UK OS MasterMap Topography Layer (GML) Reader Parameters

The parameter defaults to http://www.ordnancesurvey.co.uk/xml/namespaces/osgb. This is the XML Namespace URI for the AIXM v5.1. The AIXM version will be used if the dataset contains no xsi:schemaLocation or if the user has the Ignore xsi:schemaLocation in Dataset parameter set.

The default is an alternative way to tell the reader, without having to explicitly specify the file path, that the OS MasterMap GML schema should be used.

An explicit path to the GML schema can be specified by setting the value of this parameter to Other and by using the Application Schema parameter.

When reading schema features or importing feature type definitions into the AIXM5 writer, the reader dataset parameter may be left unset.

A GML instance document specifies the namespace and the location of its application schema through its root element xsi:schemaLocation attribute. This field allows the GML (or GML-based) reader to use a different GML schema document from the one specified in the xsi:schemaLocation attribute.

The XML Schema specification states that the xsi:schemaLocation attribute value consists of a set of pairs: The first member of each pair is the namespace for which the second member is the hint describing where to find an appropriate schema document. The presence of this hint does not require the processor to obtain or use the cited schema document, however, the processor is free to use other schemas obtained by other suitable means.

Determines whether the reader should validate the specified dataset file.

Specifies how the reader obtains feature types:

• XSD Schema – FME reads feature types from the XSD.
• Dataset Only – FME reads feature types from the dataset.
• Dataset Only with Attributes Merged from XSD – FME reads feature types from the dataset, and includes any attributes in the XSD that are associated with a particular feature type.

This parameter can be used to tell the reader to ignore the schema files that are specified in the xsi:schemaLocation attribute of the root element in the dataset. This is particularly useful if the file locations specified in xsi:schemaLocation are not valid file paths.

This parameter instructs the reader to map FeatureCollection as an FME feature.

Values

• gml:FeatureCollection
• wfs:FeatureCollection

Usually, only one value is used within a dataset. Selecting both gml:FeatureCollection and wfs:FeatureCollection may cause a clash in feature type names when both GML and WFS schemas are loaded, since FME needs the feature type to be unique in a reader or writer.

If both values are required, you may need to set the Add XML Namespace Prefix to parameter to a value of Feature Types – this parameter adds the namespace prefix to the feature types to make them unique.

Specifies whether the default and optional GML feature properties, name and description, should be read.

This parameter controls whether XML Namespace prefixes are applied to feature types, attributes, or both. The prefix will be separated from the names by an underscore.

• Feature Types – Includes the prefixes in the feature types. Setting this parameter to Feature Types is necessary if the XSD Schemas contains feature types with the same name in different namespaces.
• Feature Types (On Conflict) – Includes the prefixes in feature types only when the XSD Schemas contain feature types with the same name in different namespaces.
• Feature Types and Attributes – Includes the prefixes in both the feature types and attributes.

The list of whitespace-separated QNames specified in this parameter defines properties that the reader should ignore while processing the GML application schemas.

To ignore property regardless of namespace, simply specify the local-part of the name. For example:

boundedBy name

will ignore all properties whose local name are boundedBy or name, regardless of their namespace.

A prefix in a QName should be present in the parsed XML schemas. If no corresponding URI namespace can be found for a prefix, then the prefix will be discarded. The QName will (as in the unprefixed case) apply to all properties with the same local-part, regardless of namespace.

For example:

gml:boundedBy identifier wrong-prefix:description

If a binding for the gml prefix can be found in the parsed schema, then only boundedBy properties with the same namespace URI as gml will be ignored; otherwise, every boundedBy property regardless of namespace will be ignored.

Every identifier property, regardless of namespace, will be ignored. Every description property regardless of namespace will also be ignored, since the parsed schema will not have a binding for the "wrong-prefix" prefix.

Specifies whether GML properties that are defined as a complex type with complex content (that is, those that have embedded child elements) should be expanded into Nested Attributes within FME features, or stored as XML Fragments.

