gisserver.parsers.wfs20 package¶

WFS 2.0 element parsing.

These classes parse the XML request body.

The full spec can be found at: https://www.ogc.org/publications/standard/wfs/. Secondly, using https://www.mediamaps.ch/ogc/schemas-xsdoc/sld/1.2/wfs_xsd.html can be very helpful to see which options each object type should support.

class gisserver.parsers.wfs20.AdhocQuery(typeNames: list[str], aliases: list[str] | None = None, handle: str = '', srsName: CRS | None = None, property_names: list[PropertyName] | None = None, filter: Filter | None = None, sortBy: SortBy | None = None)¶

Bases: QueryExpression

The Ad hoc query expression parameters.

This parses and handles the syntax:

<wfs:Query typeNames="...">
    <wfs:PropertyName>...</wfs:PropertyName>
    <fes:Filter>...</fes:Filter>
    <fes:SortBy>...</fes:SortBy>
</wfs:Query>

And supports the KVP syntax:

?SERVICE=WFS&...&TYPENAMES=ns:myType&FILTER=...&SORTBY=...&SRSNAME=...&PROPERTYNAME=...
?SERVICE=WFS&...&TYPENAMES=ns:myType&BBOX=...&SORTBY=...&SRSNAME=...&PROPERTYNAME=...
?SERVICE=WFS&...&TYPENAMES=ns:myType&RESOURCEID=...

This represents all dynamic queries received as request (hence “adhoc”), such as the “FILTER” and “BBOX” arguments from an HTTP GET.

The WFS Spec has 3 class levels for this:

AdhocQueryExpression (types, projection, selection, sorting)

Query (adds srsName, featureVersion)

StoredQuery (adds storedQueryID)

For KVP requests, this class seems almost identifical to the provided parameters. However, the KVP format allows to provide parameter lists, to perform support multiple queries in a single request!

__init__(typeNames: list[str], aliases: list[str] | None = None, handle: str = '', srsName: CRS | None = None, property_names: list[PropertyName] | None = None, filter: Filter | None = None, sortBy: SortBy | None = None) → None¶

aliases: list[str] | None = None¶: Aliases for typeNames are used for joining the same table twice. (JOIN statements are not supported yet).

as_kvp() → dict¶: Translate the POST request into KVP GET parameters. This is needed for pagination.

bind(*args, **kwargs)¶: Override to make sure the ‘locator’ points to the actual object that defined the type.

build_query(compiler: CompiledQuery) → Q | None¶: Apply our collected filter data to the compiler.

filter: Filter | None = None¶: Selection clause (implements fes:AbstractSelectionClause). - for XML POST this is encoded in a <fes:Filter> tag. - for HTTP GET, this is encoded as FILTER, FILTER_LANGUAGE, RESOURCEID, BBOX.

classmethod from_kvp_request(kvp: KVPRequest)¶

Build this object from an HTTP GET (key-value-pair) request.

Note the caller should have split the KVP request parameter lists. This class only handles a single parameter pair.

classmethod from_xml(element: NSElement) → AdhocQuery¶: Parse the XML element of the Query tag.

get_projection() → FeatureProjection¶: Tell how the <wfs:Query> element should be displayed.

get_type_names() → list[str]¶: Tell which type names this query uses. Multiple values means a JOIN is made (not supported yet).

handle: str = ''¶: For XML POST requests, this handle value is returned in the <ows:Exception>.

property_names: list[PropertyName] | None = None¶: Projection clause (implements fes:AbstractProjectionClause)

property query_locator¶: Overrides the ‘query_locator’ attribute, so the ‘locator’ argument is correctly set.

sortBy: SortBy | None = None¶: Sorting Clause (implements fes:AbstractSortingClause)

srsName: CRS | None = None¶: The Coordinate Reference System to render the tag in

typeNames: list[str]¶: The ‘typeNames’ value if the request provided them. use get_type_names() instead.

class gisserver.parsers.wfs20.DescribeFeatureType(service: str, version: str | None, handle: str | None, typeNames: list[str] | None = None, outputFormat: str | None = 'XMLSCHEMA')¶

Bases: BaseOwsRequest

The <wfs:DescribeFeatureType> element.

