If the linkage is of type string, then these attribute list item names are used to specify the values for the string linkage:
Attribute Lists – string linkage
|
Linkage Parameter |
Contents |
|---|---|
| stringId |
The key or identifier of the string linkage. This is application-specific, but required on write. Range: Unsigned 32-bit integer Default: No default |
| string |
The text data of the string linkage, in system encoding. Range: Any string Default: No default |
XAttribute Attributes
Each element in a Design file may have one or more Xattribute attributes attached to it.
Because an element may have more than one XAttribute, these attributes are stored in an FME feature attribute list named igds_xattributes{#}. As with other feature attribute lists, # starts at zero and increments for each successive linkage.
Attribute Lists – XFM Linkages
XML-based Feature Modelling (XFM) data exists in two known versions in version 8 Design files. Both forms consist of element attributes and potential additional elements which may be referenced to provide additional XFM information or details. Both versions are read with the DGNV8 Reader as attributes on elements and reference elements, which provides a normalized form of XFM features.
This format provides a more XFM-oriented representation of the XFM data. It treats the XFM feature names as the feature types for elements with XFM data. It also merges XFM data from reference elements and flattens any XML fragments into user attributes on the features created by the reader. XFM linkages are the first version are associated with Bentley Map Select Series 1. These linkages exist on elements, and on potential non-geometric reference elements of type igds_xfmstore.
XFM linkages are the first version associated with Bentley Map Select Series 1. These linkages exist on elements, and on potential non-geometric reference elements of type igds_xfmstore.
The primary form of XFM linkages contains Universally Unique Identifier (UUID) values which are used to associate non-graphical XFM feature store elements with other graphical elements, and with each other in a one-to-one relationship.
XFM features may actually be represented by a hierarchy of elements related by XFM XAttributes, and it is the relationship of an element with XFM properties and an associated element that may be a part of this combination of graphics and properties. The focus of the DGNV8 Reader is to read XFM feature stores for the purpose of providing XFM properties with a specific graphical element in an XFM feature hierarchy.
A secondary form of XFM linkage simply stores XFM XML information on an element. Both the primary and secondary normalized forms of XFM data can be read and written with the DGNV8 format.
If the linkage is one of these types, then these attribute list item names are used to specify the values for the linkage:
|
Linkage Parameter |
Contents |
|---|---|
| xfm_data_prefix |
A binary encoded string value for the bytes prefixing the core data of an XFM item for an element. This is application-specific and may be used to construct XFM data for an element when writing. (However, it may be calculated when writing if not supplied.) This attribute has an alias as igds_xfm_data_prefix. Range: Valid 4-byte binary encoded string Default: No default |
| xfm_parent_uuid |
A UUID for the parent XFM feature for this element in a potential XFM feature hierarchy. If this element is the root XFM feature, then this linkage attribute will be a UUID of all zeros. This attribute has an alias as igds_xfm_parent_uuid. Range: Any UUID value in string format Default: UUID of all zeros |
| xfm_root_uuid |
A UUID for the root XFM feature for this element in a potential XFM feature hierarchy. If this element is the root XFM feature, then this linkage attribute will be the same as the xfm_uuid linkage attribute. This attribute has an alias as igds_xfm_root_uuid. Range: Any UUID value in string format Default: The same value as the xfm_uuid attribute |
| xfm_uuid |
A UUID for this XFM feature element, acting as an identifier for referencing XFM data. When writing, this linkage attribute is required to create an XFM UUID linkage. This attribute has an alias as igds_xfm_uuid. Range: Any UUID value in string format Default: No default |
| xml_data_prefix |
A binary encoded string value for the bytes prefixing XML data in a secondary form XFM XML linkage. This is used by the Writer to recreate the same XFM XML linkage read by the Reader, however, this data may be calculated by the writer if not supplied. Range: Valid 32-byte binary encoded string Default: No default |
| xml_data |
A UNICODE (UTF-16) encoded string containing the XML data in a secondary form XFM XML linkage. Range: Any valid XML string Default: No default |
Attribute Lists – XFM XAttributes
XML-based Feature Modelling (XFM) data exists in two known versions in version 8 Design files. Both forms consist of element attributes and potential additional elements which may be referenced to provide additional XFM information or details. Both versions are read with the DGNV8 Reader as attributes on elements and reference elements, which provides a normalized form of XFM features.