• If set to XML Fragments, complex properties are not expanded. Instead, their entire content is stored as XML text within a single attribute. This produces smaller, simpler feature structures and is suitable when detailed access to individual child elements is not needed.
• If set to Nested Attributes, complex properties are expanded into nested list attributes wherever possible, exposing their child elements directly as FME attributes. This option is useful when detailed access to individual elements or values is required for mapping or transformation, although it can produce large or deeply nested attribute structures.

When using Nested Attributes, some complex properties that contain embedded objects or geometry elements may still be stored as XML fragments, depending on schema structure or other mapping limits.

Certain complex properties, such as those that are recursively defined or that would otherwise cause circular references, are always mapped as XML fragments regardless of this setting.

This optional parameter applies only when Map Complex Properties As is set to Nested Attributes. It limits how many consecutive levels of multivalued nested list attributes (for example, lists within lists) are preserved before deeper levels are converted into XML fragments.

When the nesting of list elements exceeds this number, expansion automatically stops at that level and deeper content is stored as XML fragments. This helps prevent extremely deep or repetitive data hierarchies from consuming excessive memory or producing unwieldy nested attribute structures.

If this parameter is not specified, all levels of nested lists are expanded up to the general safety limits. Setting a lower value restricts expansion to shallower lists, while a higher value allows deeper nesting at the cost of larger, more complex features.

When this parameter is checked, the reader, in addition to mapping the GML geometry XML elements into FME geometries, will include these elements in FME attributes as XML fragments in the feature.

The FME geometry attributes are typed as xml_geometry in the feature type definition. For applicable GML formats, see the parameter Use Old Reader for GML v3.1.1 and v2.1.2 Documents In the group Version and XML Namespace Processing, which instructs the reader to use the older GML v3.1.1 code base to read GML v3.1.1 and v2.1.2 documents.

This parameter is useful in the case of a GML geometry reading error, since the XML fragment representing the GML geometry will also be carried along in the same feature as an attribute.

Specifies whether GML properties that are mapped as XML fragments should be converted into XML documents.

The conversion will add missing namespace declarations to the fragments, it will maintain CDATA sections, and it will also prefix an XML header declaration to the fragment. Converting the XML fragments into XML documents allows XML-based parsers (for example, XSLT and XQuery-based processors) to further process the fragments.

This parameter specifies whether GML properties that are mapped as XML fragments should be flattened into nested attributes.

The flattening will only be applied to the data features carrying the XML fragments, hence the new flattened nested attributes will not be reflected in the FME feature type schema definitions.

These options are available for the flattened list attributes:

• Substitute Open List Brace – This option specifies the character to use as the open brace for the flattened list attributes. The open brace defaults to a curly brace { but any single character is accepted.
• Substitute Close List Brace – This option specifies the character to use as the close brace for the flattened list attributes. The close brace defaults to a curly brace } but any single character is accepted.
• Substitute Element List Separator – This option specifies the string to use as the separator for components within the nested attributes. The nested attribute component separator defaults to a period (.) but any single character is accepted.

When checked, this parameter instructs the GML reader to use the older GML v3.1.1 code base to read GML v3.1.1 and v2.1.2 documents.

When checked, this parameter disables automatic reader selection/switching.

When checked, this parameter disables XML Namespace processing for the underlying XML parser.

Allows the reader to extract values from the XML schemas. A dataset is not required in this mode since the values for the data features are determined from the XSDs. The XSD value attribute names will be suffixed with .xsd.XXX, where XXX represents various XSD components. A single data feature is constructed for each Explore XSD Values feature type definition.

