Qualifiers
Qualifiers enable meta-data to be associated with modeled elements, and can provide additional information about the element such as a human readable description for a structure or property, or if a particular property is readable or writable.
[Description("example of a structure"), Version("0.0.1")]
Structure schema_structureName {
[Description("String valued property"), Write(true)]
String pname = "pValue";
Sint32 [] ivector = {2, 4, 3};
Boolean bName;
};Qualifiers precede the model element associated with them, and are indicated by a comma separated list enclosed by square brackets. Each qualifier starts with a name, followed by a value enclosed in parenthesis (for non-array values) or by curly braces (for array valued qualifiers). For a particular model element, the value of the qualifier is determined as follows:
- If the qualifier is set on that element, it has the value specified.
- If the qualifier policy is not restricted, and the qualifier has been set on one or more model elements closer to the root of its propagation graph, then the qualifier has the value specified closest to the element.
- If the qualifier has a default value when defined, it takes that value.
- Else it has no value (i.e., the qualifier is null).
Each qualifier has a scope that defines the type of
element (e.g., property or class) it can apply to, a propagation
policy that defines how it is propagated across elements
within an inheritance hierarchy, and a data type that
defines the type of value it can take along with an optional default
value. For Boolean-valued qualifiers, the presence of a
qualifier without a value implies that its value is true, i.e., Write(true)
and Write both imply that the value of the qualifier
Write is true.
A qualifier scope can be one of the following:
| Scope | Description |
|---|---|
| Enumeration | The qualifier applies to Enumerations. |
| Structure | The qualifier applies to Structures. |
| Class | The qualifier applies to Classes. |
| Association | The qualifier applies to Association classes. Note that Fusion does not distinguish between normal classes and association classes, but allows definitions as associations to enable interoperability with DMTF defined specifications. |
| Interface | The qualifier applies to Interface definitions. |
| Method | The qualifier applies to method definitions. |
| Parameter | The qualifier applies to method parameter definitions. |
| Property | The qualifier applies to properties. |
| Reference | The qualifier applies to reference properties. |
| Any | The qualifier applies to any model element that can support qualifiers. |
A qualifier Policy can be of the following types:
| Policy | Description |
|---|---|
| Restricted | A restricted qualifier applies only to the element it applies to, but does not propagate further to sub types of the element it is defined on. |
| DisableOverride | The qualifier propagates to sub types, but cannot be overridden to take a new value by sub types. |
| EnableOverride | The qualifier propagates to sub types, and can be
overridden to take a new value further down the propagation
graph. If no policy is declared on a qualifier (i.e., the
policy value is null), it is assumed to have the policy EnableOverride. |
Standard Qualifiers
Certain qualifiers are "standard" (known to Fusion), and do not need to be defined. These include the following:
| Name | Type | Default value | Scope | Policy |
|---|---|---|---|---|
| Abstract | Boolean | false | CLASS,ASSOCIATION,STRUCTURE | Restricted |
| AggregationKind | String | None | REFERENCE | DisableOverride |
| ArrayType | String | Bag | PROPERTY,PARAMETER,METHOD,REFERENCE | DisableOverride |
| BitMap | String[] | null | METHOD,PROPERTY,PARAMETER | null |
| BitValues | String[] | null | METHOD,PROPERTY,PARAMETER | null |
| Counter | Boolean | false | METHOD,PROPERTY,PARAMETER | DisableOverride |
| Deprecated | String[] | null | ANY | Restricted |
| Description | String | null | ANY | null |
| EmbeddedObject | Boolean | false | METHOD,PROPERTY,PARAMETER | DisableOverride |
| Experimental | Boolean | false | ANY | Restricted |
| Gauge | Boolean | false | METHOD,PROPERTY,PARAMETER | DisableOverride |
| In | Boolean | true | PARAMETER | DisableOverride |
| IsPUnit | Boolean | false | METHOD,PROPERTY,PARAMETER | null |
| Key | Boolean | false | PROPERTY,REFERENCE | DisableOverride |
| MappingStrings | String[] | null | ANY | null |
| Max | UInt32 | null | REFERENCE | null |
| Min | UInt32 | 0 | REFERENCE | null |
| ModelCorrespondence | String[] | null | ANY | null |
| OCL | String[] | null | CLASS,ASSOCIATION,STRUCTURE,INTERFACE,PROPERTY,METHOD,PARAMETER | null |
| Out | Boolean | false | PARAMETER | DisableOverride |
| Override | Boolean | false | METHOD,PROPERTY,REFERENCE,PARAMETER | Restricted |
| PackagePath | String | null | CLASS,ENUMERATION,STRUCTURE,INTERFACE | null |
| PUnit | String | null | METHOD,PROPERTY,PARAMETER | null |
| Read | Boolean | true | PROPERTY,REFERENCE | null |
| Required | Boolean | false | METHOD,PROPERTY,REFERENCE,PARAMETER | DisableOverride |
| Static | Boolean | false | METHOD,PROPERTY,REFERENCE | DisableOverride |
| Terminal | Boolean | false | CLASS,ENUMERATION,STRUCTURE | null |
| Version | String | null | INTERFACE,CLASS,ASSOCIATION,ENUMERATION,STRUCTURE | Restricted |
| Write | Boolean | false | PROPERTY,REFERENCE | null |
| XMLNamespaceName | String | null | PARAMETER,PROPERTY,REFERENCE,METHOD | null |
| Implements | String[] | null | CLASS,STRUCTURE | Restricted |
Abstract
If the value of an Abstract qualifier is true, the qualified association, class, or structure is abstract and serves only as a base. It is not possible to create instances of abstract associations or classes, to define values of abstract structures, or to use abstract types as a type of a typed element (except for reference types). Interface classes are implicitly abstract.
