>tows:the_geom</wfs:PropertyName>
<ogc:Filter><ogc:BBOX><ogc:PropertyName>tows:the_geom</ogc:PropertyName>
<gml:Envelope srsName='urn:ogc:def:crs:EPSG::27582'>
<gml:lowerCorner>2150739 500117</gml:lowerCorner>
<gml:upperCorner>2315484 658850</gml:upperCorner>
</gml:Envelope>
</ogc:BBOX></ogc:Filter></wfs:Query></wfs:GetFeature>
 
Request is accepted also with a correct Envelope <gml:lowerCorner>500117 2150739 </gml:lowerCorner> <gml:upperCorner>658850 2315484 </gml:upperCorner> but it does not find anything.
 
You may want to have a try also with the the OpenGEO demo server
 
-Jukka Rahkonen-
 
 
 

Lähettäjä: [hidden email] [[hidden email]] Puolesta Sergio Baños Calvo
Lähetetty: 13. lokakuuta 2011 11:43
Vastaanottaja: International Kosmo mailing list (english languaje)
Aihe: Re: [Kosmo_int] Possible bug with ogc:BBOX and two suggestions

Good morning Jukka.

I have revised the BBOX filter and, as you stated in your mail, we're not generating the right request when it's used. I have made the changes to generate a gml:Envelope for that filter (and corrected the filter name) but I don't get it work yet: I'll try it again next weekend to see what's happening.

In respect of your suggestions, I agree that both are very useful: we have added then to the TODO list for the next version, they are pretty simple to implement :).

Regards,

El 12/10/2011 10:20, Rahkonen Jukka escribió:
Hi,
 
I continued to test Kosmo WFS connector and found two issues with the spatial Bounding box (BBOX) filter.  First one is that the name of the filter is ogc:BBOX but Kosmo is generating it as ogc:Bbox.  Another issue is that Kosmo is inserting a polygon geometry into the BBOX filter but it looks that according to standard only Envelope is acceptep.
Here are two excerpts from the Feature Encoding 1.1 standard
 
" The <BBOX> element is defined as a convenient and more compact way of encoding the very common bounding box constraint based on the gml:Envelope geometry. It is equivalent to the spatial operation <Not><Disjoint> … </Disjoint></Not> meaning that the <BBOX> operator should identify all geometries that spatially interact with the box. If the optional <propertyName> element is not specified, the calling service must determine which spatial property is the spatial key and apply the BBOX operator accordingly. "
 
<xsd:complexType name="BBOXType">
<xsd:complexContent>
<xsd:extension base="ogc:SpatialOpsType">
<xsd:sequence>
<xsd:element ref="ogc:PropertyName" minOccurs="0"/>
<xsd:element ref="gml:Envelope"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
 
I have also two suggestions about making the use of WFS even more friendly for the user.  First one is be to make it possible to cache the GetCapabilities document during the session if user wants so. Some servers are slow in generating GetCapabilities but that information does not change often so caching can be considered to be safe.  GvSIG has this option and it can make it much faster to get many separate WFS layers from the same server.  Another suggestion is also implemented in gvSIG and QGIS and it is to to make a shortcut for capturing the extents of the current map and place them into the BBOX filter. Now Kosmo user must create first an editable layer, draw a rectangle, select it and use the geometry for building the Intersects filter.
 
Regards,
 
-Jukka Rahkonen-
 


_______________________________________________
Kosmo_int mailing list
[hidden email]
http://lists.saig.es/mailman/listinfo/kosmo_int

--

Sergio Baños Calvo

Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]



_______________________________________________
Kosmo_int mailing list
[hidden email]
http://lists.saig.es/mailman/listinfo/kosmo_int

--

Sergio Baños Calvo

Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]


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Re: Possible bug with ogc:BBOX and two suggestions

Rahkonen Jukka
Hi,
 
Great. I am sorry about the extra trouble but I managed to find the TinyOWS bug only some hours after I sent mail to Kosmo list. A rule of thumb with WFS 1.1.0 seems to be that if something goes wrong it is best to test first with reversed coordinates.
 
-Jukka-
 

Lähettäjä: [hidden email] [mailto:[hidden email]] Puolesta Sergio Baños Calvo
Lähetetty: 13. lokakuuta 2011 12:12
Vastaanottaja: International Kosmo mailing list (english languaje)
Aihe: Re: [Kosmo_int] Possible bug with ogc:BBOX and two suggestions

Hi again, Jukka.

I have tested against the OpenGEO server and it works like a charm :). The tests I did were done against your TinyOWS server and they returned always "No data found".