For example, the "Bygning" SOSI feature type has a "medium" attribute whose type is xml_buffer. The "medium" is an enumeration in the XML schema, but since this is not representable in the FME feature type definitions, xml_buffer was used. Enabling this Explore XSD Values option instructs the reader to construct the following attributes for "medium":

"medium.xsd.enum{}.value" "xml_buffer"
"medium.xsd.enum_values_csv" "xml_buffer"
"medium.xsd.enum{}.annotation.appinfo{}.source" "xml_buffer"
"medium.xsd.enum{}.annotation.appinfo{}.xml_fragment" "xml_xml"
"medium.xsd.enum{}.annotation.documentation{}.source" "xml_buffer"
"medium.xsd.enum{}.annotation.documentation{}.text" "xml_buffer"
"medium.xsd.enum{}.annotation.documentation{}.xml_fragment" "xml_xml"
"medium.xsd.enum{}.annotation.documentation{}.xml_lang" "xml_buffer"

The xsd.enum{} is a list attribute whose component lists a single enumeration value, while xsdl.enum_values_csv is a single attribute listing all enumeration values as a comma-separated string:

"medium.xsd.enum{0}.value" has value "V"
"medium.xsd.enum{1}.value" has value "B"
"medium.xsd.enum{2}.value" has value "L"
"medium.xsd.enum{3}.value" has value "I"
"medium.xsd.enum{4}.value" has value "S"
"medium.xsd.enum{5}.value" has value "T"
"medium.xsd.enum{6}.value" has value "O"
"medium.xsd.enum{7}.value" has value "D"
"medium.xsd.enum{8}.value" has value "J"
"medium.xsd.enum{9}.value" has value "W"
"medium.xsd.enum{10}.value" has value "U"
"medium.xsd.enum{11}.value" has value "X"
"medium.xsd.enum_values_csv" has value "V,B,L,I,S,T,O,D,J,W,U,X"

An enumeration may contain up to a single annotation, while each annotation may contain any number of documentation and appinfo tags. In the same example, the medium.xsd.enum{}.annotation.appinfo{} list attribute component lists the source xml attribute and appinfo content, where appinfo content is an xml fragment. Similarily, the medium.xsd.enum{}.annotation.documentation{} list attribute component lists the source xml attribute, the xml:lang xml attribute, and documentation content as both raw xml (xml_fragment) and text:

"medium.xsd.enum{0}.annotation.documentation{0}.source' has value `'
"medium.xsd.enum{0}.annotation.documentation{0}.text' has value `Alltid i vann '
"medium.xsd.enum{0}.annotation.documentation{0}.xml_fragment' has value `<documentation xmlns="http://www.w3.org/2001/XMLSchema">Alltid i vann</documentation>'
"medium.xsd.enum{0}.annotation.documentation{0}.xml_lang' has value `'

For documentation content, the xml_fragment attribute contains exactly the xml fragment as in the .xsd, while the text attribute contains only existing raw text and no other xml.

Currently, only enumeration values and annotations contained within enumerations are supported.

Use this parameter to expose Format Attributes in FME Workbench when you create a workspace:

• In a dynamic scenario, it means these attributes can be passed to the output dataset at runtime.
• In a non-dynamic scenario, this parameter allows you to expose additional attributes on multiple feature types. Click the browse button to view the available format attributes (which are different for each format) for the reader.

Coordinate systems may be extracted from input feature data sources, may come predefined with FME, or may be user-defined. FME allows different output and input coordinate systems, and performs the required coordinate conversions when necessary.

For systems that know their coordinate system, the Coordinate System field will display Read from Source and FME will read the coordinate system from the source dataset. For most other input sources, the field will display Unknown (which simply means that FME will use default values). In most cases, the default value is all you'll need to perform the translation.

You can always choose to override the defaults and choose a new coordinate system. Select More Coordinate Systems from the drop-down menu to open the Coordinate System Gallery.

Changing a Reprojection

To perform a reprojection, FME typically uses the CS-MAP reprojection engine, which includes definitions for thousands of coordinate systems, with a large variety of projections, datums, ellipsoids, and units. However, GIS applications have slightly different algorithms for reprojecting data between different coordinate systems. To ensure that the data FME writes matches exactly to your existing data, you can use the reprojection engine from a different application.