AggregationKind
The AggregationKind qualifier applies to binary associations on a
reference property. The value of AggregationKind qualifier
indicates the type of the aggregation relationship. A value of none
(default) indicates that the relationship is not an
aggregation. Alternatively the value can be sharedto
indicate a shared aggregation or composite to
indicate a composition.
ArrayType
The value of an ArrayType qualifier specifies that the qualified property, reference, parameter, or method return is an array of the specified type. The following types are understood:
| Value | Description |
|---|---|
| bag | The set of element values may contain duplicates, the order of elements is not preserved, and elements may be removed or added. |
| set | The set of element values shall not contain duplicates, the order of elements is not preserved, and elements may be removed or added. |
| ordered | The set of element values may contain duplicates and elements may be removed or added. Except on element addition, removal, or on element value change, the order of elements is preserved. |
| orderedSet | The set of element values shall not contain duplicates and elements may be removed or added. The order of elements is preserved, except on element addition, removal, or on element value change. |
| indexed | The set of element values may contain duplicates, the order of elements is preserved, and individual elements shall not be removed or added. |
Note: The Fusion core model ignores this qualifier, and all treats all arrays as being indexed.
BitMap
This qualifier specifies a set of bit positions that are significant within a method return, parameter or property having an unsigned integer type. Bits are labeled by positions, with the least significant bit having a position of zero (0) and the most significant bit having the position of M, where M is one (1) less than the size of the unsigned integer type. For instance, for a integer constrained to 16 bits, M is 15. The values of the array are unsigned integer bit positions, each represented as a string. The position of a specific value in the Bitmap array defines an index used to select a string literal from the BitValues array.
BitValues
This qualifier specifies a set of literals that corresponds to the respective bit positions specified in a corresponding BitMap qualifier type. The position of a specific value in the Bitmap array defines an index used to select a string literal from the BitValues array.
Counter
If specified as true, the Counter qualifier asserts that the qualified element represents a counter. The type of the qualified element should be an unsigned integer with values that monotonically increase until the value reaches a constraint limit or until the maximum value of the corresponding integer. At that point, counter overflows to its minimum constrained value or zero (0), whichever is greater, and starts monotonically increasing again.
Deprecated
This qualifier indicates that the qualified element has been deprecated, and may be removed in the next major version of the schema following the deprecation. If values are provided, they represent elements that replace the deprecated element.
Description
This qualifier provides a human-readable description of the qualified element.
EmbeddedObject
If specified, the corresponding element contains an encoding of an instance value or an encoding of a class definition.
Experimental
When true, this qualifier specifies that the qualified element is 'experimental' and is under development. The implications of experimental status are specified by the organization that owns the element. If false, the qualified element has 'final' status. Elements with 'final' status should not be modified in backwards incompatible ways within a major schema version. Elements with 'experimental' status may be modified in backwards incompatible ways in any schema version, including within a major schema version.
When an enumeration, structure, class, or association is Experimental, its properties, methods, literals, and local types also have 'experimental' status. However, when an enumeration, structure, class, or association has 'final' status, its properties, methods, literals, and local types may individually have the Experimental qualifier applied with a value of true. Experimental elements for which a decision is made to not take them final should be removed from their schema.
