any (code generated for the type by an IDL comp
been compiled with the object implementation). As a result, the object receiving the
any does not have a portable method of using it.
-DynAnys enable traversal of the data value associated with an
-any at runtime, and extraction of the primitive constituents of the data value.
-This is especially helpful for writing powerful generic servers (bridges, event channels
-supporting filtering). Similarly, this facility enables the construction of an
-any at runtime, without having static knowledge of its type. This is especially
+
DynAnys enable traversal of the data value associated with an
+any at runtime, and extraction of the primitive constituents of the data value.
+This is especially helpful for writing powerful generic servers (bridges, event channels
+supporting filtering). Similarly, this facility enables the construction of an
+any at runtime, without having static knowledge of its type. This is especially
helpful for writing generic clients (bridges, browsers, debuggers, user interface tools).
-
Any values can be dynamically interpreted (traversed) and constructed through
-DynAny objects. A DynAny object is associated with a data
-value which corresponds to a copy of the value inserted into an Any. A
+
Any values can be dynamically interpreted (traversed) and constructed through
+DynAny objects. A DynAny object is associated with a data
+value which corresponds to a copy of the value inserted into an Any. A
DynAny object may be viewed as an ordered collection of component
-DynAnys. For DynAnys representing a basic type, such as long,
-or a type without components, such as an empty exception, the ordered collection of
-components is empty.
+DynAnys. For DynAnys representing a basic type, such as long,
+or a type without components, such as an empty exception, the ordered collection of
+components is empty.
-
Each DynAny object maintains the notion of a current position into its collection -of component DynAnys. The current position is identified by an index value that runs -from 0 to n-1, where n is the number of components. The special index value -1 +
Each DynAny object maintains the notion of a current position into its collection
+of component DynAnys. The current position is identified by an index value that runs
+from 0 to n-1, where n is the number of components. The special index value -1
indicates a current position that points nowhere.
For values that cannot have a current position (such as an empty exception),
the index value is fixed at -1.
- If a DynAny is initialized with a value that has components, the index is
+ If a DynAny is initialized with a value that has components, the index is
initialized to 0.
- After creation of an uninitialized DynAny (that is, a DynAny that
+ After creation of an uninitialized DynAny (that is, a DynAny that
has no value but a TypeCode
that permits components), the current position depends on the type of value represented by
- the DynAny. (The current position is set to 0 or -1, depending on whether the
+ the DynAny. (The current position is set to 0 or -1, depending on whether the
new DynAny
gets default values for its components.)
-
-
-
The iteration operations rewind, seek, and next
+
+
+
The iteration operations rewind, seek, and next
can be used to change the current position
- and the current_component operation returns the component at the current
+ and the current_component operation returns the component at the current
position.
- The component_count operation returns the number of components of a
+ The component_count operation returns the number of components of a
DynAny.
- Collectively, these operations enable iteration over the components of a
+ Collectively, these operations enable iteration over the components of a
DynAny, for example,
to (recursively) examine its contents.
-
A constructed DynAny object is a DynAny object associated with
+
A constructed DynAny object is a DynAny object associated with
a constructed type.
- There is a different interface, inheriting from the DynAny interface,
+ There is a different interface, inheriting from the DynAny interface,
associated with
each kind of constructed type in IDL (fixed, enum, struct, sequence, union, array,
- exception, and value type). A constructed DynAny object exports operations
+ exception, and value type). A constructed DynAny object exports operations
that enable the creation of new DynAny objects,
each of them associated with a component of the constructed data value.
- As an example, a DynStruct is associated with a struct value. This
+ As an example, a DynStruct is associated with a struct value. This
means that the DynStruct
may be seen as owning an ordered collection of components, one for each structure member.
- The DynStruct object exports operations that enable the creation of new
+ The DynStruct object exports operations that enable the creation of new
DynAny objects,
each of them associated with a member of the struct.
-
-
-
If a DynAny object has been obtained from another (constructed)
+
+
+
If a DynAny object has been obtained from another (constructed)
DynAny object,
- such as a DynAny representing a structure member that was created from a
+ such as a DynAny representing a structure member that was created from a
DynStruct,
the member DynAny is logically contained in the DynStruct.
- Calling an insert or get operation leaves the current position
+ Calling an insert or get operation leaves the current position
unchanged.
- Destroying a top-level DynAny object (one that was not obtained as a component
+ Destroying a top-level DynAny object (one that was not obtained as a component
of another DynAny)
also destroys any component DynAny objects obtained from it.
Destroying a non-top level DynAny object does nothing.
- Invoking operations on a destroyed top-level DynAny or any of its descendants
+ Invoking operations on a destroyed top-level DynAny or any of its descendants
raises OBJECT_NOT_EXIST.
- If the programmer wants to destroy a DynAny object but still wants to
+ If the programmer wants to destroy a DynAny object but still wants to
manipulate some component
- of the data value associated with it, then he or she should first create a
+ of the data value associated with it, then he or she should first create a
DynAny for the component
and, after that, make a copy of the created DynAny object.
-
-
-
The behavior of DynAny objects has been defined in order to enable efficient
+
+
+
The behavior of DynAny objects has been defined in order to enable efficient
implementations
- in terms of allocated memory space and speed of access. DynAny objects are
+in terms of allocated memory space and speed of access. DynAny objects are
intended to be used
- for traversing values extracted from anys or constructing values of
+for traversing values extracted from anys or constructing values of
anys at runtime.
- Their use for other purposes is not recommended.
-
-
-
+Their use for other purposes is not recommended.
+
+
+
Insert and get operations are necessary to handle basic
+
+
Insert and get operations are necessary to handle basic
DynAny objects
but are also helpful to handle constructed DynAny objects.
Inserting a basic data type value into a constructed DynAny object
@@ -145,9 +145,8 @@ equivalent to
the TypeCode contained in the DynAny or, if the
DynAny has components, is equivalent to the TypeCode
of the DynAny at the current position.
-
+
Basic operations include: -
DynAny and DynAnyFactory objects are intended to be local to
+
+
+
DynAny and DynAnyFactory objects are intended to be local to
the process in which they are
- created and used. This means that references to DynAny and
+ created and used. This means that references to DynAny and
DynAnyFactory objects cannot be exported
to other processes, or externalized with ORB.object_to_string().
- If any attempt is made to do so, the offending operation will raise a MARSHAL system
+ If any attempt is made to do so, the offending operation will raise a MARSHAL system
exception.
- Since their interfaces are specified in IDL, DynAny objects export operations
+ Since their interfaces are specified in IDL, DynAny objects export operations
defined in the standard
- org.omg.CORBA.Object interface. However, any attempt to invoke operations
+ org.omg.CORBA.Object interface. However, any attempt to invoke operations
exported through the Object
interface may raise the standard NO_IMPLEMENT exception.
- An attempt to use a DynAny object with the DII may raise the NO_IMPLEMENT
+ An attempt to use a DynAny object with the DII may raise the NO_IMPLEMENT
exception.
For a precise list of supported sections of official specifications with which
-the Java[tm] Platform, Standard Edition 6 ORB complies, see Official Specifications for CORBA
+ For a precise list of supported sections of official specifications with which
+the Java[tm] Platform, Standard Edition 6 ORB complies, see Official Specifications for CORBA
support in Java[tm] SE 6.
@since 1.4