Regards,

El 13/10/2011 11:00, Rahkonen Jukka escribió:
Thank you very much for your continuos interest. If you happen to test with my server it has a bug too and at least for the "france" layer BBOX filter wants coordinates in a reversed order which is wrong for that CRS.  Here is an example of a request that works even it is wrong with my server  http://188.64.1.61/cgi-bin/tinyows 
 
<wfs:GetFeature xmlns:ogc="http://www.opengis.net/ogc"
xmlns:gml="
http://www.opengis.net/gml" xmlns:wfs="http://www.opengis.net/wfs"
service="WFS" version="1.1.0" maxFeatures="1000" outputFormat="text/xml; subtype=gml/3.1.1">
<wfs:Query xmlns:tows="
http://www.tinyows.org/"
srsName="urn:ogc:def:crs:EPSG::27582" typeName="tows:france">
<wfs:PropertyName>tows:the_geom</wfs:PropertyName>
<ogc:Filter><ogc:BBOX><ogc:PropertyName>tows:the_geom</ogc:PropertyName>
<gml:Envelope srsName='urn:ogc:def:crs:EPSG::27582'>
<gml:lowerCorner>2150739 500117</gml:lowerCorner>
<gml:upperCorner>2315484 658850</gml:upperCorner>
</gml:Envelope>
</ogc:BBOX></ogc:Filter></wfs:Query></wfs:GetFeature>
 
Request is accepted also with a correct Envelope <gml:lowerCorner>500117 2150739 </gml:lowerCorner> <gml:upperCorner>658850 2315484 </gml:upperCorner> but it does not find anything.
 
You may want to have a try also with the the OpenGEO demo server
 
-Jukka Rahkonen-
 
 
 

Lähettäjä: [hidden email] [[hidden email]] Puolesta Sergio Baños Calvo
Lähetetty: 13. lokakuuta 2011 11:43
Vastaanottaja: International Kosmo mailing list (english languaje)
Aihe: Re: [Kosmo_int] Possible bug with ogc:BBOX and two suggestions

Good morning Jukka.

I have revised the BBOX filter and, as you stated in your mail, we're not generating the right request when it's used. I have made the changes to generate a gml:Envelope for that filter (and corrected the filter name) but I don't get it work yet: I'll try it again next weekend to see what's happening.

In respect of your suggestions, I agree that both are very useful: we have added then to the TODO list for the next version, they are pretty simple to implement :).

Regards,

El 12/10/2011 10:20, Rahkonen Jukka escribió:
Hi,
 
I continued to test Kosmo WFS connector and found two issues with the spatial Bounding box (BBOX) filter.  First one is that the name of the filter is ogc:BBOX but Kosmo is generating it as ogc:Bbox.  Another issue is that Kosmo is inserting a polygon geometry into the BBOX filter but it looks that according to standard only Envelope is acceptep.
Here are two excerpts from the Feature Encoding 1.1 standard
 
" The <BBOX> element is defined as a convenient and more compact way of encoding the very common bounding box constraint based on the gml:Envelope geometry. It is equivalent to the spatial operation <Not><Disjoint> … </Disjoint></Not> meaning that the <BBOX> operator should identify all geometries that spatially interact with the box. If the optional <propertyName> element is not specified, the calling service must determine which spatial property is the spatial key and apply the BBOX operator accordingly. "
 
<xsd:complexType name="BBOXType">
<xsd:complexContent>
<xsd:extension base="ogc:SpatialOpsType">
<xsd:sequence>
<xsd:element ref="ogc:PropertyName" minOccurs="0"/>
<xsd:element ref="gml:Envelope"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
 
I have also two suggestions about making the use of WFS even more friendly for the user.  First one is be to make it possible to cache the GetCapabilities document during the session if user wants so. Some servers are slow in generating GetCapabilities but that information does not change often so caching can be considered to be safe.  GvSIG has this option and it can make it much faster to get many separate WFS layers from the same server.  Another suggestion is also implemented in gvSIG and QGIS and it is to to make a shortcut for capturing the extents of the current map and place them into the BBOX filter. Now Kosmo user must create first an editable layer, draw a rectangle, select it and use the geometry for building the Intersects filter.
 
Regards,
 
-Jukka Rahkonen-
 


_______________________________________________
Kosmo_int mailing list
[hidden email]
http://lists.saig.es/mailman/listinfo/kosmo_int

--

Sergio Baños Calvo

Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]



_______________________________________________
Kosmo_int mailing list
[hidden email]
http://lists.saig.es/mailman/listinfo/kosmo_int

--

Sergio Baños Calvo

Jefe de desarrollos
Sistemas Abiertos de Información Geográfica, S.L. (SAIG S.L.)
Tlfno. móvil: 685005960
Tlfno. fijo: (+34) 954788876

E-mail: [hidden email]


_______________________________________________
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[hidden email]
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