Solstice Enterprise Manager 4.1 Developing C++ Applications Doc Set ContentsPreviousNextIndex

Chapter 6

Performing Management Operations on Object Collections

An object collection is a group of managed objects that your application can treat as a single entity. An object collection simplifies bulk operations by enabling you to select multiple managed objects to be the subject of a management operation. Any management operation that your application performs on an object collection is performed on every managed object in the object collection.

This chapter explains how to perform management operations on object collections.

6.1 Grouping Managed Objects

You are free to choose the managed objects you group into an object collection. However, to ensure that an object collection you create is useful, group objects that are related in a way that is meaningful to your application.

Identify which managed objects are suitable for grouping into an object collection by:

For example, to lock all unlocked channels from a satellite, create an object collection that consists of all instances of the channel managed object class with the administrativeState attribute set to unlocked that are contained in a particular instance of satellite. After you have created the object collection, set the administrativeState attribute of all satellites in the object collection to locked.

Note – Solstice EM allows you to define a managed object to be a member of any number of object collections.

6.2 Creating a Container for an Object Collection

To group objects into an object collection, an application must create a container for the object collection. To create a container for an object collection, create and initialize an instance of the Album class. An instance of the Album class is a container for the managed objects in an object collection. It also provides functions for performing management operations on an object collection.

Solstice EM allows a managed object to be a member of any number of object collections.

Each managed object in an object collection is represented by an instance of the Image class. For more information on the Image class, refer to Chapter 5.

When you call the constructor of the Album class, you must specify a nickname for the Album instance. The nickname uniquely identifies the Album instance. It must be a text string. Spaces are permitted in a nickname.

Code for creating and initializing an instance of the Album class is shown in CODE EXAMPLE 6-1.

CODE EXAMPLE 6-1   Creating and Initializing an Album Instance 
...

#include <pmi/hi.hh>                    // High Level PMI

...

    satellites = Album("collection of all satellites");

...

In this example, an Album instance is created and initialized with the nickname collection of all satellites.

6.3 Defining the Membership of an Object Collection

Defining the membership of an object collection selects managed objects to be grouped into the object collection. Depending where the managed objects are located in the management information tree (MIT), you can define the membership of an object collection by:

If you want an object collection to contain a subtree of the MIT and individual objects or object collections, define the membership of the object collection by using a combination of derivation and enumeration.

6.3.1 Defining the Membership by Derivation

If the managed objects in your object collection are in a subtree of the MIT, define the membership of the object collection by derivation.

Defining the membership of an object collection by derivation involves:

6.3.1.1 Setting a Derivation String

A derivation string selects one or more managed objects in a subtree of the MIT by specifying a base managed object, a scope, and a filter. To set a derivation string, call the set_derivation function of the Album class.

In the call to set_derivation you have to specify the derivation string. For details of the format of a derivation string, refer to Section 6.3.2 Format of a Derivation String.

Calling the set_derivation function does not cause your application to communicate with the MIS. Consequently, the set_derivation returns immediately after it is called, provided no errors occur.

Code for setting a derivation string is shown in CODE EXAMPLE 6-2.

CODE EXAMPLE 6-2   Setting a Derivation String 
...

#include <pmi/hi.hh>                    // High Level PMI 

#include <rw/cstring.h>                 // Rogue Wave RWCString

...

// Set up the distinguished name to start the derivation

        RWCString derive_str;

        derive_str = "/systemId=\"";

        derive_str += server;

        derive_str += "\"/LV(1)";

        derive_str += "/CMISFilter(item:equality:{objectClass,satellite})";


  

  

     

        cout << "Deriving satellites: " << derive_str.data() << endl;


  

  

     


  

  

     

        if 
(!satellites.set_derivation((char *) derive_str.data())) {


  

  

     

                cout << "Failed 
to set derivation string." << endl;


  

  

     

                cout << 
satellites.get_error_string() << endl;


  

  

     

                return;


  

  

     

        }


  

  

     

...