This parses the syntax:

<wfs:DescribeFeatureType version="2.0.0" service="WFS">
  <wfs:TypeName>ns01:TreesA_1M</wfs:TypeName>
  <wfs:TypeName>ns02:RoadL_1M</wfs:TypeName>
</wfs:DescribeFeatureType>

And supports the GET syntax as well:

?SERVICE=WFS&VERSION=2.0.0&REQUEST=DescribeFeatureType&TYPENAMES=ns01:TreesA_1M,ns02:RoadL_1M

__init__(service: str, version: str | None, handle: str | None, typeNames: list[str] | None = None, outputFormat: str | None = 'XMLSCHEMA') → None¶

classmethod from_kvp_request(kvp: KVPRequest)¶: Parse the KVP GET request

classmethod from_xml(element: NSElement)¶: Parse the XML POST request.

outputFormat: str | None = 'XMLSCHEMA'¶

typeNames: list[str] | None = None¶

class gisserver.parsers.wfs20.DescribeStoredQueries(service: str, version: str | None, handle: str | None, storedQueryId: list[str] | None = None)¶

Bases: BaseOwsRequest

The <wfs:DescribeStoredQueries> element.

This parses the syntax:

<wfs:DescribeStoredQueries>
  <wfs:StoredQueryId>...</wfs:StoredQueryId>
  <wfs:StoredQueryId>...</wfs:StoredQueryId>
</wfs:DescribeStoredQueries>

And the KVP syntax:

?REQUEST=DescribeStoredQueries&STOREDQUERY_ID=...,...

__init__(service: str, version: str | None, handle: str | None, storedQueryId: list[str] | None = None) → None¶

classmethod from_kvp_request(kvp: KVPRequest)¶: Parse the KVP GET request.

classmethod from_xml(element: NSElement)¶: Parse the XML POST request.

storedQueryId: list[str] | None = None¶

Bases: BaseOwsRequest

Request parsing for GetCapabilities.

This parses and handles the syntax:

<wfs:GetCapabilities service="WFS" updateSequence="" version="">
    <ows:AcceptVersions>
        <ows:Version>...</ows:Version>
    </ows:AcceptVersions>
    <ows:Sections>
        <ows:Section>...</ows:Section>
        <ows:Section>...</ows:Section>
    </ows:Sections>
    <ows:AcceptFormats>
        <ows:OutputFormat>...</ows:OutputFormat>
        <ows:OutputFormat>...</ows:OutputFormat>
    </ows:AcceptFormats>
    <ows:AcceptLanguages>
        <ows:Language>...</ows:Language>
        <ows:Language>...</ows:Language>
    </ows:AcceptLanguages>
</wfs:GetCapabilities>

And supports the GET syntax as well:

?SERVICE=WFS&REQUEST=GetCapabilities&ACCEPTVERSIONS=2.0.0,1.1.0

__init__(service: str, version: str | None, handle: str | None, updateSequence: str | None = None, acceptVersions: list[str] | None = None, sections: list[str] | None = None, acceptFormats: list[str] | None = None, acceptLanguages: list[str] | None = None) → None¶

acceptFormats: list[str] | None = None¶

acceptLanguages: list[str] | None = None¶

acceptVersions: list[str] | None = None¶

classmethod from_kvp_request(kvp: KVPRequest)¶: Parse the KVP request format.

classmethod from_xml(element: NSElement)¶: Parse the XML tag for the GetCapabilities.

sections: list[str] | None = None¶

updateSequence: str | None = None¶

class gisserver.parsers.wfs20.GetFeature(service: str, version: str | None, handle: str | None, queries: list[QueryExpression] = None, resolve: ResolveValue = ResolveValue.none, resolveDepth: int | None = None, resolveTimeout: int = 300, count: int | None = None, outputFormat: str = 'application/gml+xml; version=3.2', resultType: ResultType = ResultType.results, startIndex: int = 0)¶

Bases: StandardPresentationParameters, StandardResolveParameters, CommonQueryParameters, BaseOwsRequest

The <wfs:GetFeature> element.

This parses the syntax:

<wfs:GetFeature outputFormat="application/gml+xml; version=3.2">
   <wfs:Query typeName="myns:InWaterA_1M">
      <fes:Filter>
          ...
      </fes:Filter>
   </wfs:Query>
</wfs:GetFeature>

And supports the KVP syntax:

?SERVICE=WFS&VERSION=2.0.0&REQUEST=GetFeature&TYPENAMES=myns:InWaterA_1M&FILTER=...