Note: This format may be preferable instead of the Bentley MicroStation Design Reader/Writer for a more XFM-oriented representation of the XFM data. The reader treats the XFM feature names as the feature types for elements with XFM data. It also merges XFM data from reference elements and flattens any XML fragments into user attributes on the features created by the reader.
XFM XAttributes are the second version associated with Bentley Map Select Series 3 and newer. These XAttributes exist on elements, and on potential reference elements of type igds_polygon_collection and igds_nongeom_collection. The primary form of XFM XAttributes contains either Universally Unique Identifier (UUID) values or element identifiers which are used to associate non-graphical XFM feature store elements with other graphical elements.
XFM features may actually be represented by a hierarchy of elements related by XFM XAttributes, and it is the relationship of an element with XFM properties and an associated element that may be a part of this combination of graphics and properties. The focus of the DGNV8 Reader is to read XFM feature stores for the purpose of providing XFM properties with a specific graphical element in an XFM feature hierarchy.
If XFM XAttributes exist, then these attribute list item names are used to specify the values for them:
| Linkage Parameter | Contents |
|---|---|
| attr_id | An identifier for the Xattribute. |
| data |
A binary encoded string value for the unknown data associated with uninterpreted Xattribute types. Range: A valid context-specific variable length binary encoded string Default: No default |
| data_prefix |
A binary encoded string value for the bytes prefixing the core data of an XFM item for an element. This is application-specific. This attribute has an alias as igds_xfm_data_prefix. Range: A valid context-specific variable length binary encoded string Default: No default |
| feature |
This attribute is used when reading an XFM feature element or XFM reference element. It indicates the name of the XFM feature. This attribute has an alias as igds_xfm_name. Range: A UNICODE (UTF-16) encoded string Default: No default |
| handler_id |
This is a number representing a sub-type of an XAttribute handler. For each handler_type these are context-specific values further specify what is stored. Range: Any positive integer Default: No default |
| handler_type |
This is a number representing a type of an XAttribute handler. This value is similar to the userId property of User Linkages. Range: Any positive integer Default: No default |
| ref_elem_id |
The identifier of an element for referencing XFM data. Range: Any positive integer Default: No default |
| type |
This is a string representing the general type of an XAttribute. Range: xattr_binary_xml | xattr_proxy | xattr_unknown | xattr_xml etc. Default: xattr_unknown |
| url |
The UNICODE (UTF-16) encoded string for an XFM feature URL fragment. This is typically found on an XFM reference feature. However, it may appear on other features that contain XFM data. Range: Any valid URL String. Default: No default |
| xfm_uuid |
A UUID for this XFM feature element, acting as an identifier for referencing XFM data. This attribute has an alias as igds_xfm_uuid. Range: Any UUID value in string format Default: No default |
| xml |
A UNICODE (UTF-16) encoded string containing the XML data in a secondary form XFM XML linkage. Range: Any valid XML string Default: No default |
XFM Feature Stores
XFM Feature Stores correspond to IGDS element type 39.
These features represent the non-graphic portion of instances of Bentley Map XML-based Feature Modeling (XFM) features, as a part of a representation of Select Series 1 XFM features. See the Bentley Map XFM Design format for an alternative object representation.
They are elements that contain XML strings representing XFM feature properties. They may also contain a set of XFM UUID linkages which consist of Universally Unique Identifiers (UUIDs). These XFM linkages may occur on both XFM feature store elements and on other graphical elements in order to associate these elements with each other.