Gauge
If true, the qualified integer element represents a gauge. The type of the qualified element should be an integer with values that can increase or decrease. The value is qualified to be within the range of the elements type and within the range of specified by any applied OCL constraints.
In
This qualifier indicates that the corresponding parameter represents an input value for the method within which the parameter is declared.
Note: All parameters in Fusion are treated as input
parameters. This qualifier is only present for compatibility with
DMTF specifications.
IsPUnit
If the value is true, this qualifier asserts that the value of
the qualified string element represents a programmatic unit of
measure. The value of the string element follows the syntax for
programmatic units, as defined in ANNEX D of the DMTF CIM
Metamodel Version 3 specification.
Key
The Key qualifier asserts that the qualified property or
reference is a key property. In the scope in which it is
instantiated, a separately addressable instance of a class or
value of a structure is identified by its class or structure
name and the name value pairs of all key properties. The
values of key properties and key references are determined once at
instance or value creation time and should not be modified
afterwards. Properties of an array type, properties qualified with
EmbeddedObject or EmbeddedInstance should not be qualified with
Key. Key properties and Key references should not be Null.
MappingStrings
This qualifier takes array values, each of which represents a
corresponding element specified in another standard. Appendix F of
the DMTF CIM specification specifies the mapping format. Within
Fusion, the form Bind.CF|class_name is used to
indicate that class_name represents a java class
that implements the corresponding element for reference
properties.
Max
The value of the Max qualifier specifies the maximum cardinality associated with a reference. If not specified, the cardinality is assumed unbounded.
Min
The value of the Min qualifier specifies the minimum cardinality associated with a reference. If not specified, the minimum cardinality is assumed to be zero.
ModelCorrespondence
The value of the ModelCorrespondence qualifier specifies that the
qualified element is related to another element within the schema.
The nature of the relationship is assumed to be described in the
documentation provided by the organization defining the schema.
OCL
Values of the OCL qualifier specify OCL statements on the
qualified element. Each OCL qualifier has zero (0) or more literal
strings that each hold the value of one OCL statement. The context
(i.e., self) of a specified OCL statement is the qualified
element. All names used in an OCL statement are local to that
element.
Out
This qualifier indicates that the corresponding parameter is an output parameter for a method.
Note: Fusion does not support output parameters.
This qualifier is used only for compatibility with DMTF
specifications. The Fusion metamodel allows methods to
return structure values, which should be used to return multiple
values from methods.
Override
If the value of an Override qualifier is true, the qualified
element is merged with the inherited element of the same name in
the ancestry of the containing type (association, class, or
structure), and replaces the inherited element. The ancestry of an
element is the set of elements that results from recursively
determining its ancestor elements. The merged element is inherited
by sub types of the type that contains the qualified element.
PackagePath
A package is a logical grouping of class, association, structure,
enumeration, and package elements. All elements within a package
are required to have unique names. Packages may be nested and are
used to organize elements of a model as defined in UML (see the
Unified Modeling Language: Superstructure specification). The
value of this qualifier specifies a schema relative name for a
package. If a value is not specified, or is specified as Null, the
package path is assumed to be the schema name of the qualified
element, followed by "::default".
PUnit
If the value of this qualifier is not Null, the value of the
qualified numeric element is in the specified programmatic unit of
measure.
Read
If the value of this qualifier is true, the qualified property
can be read.
Required
If the value of a Required qualifier is true then the qualified
property or reference is required to have a value specified for
it. Note that the specified value can be null, but cannot be left
unspecified (i.e., the property cannot have no value).
Static
This qualifier specifies that the corresponding method or
property is static. A static property or method is not
instance-specific and extends across all instances within some
execution environment.
Terminal
If present, this qualifier specifies that the corresponding
element cannot be further sub typed.
Version
The value of this qualifier specifies the version of the qualified element. The version increments when changes are made to the element. The string representing the version comprises three decimal integers separated by periods; that is, Major.Minor.Update.
Note: A version change applies only to elements that are local to the class. In other words, the version change of a superclass does not require the version in the subclass to be updated.
Write
If the value of this qualifier is true, the qualified property
can be written.
XMLNamespaceName
If the value of this qualifier is not Null, then the value shall
identify an XML schema and this qualifier asserts that values of
the qualified element conforms to the specified XML schema.
Implements
This qualifier lists one or more interface classes (or
structures) that are implemented by the qualified class (or
structure).