__init__(service: str, version: str | None, handle: str | None, queries: list[QueryExpression] = None, resolve: ResolveValue = ResolveValue.none, resolveDepth: int | None = None, resolveTimeout: int = 300, count: int | None = None, outputFormat: str = 'application/gml+xml; version=3.2', resultType: ResultType = ResultType.results, startIndex: int = 0) → None¶

class gisserver.parsers.wfs20.GetPropertyValue(service: str, version: str | None, handle: str | None, queries: list[QueryExpression] = None, resolve: ResolveValue = ResolveValue.none, resolveDepth: int | None = None, resolveTimeout: int = 300, count: int | None = None, outputFormat: str = 'application/gml+xml; version=3.2', resultType: ResultType = ResultType.results, startIndex: int = 0, resolvePath: str | None = None, valueReference: ValueReference = None)¶

Bases: StandardPresentationParameters, StandardResolveParameters, CommonQueryParameters, BaseOwsRequest

The <wfs:GetPropertyValue> element.

This parses the syntax:

<wfs:GetPropertyValue valueReference="...">
   <wfs:Query typeName="myns:InWaterA_1M">
      <fes:Filter>
          ...
      </fes:Filter>
   </wfs:Query>
</wfs:GetFeature>

As this is so similar to the GetFeature syntax, these inherit from each other.

The KVP-syntax is also supported:

?SERVICE=WFS&VERSION=2.0.0&REQUEST=GetPropertyName&...&&VALUEREFERENCE=...

__init__(service: str, version: str | None, handle: str | None, queries: list[QueryExpression] = None, resolve: ResolveValue = ResolveValue.none, resolveDepth: int | None = None, resolveTimeout: int = 300, count: int | None = None, outputFormat: str = 'application/gml+xml; version=3.2', resultType: ResultType = ResultType.results, startIndex: int = 0, resolvePath: str | None = None, valueReference: ValueReference = None) → None¶

as_kvp() → dict¶: Translate the POST request into KVP GET parameters. This is needed for pagination.

classmethod from_kvp_request(kvp: KVPRequest)¶: Parse the KVP GET request.

classmethod from_xml(element: NSElement)¶: Parse the XML POST request.

resolvePath: str | None = None¶

valueReference: ValueReference = None¶

class gisserver.parsers.wfs20.ListStoredQueries(service: str, version: str | None, handle: str | None)¶

Bases: BaseOwsRequest

The <wfs:ListStoredQueries> element.

classmethod from_xml(element: NSElement)¶: Initialize from an XML POST request.

class gisserver.parsers.wfs20.PropertyName(xpath: str, xpath_ns_aliases: dict[str, str], resolve: ResolveValue = ResolveValue.none, resolve_depth: int | None = None, resolve_path: str | None = None, resolve_timeout: int = 300)¶

Bases: AstNode

The <wfs:PropertyName> element in the projection clause.

This parses and handles the syntax:

<wfs:PropertyName>ns0:tagname</wfs:PropertyName>

More advanced syntax is not supported, such as:

<wfs:PropertyName resolve="all" resolvePath="valueOf(relatedTo)">valueOf(registerEntry)</wfs:PropertyName>

Note this element exists in the WFS namespace, not the FES namespace! The <fes:PropertyName> is an old FES 1.x element that has been replaced by <fes:ValueReference>. The old <fes:PropertyName> is still supported as an alias by this server.

__init__(xpath: str, xpath_ns_aliases: dict[str, str], resolve: ResolveValue = ResolveValue.none, resolve_depth: int | None = None, resolve_path: str | None = None, resolve_timeout: int = 300) → None¶

decorate_query(compiler: CompiledQuery)¶: Update the low-level query based on this property projection.

classmethod from_xml(element: NSElement)¶: Parse the XML tag.

parse_xpath(feature_types: list) → XPathMatch¶: Convert the XPath into the required ORM query elements.

resolve: ResolveValue = 'none'¶

resolve_depth: int | None = None¶

resolve_path: str | None = None¶

resolve_timeout: int = 300¶

xpath: str¶

xpath_ns_aliases: dict[str, str]¶

class gisserver.parsers.wfs20.QueryExpression¶

Bases: AstNode

WFS base class for all queries. This object type is defined in the WFS spec (as <fes:AbstractQueryExpression>).

