This page gives a few examples of how XML constructs are mapped to OGR layers and fields by the GMLAS driver.
| Schema | Document | OGR layers | Comments |
|---|---|---|---|
<schema xmlns="http://www.w3.org/2001/XMLSchema">
<element name="MyFeature">
<complexType>
<sequence>
<element name="name" type="string"/>
</sequence>
<attribute name="id" type="ID" use="required"/>
<attribute name="attr" type="string"/>
</complexType>
</element>
</schema>
|
<MyFeature id="my_id" attr="attr_value">
<name>my_name</name>
</MyFeature>
|
Layer name: MyFeature Geometry: None id: String (0.0) NOT NULL attr: String (0.0) name: String (0.0) NOT NULL OGRFeature(MyFeature):1 id (String) = my_id attr (String) = attr_value name (String) = my_name |
Element with attributes and sub-elements of simple type and maximum cardinality of 1. |
<schema xmlns="http://www.w3.org/2001/XMLSchema">
<element name="MyFeature">
<complexType>
<sequence>
<element name="str_array" type="string"
maxOccurs="2"/>
<element name="dt_array" type="dateTime"
maxOccurs="unbounded"/>
</sequence>
<attribute name="id" type="ID" use="required"/>
</complexType>
</element>
</schema>
|
<MyFeature id="my_id">
<str_array>first string</str_array>
<str_array>second string</str_array>
<dt_array>2016-09-24T15:31:00Z</dt_array>
<dt_array>2016-09-24T15:32:00Z</dt_array>
</MyFeature>
|
Layer name: MyFeature
Geometry: None
id: String (0.0) NOT NULL
str_array: StringList (0.0) NOT NULL
OGRFeature(MyFeature):1
id (String) = my_id
str_array (StringList) =
(2:first string,second string)
Layer name: MyFeature_dt_array
Geometry: None
ogr_pkid: String (0.0) NOT NULL
parent_id: String (0.0) NOT NULL
value: DateTime (0.0)
OGRFeature(MyFeature_dt_array):1
ogr_pkid (String) = my_id_dt_array_1
parent_id (String) = my_id
value (DateTime) = 2016/09/24 15:31:00+00
OGRFeature(MyFeature_dt_array):2
ogr_pkid (String) = my_id_dt_array_2
parent_id (String) = my_id
value (DateTime) = 2016/09/24 15:32:00+00
|
Case of array and child layer |
<schema xmlns="http://www.w3.org/2001/XMLSchema">
<element name="MyFeature">
<complexType>
<sequence>
<element name="identifier">
<complexType>
<sequence>
<element name="name">
<complexType>
<simpleContent>
<extension base="string">
<attribute name="lang"
type="string"/>
</extension>
</simpleContent>
</complexType>
</element>
<element name="namespace" type="string"
minOccurs="0"/>
</sequence>
</complexType>
</element>
</sequence>
<attribute name="id" type="ID" use="required"/>
</complexType>
</element>
</schema>
|
<MyFeature id="my_id">
<identifier>
<name lang="en">my_name</name>
<namespace>baz</namespace>
</identifier>
</MyFeature>
|
Layer name: MyFeature Geometry: None id: String (0.0) NOT NULL identifier_name_lang: String (0.0) identifier_name: String (0.0) identifier_namespace: String (0.0) OGRFeature(MyFeature):1 id (String) = my_id identifier_name_lang (String) = en identifier_name (String) = my_name identifier_namespace (String) = baz |
Case of nested element, that can be folded into main layer. Use of an attribute on a sub-element. |
<schema xmlns:myns="http://myns"
targetNamespace="http://myns"
elementFormDefault="qualified"
xmlns="http://www.w3.org/2001/XMLSchema">
<element name="AbstractFeature" abstract="true"/>
<element name="FeatureCollection">
<complexType><sequence>
<element ref="myns:AbstractFeature" maxOccurs="unbounded"/>
</sequence></complexType>
</element>
<complexType name="namesType">
<sequence>
<element ref="myns:name" maxOccurs="unbounded"/>
</sequence>
</complexType>
<element name="MyFeature" substitutionGroup="myns:AbstractFeature">
<complexType><sequence>
<element name="names" type="myns:namesType"/>
</sequence>
<attribute name="id" type="ID" use="required"/>
</complexType>
</element>
<element name="MyFeature2" substitutionGroup="myns:AbstractFeature">