To change the reprojection engine, Select Workspace Parameters > Spatial > Reprojection Engine. In the example shown, you can select Esri (but the selection here depends on your installed applications):

Specifies whether the GML geometric properties should be represented as attributes in the FME feature type definitions.

In FME data features, the GML geometric properties are represented as a single named geometry – or, if multiple geometries are present, as an aggregate geometry with multiple named geometry components. The name and the position for these geometric elements can also be controlled through the OGC GML User Attributes

• If this parameter is checked (which is the default), then the feature type definitions will contain the geometry names as attributes, and their type is set to xml_geometry. If an attribute X has its type set to xml_geometry, this attribute X becomes a placeholder in the feature type definition. It is a placeholder because actual data features for the feature type definitions will not have this attribute; instead, the data features will have a geometry named “X”.
• If this parameter is unchecked, then the feature type definition will not contain geometry names.

Overrides the axis order when reading a coordinate tuple in a GML element.

Valid values for this parameter:

• 1,2
• 2,1
• 1,2,3
• 2,1,3

There is no default value for most GML formats; however, for IndoorGML, there is a default blank value (which is the same as 1,2,3).

For WFS 1.0, the value is assumed to be 1,2. For WFS 1.1.0 and 2.0.0, the SRS order is determined by the SRS specified. For example, the default axis order for EPSG:4326 is 2,1.

If the srsName in the GML document is set to urn:ogc:def:crs:EPSG:6.6.4326, and you know that the coordinate order in the GML document is lon-lat and not lat-lon order, set this parameter to 1,2 so that the reader reads the data in lon-lat order.

This parameter affects the interpretation of the start and end angles for gml:ArcByCenterPoint.

The parameter overrides the default interpretation for the 0 axis location and angle direction regardless of the dataset SRS.

By default, if the SRS axis order is 1,2 or 1,2,3, then the angle direction is assumed to run counterclockwise starting from the horizontal axis. Otherwise, when the x and y axes are flipped, the angles run clockwise starting from the vertical axis.

This parameter controls how segments in a path are joined together when the segments' end points are not connected:

• Inserting New Line connects the path by inserting a new connecting line between the original segments.
• Snapping End Points forces the first point of each segment to equal the last point of the previous segment.

A search envelope (also known as a bounding box) is a rectangular area that defines a geographic area. In FME, the easiest way to define a search envelope is to use search envelope parameters.

Defining a search envelope is the most efficient method of selecting an area of interest because FME will read only the data that is necessary – it does not have to read an entire dataset. Search Envelope parameters apply to both vector and raster datasets and can be particularly efficient if the source format has a spatial index.

Most FME readers have parameters to define the search envelope of data that is being read:

The parameters include the x and y coordinates of the bounding box as well as a parameter that defines the coordinate system.

How to Define the Bounding Box

Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that intersect with the bounding box are returned. Note that the bounding box intersection is not a full geometry intersection (based on spatial relationships) that would be returned by a transformer like the SpatialFilter.

Authentication Method

Specify the authentication method to use when accessing a password-protected server.

• Basic (default) – Basic access authentication is designed to allow a client to provide credentials to a server on the assumption that the connection between them is trusted and secure. Note that any credentials passed from client to server can be easily intercepted through an insecure connection.
• Digest – Digest authentication is one of the agreed-upon methods a web server can use to negotiate credentials, such as username or password, with a user's web browser.
• NTLM – A challenge-response protocol that is used to provide compatibility with versions of Windows earlier than the Windows 2000 operating systems.
• Web Connection – Web connections provide a convenient and secure way to store and reuse previously established connection parameters. See Web Connection below.
• Single Sign-on – FME will use the credentials of the current user to authenticate the HTTP request. This authentication method currently works only on the Windows operating system.

Web Connection

Using Web Connections

FME Options: Web Connections