XFM features may actually be represented by a hierarchy of elements related by XFM linkages, and it is the relationship of an XFM feature store and an associated element that may be a part of this combination of graphics and properties. The focus of the DGNV8XFM Reader is to read XFM feature stores for the purpose of providing XFM properties with a specific graphical element in an XFM feature hierarchy.
XFM feature store elements have an igds_type of igds_xfmstore, and the attributes shown below. As a convenience, if the DGN V8 Writer is given features with an igds_type other than igds_xfmstore which has an igds_xfmstore_xml attribute, an XFM feature store element will be automatically created. Such a feature will also create a graphical element and the XFM linkages required to relate such an element to the new XFM feature store element. Furthermore, the name of XFM feature to create in this case may be specified by the igds_xfm_name attribute.
| Attribute Name | Contents |
|---|---|
| igds_xfmstore_appid_word0 |
The first two bytes of the application identifier for an XFM feature store element. This is not used by the Writer. Range: Valid unsigned 16-bit integer Default: 1 for elements with XFM UUID linkage attributes and 7 for elements without XFM UUID linkage attributes |
| igds_xfmstore_appid_word1 |
The second two bytes of the application identifier for an XFM feature store element. This is not used by the Writer. Range: Valid unsigned 16-bit integer Default: 22564 |
| igds_xfmstore_storeid |
The store identifier string for an XFM feature store element. This is not used by the Writer. Range: Valid store id string Default: XMLf |
| igds_xfmstore_url |
The UNICODE (UTF-16) encoded string for a URL. Potentially points to an XML schema. Range: Any valid URL string Default: No default |
| igds_xfmstore_xml |
The UNICODE (UTF-16) encoded string for an XFM feature store XML fragment. Range: Any valid XML String Default: No default |
Polygon Collections
Polygon Collection features correspond to element type 106, which was added in Bentley Map Select Series 3.
These features represent a logical grouping of area elements. In XFM datasets, they can represent the shared Bentley Map XML-based Feature Modeling (XFM) data of the grouped elements. They are part of the XFM data representation as a normalized representation of XFM features. See the Bentley Map XFM Design format for an alternative object representation.
When these elements are associated with XFM data, they may contain XML XAttributes representing XFM feature properties. They may also contain a set of XFM XAttributes which consist of Universally Unique Identifiers (UUIDs). These XFM XAttributes may occur on both XFM Polygon Collection elements and on other graphical elements in order to associate these elements with each other.
XFM features may actually be represented by a hierarchy of elements related by XFM XAttributes, and it is the relationship of an element with XFM properties, such as a polygon collection, and an associated element that may be a part of this combination of graphics and properties. The focus of the DGNV8 Reader is to read XFM feature stores for the purpose of providing XFM properties with a specific graphical element in an XFM feature hierarchy.
There are no attributes specific to polygon collections. Refer to the XFM XAttributes section for XFM related attributes (which they may have).
Non-Geometric Collections
Non-geometric Collection features correspond to element type 107, which was added in Bentley Map Select Series 3.
These features represent a logical grouping of elements. In XFM datasets, they can represent the shared Bentley Map XML-based Feature Modeling (XFM) data of the grouped elements. They are part of the XFM data representation as a normalized representation of XFM features. See the Bentley Map XFM Design format for an alternative object representation.
When these elements are associated with XFM data, they may contain XML XAttributes representing XFM feature properties. They may also contain a set of XFM linkages which consist of Universally Unique Identifiers (UUIDs). These XFM XAttributes may occur on both XFM Non-geometric Collection elements and on other graphical elements in order to associate these elements with each other.
XFM features may actually be represented by a hierarchy of elements related by XFM XAttributes, and it is the relationship of an element with XFM properties, such as a polygon collection, and an associated element that may be a part of this combination of graphics and properties. The focus of the DGNV8 Reader is to read XFM feature stores for the purpose of providing XFM properties with a specific graphical element in an XFM feature hierarchy.
There are no attributes specific to non-geometric collections. Refer to the XFM XAttributes section for XFM related attributes (which they may have).