The WFS server can initiate queries in multiple ways. This class provides the common interface for all these query types; whether the request provided “ad-hoc” parameters or called a stored procedure. Each query type has its own way of generating the actual database statement to perform.

The subclasses can override the following logic:

get_type_names() defines which types this query applies to.
build_query() defines how to filter the queryset.

For full control, these methods can also be overwritten instead:

get_queryset() defines the full results.

as_kvp() → dict¶: Translate the POST request into KVP GET parameters. This is needed for pagination.

bind(feature_types: list[FeatureType], value_reference: ValueReference | None = None)¶

Bind the query to context outside its tag definition.

Parameters:

feature_types – The corresponding feature types for get_type_names().
value_reference – Which field is returned (by GetPropertyValue)

build_query(compiler: CompiledQuery) → Q | None¶: Define the compiled query that filters the queryset.

get_projection() → FeatureProjection¶: Tell how the query should be displayed.

get_queryset() → QuerySet¶

Generate the queryset for the specific feature type.

This method can be overwritten in subclasses to define the returned data. However, consider overwriting build_query() instead of simple data.

get_type_names() → list[str]¶

Tell which type names this query applies to. Multiple values means a JOIN is made (not supported yet).

This method needs to be defined in subclasses.

handle: str = ''¶: The ‘handle’ that will be returned in exceptions.

property_names: list[PropertyName] | None = None¶: Projection parameters (overwritten by subclasses) In the WFS spec, this is only part of the operation/presentation. For Django, we’d like to make this part of the query too.

query_locator: ClassVar[str] = None¶: Configuration for the ‘locator’ argument in exceptions

value_reference: ValueReference | None = None¶: The valueReference for the GetPropertyValue call, provided here for extra ORM filtering.

class gisserver.parsers.wfs20.ResultType(*values)¶

Bases: Enum

WFS result type format.

hits = 'HITS'¶

results = 'RESULTS'¶

class gisserver.parsers.wfs20.StoredQuery(id: str, parameters: dict[str, ~typing.Any], ns_aliases: dict[str, str] = <factory>)¶

Bases: QueryExpression

The <wfs:StoredQuery> element.

This loads a predefined query on the server. A good description can be found at: https://mapserver.org/ogc/wfs_server.html#stored-queries-wfs-2-0

This parses the following syntax:

<wfs:StoredQuery handle="" id="">
  <wfs:Parameter name="">...</wfs:Parameter>
  <wfs:Parameter name="">...</wfs:Parameter>
</wfs:StoredQuery>

and the KVP syntax:

?SERVICE=WFS&REQUEST=GetFeature&VERSION=2.0.0&STOREDQUERY_ID=...&{parameter}=...

Note that the base class logic (such as <wfs:PropertyName> elements) are still applicable.

This element resolves the stored query using the StoredQueryRegistry, and passes the execution to this custom function.

__init__(id: str, parameters: dict[str, ~typing.Any], ns_aliases: dict[str, str] = <factory>) → None¶

as_kvp() → dict¶: Translate the POST request into KVP GET parameters. This is needed for pagination.

bind(*args, **kwargs)¶: Associate this query with the application context.

build_query(compiler: CompiledQuery)¶: Forward queryset creation to the implementation class.

finalize_results(result: SimpleFeatureCollection)¶

classmethod from_kvp_request(kvp: KVPRequest)¶: Parse the KVP request syntax. Any query parameters are additional parameters at the query string.

classmethod from_xml(element: NSElement)¶: Read the XML element.

get_projection() → FeatureProjection¶: Tell how the <wfs:StoredQuery> output should be displayed.

get_type_names() → list[str]¶: Tell which features are touched by the query.

id: str¶

property implementation: StoredQueryImplementation¶: Initialize the stored query from this request.

ns_aliases: dict[str, str]¶

parameters: dict[str, Any]¶

query_locator: ClassVar[str] = 'STOREDQUERY_ID'¶: Configuration for the ‘locator’ argument in exceptions

gisserver.parsers.wfs20 package¶

django-gisserver

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