<complexType><sequence>
<element name="names" type="myns:namesType"/>
</sequence>
<attribute name="id" type="ID" use="required"/>
</complexType>
</element>
<element name="name">
<complexType><sequence>
<element name="name" type="string"/>
<element name="lang" type="string"/>
</sequence></complexType>
</element>
</schema>
|
<FeatureCollection xmlns="http://myns">
<MyFeature id="my_id">
<names>
<name>
<name>name</name>
<lang>en</lang>
</name>
<name>
<name>nom</name>
<lang>fr</lang>
</name>
</names>
</MyFeature>
<MyFeature2 id="my_id2">
<names>
<name>
<name>nom2</name>
<lang>fr</lang>
</name>
</names>
</MyFeature2>
</FeatureCollection>
|
Layer name: name OGRFeature(name):1 ogr_pkid (String) = _name_1 name (String) = name lang (String) = en OGRFeature(name):2 ogr_pkid (String) = _name_2 name (String) = nom lang (String) = fr OGRFeature(name):3 ogr_pkid (String) = _name_3 name (String) = nom2 lang (String) = fr Layer name: MyFeature OGRFeature(MyFeature):1 id (String) = my_id Layer name: MyFeature2 OGRFeature(MyFeature2):1 id (String) = my_id2 Layer name: MyFeature_names_name_name OGRFeature(MyFeature_names_name_name):1 occurrence (Integer) = 1 parent_pkid (String) = my_id child_pkid (String) = _name_1 OGRFeature(MyFeature_names_name_name):2 occurrence (Integer) = 2 parent_pkid (String) = my_id child_pkid (String) = _name_2 Layer name: MyFeature2_names_name_name OGRFeature(MyFeature2_names_name_name):1 occurrence (Integer) = 1 parent_pkid (String) = my_id2 child_pkid (String) = _name_3 |
Case of a common element "name" referenced by 2 layers "MyFeature" and "MyFeature1". The links are established through the junction layers "MyFeature_names_name_name" and "MyFeature2_names_name_name". |
<swe:DataArray>
<swe:elementCount>
<swe:Count>
<swe:value>2</swe:value>
</swe:Count>
</swe:elementCount>
<swe:elementType name="Components">
<swe:DataRecord>
<swe:field name="myTime">
<swe:Time definition="http://www.opengis.net/def/property/OGC/0/SamplingTime">
<swe:uom xlink:href="http://www.opengis.net/def/uom/ISO-8601/0/Gregorian"/>
</swe:Time>
</swe:field>
<swe:field name="myCategory">
<swe:Category definition="http://dd.eionet.europa.eu/vocabulary/aq/observationverification"/>
</swe:field>
<swe:field name="myQuantity">
<swe:Quantity definition="http://dd.eionet.europa.eu/vocabulary/aq/primaryObservation/hour">
<swe:uom xlink:href="http://dd.eionet.europa.eu/vocabulary/uom/concentration/ug.m-3"/>
</swe:Quantity>
</swe:field>
<swe:field name="myCount">
<swe:Count definition="http://"/>
</swe:field>
<swe:field name="myText">
<swe:Text definition="http://"/>
</swe:field>
<swe:field name="myBoolean">
<swe:Boolean definition="http://"/>
</swe:field>
</swe:DataRecord>
</swe:elementType>
<swe:encoding>
<swe:TextEncoding decimalSeparator="." blockSeparator="@@" tokenSeparator=","/>
</swe:encoding>
<swe:values>2016-09-01T00:00:00+01:00,1,2.34,3,foo,true@@2017-09-01T00:00:00,2,3.45</swe:values>
</swe:DataArray>
will receive a special processing to be mapped into a dedicated layer:
Layer name: dataarray_1_components Geometry: None Feature Count: 2 Layer SRS WKT: (unknown) parent_ogr_pkid: String (0.0) NOT NULL mytime: DateTime (0.0) mycategory: String (0.0) myquantity: Real (0.0) mycount: Integer (0.0) mytext: String (0.0) myboolean: Integer(Boolean) (0.0) OGRFeature(dataarray_1_components):1 parent_ogr_pkid (String) = BAE8440FC4563A80D2AB1860A47AA0A3_DataArray_1 mytime (DateTime) = 2016/09/01 00:00:00+01 mycategory (String) = 1 myquantity (Real) = 2.34 mycount (Integer) = 3 mytext (String) = foo myboolean (Integer(Boolean)) = 1 OGRFeature(dataarray_1_components):2 parent_ogr_pkid (String) = BAE8440FC4563A80D2AB1860A47AA0A3_DataArray_1 mytime (DateTime) = 2017/09/01 00:00:00 mycategory (String) = 2 myquantity (Real) = 3.45