  













   In this example, a derivation string is set up to 
select all instances of the satellite managed object class that are 
one level below the system object 
in the MIT. The system object is 
identified by the value of the server variable. 






   To enable the server 
variable for the host name to be included, the derivation 
string is constructed using a Rogue Wave RWCString object in this example. The 
server variable has already been 
initialized to a text string that contains the host name of 
the machine on which the MIS is running. The initialization 
of the server variable is not 
shown in this example.






   6.3.1.2	 Starting the 
Derivation






   When you have set the derivation sting, start the 
derivation to define the membership of the object collection. 
To start the derivation, call the derive function of the Album class.






   Calling the derive 
function causes your application to retrieve information from 
the MIS. If a large number of managed objects is selected by 
the derivation string, your application will become blocked 
for a long time while it waits for derive to return. If you want your 
application to continue with other processing during a 
lengthy derivation, start the derivation asynchronously as 
described in Chapter 
8.






   Code for starting a derivation is shown in CODE EXAMPLE 6-3. 


 CODE EXAMPLE 6-3 	
  Starting a 
Derivation 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                    // High Level PMI 


  

  

     

...


  

  

     

    if (!satellites.derive()) {


  

  

     

        cout << "Derive failed." << endl;


  

  

     

        cout << satellites.get_error_string() << endl;


  

  

     

        return;


  

  

     

    }


  

  

     

    


  

  

     

...


  













   6.3.2	 Format of a 
Derivation String






   A derivation string selects one or more managed 
objects in a subtree of the MIT by specifying a base managed 
object, a scope, and a filter. The format of a derivation 
string is as follows:



  
  

     

baseMO/scope/filter


  














   Where:






   A forward slash(/) 
separates the base managed object from the scope, and the 
scope from the filter.






   6.3.2.1	 Base Managed 
Object






   The base managed object is the root object of the 
subtree you want to select. Depending on the scope and the 
filter, the base managed object may not be one of the managed 
objects selected by the derivation string.






   The base managed object is identified by one of 
the following:






   The base managed object is optional. If you omit 
it, the system object is assumed. 
If you omit the base managed object, also omit the slash 
required to separate the base managed object from the 
scope.






   6.3.2.2	 Scope






   The scope selects one or more managed objects in 
the subtree rooted at the base managed object. The scope is 
defined with reference to the base managed object. Set the 
scope in a derivation string to one of the values given in TABLE 6-1.



    

   TABLE 6-1 	  Scope Values in a 
Derivation String 
  
 Value

     Selects

  

  

    
 ALL

    
 The base managed object and its entire 
subtree.

  

  

    
 LV(n)

    
 Only level n subordinates of the 
base managed object, where n is an 
integer.

  

  

    
 TO(n)

    
 The base managed object and all its subordinates 
to level n, 
where n is an 
integer.

  

  

    
 *

    
 Only first-level subordinates of the base managed 
object. Equivalent to LV(1).

  

  

    
 */*

    
 Only second-level subordinates of the base 
managed object. Equivalent to LV(2).

  

  

    
 */*/*

    
 Only third-level subordinates of the base managed 
object. Equivalent to LV(3).

  















   The scope is optional. If you omit the scope, 
only the base managed object is selected.






   If the subtree contains a large number of managed 
objects, setting the scope to ALL 
could cause your application to be timed out while it 
retrieves information from the MIS during a derivation. If 
possible, select fewer managed objects by changing the scope 
or by specifying a filter to prevent your application from 
being timed out.






   The effects of these scope values are illustrated 
in FIGURE 6-
1. In FIGURE 6-
1, selected objects are shaded.




 



 FIGURE 6-1 	  Scope 
Values


   6.3.2.3	 Filter






   The filter selects or rejects objects based on 
the presence and values of specific attributes. The filter is 
a boolean expression, which may be a single test or a 
combination of multiple tests. 






   The filter is optional. If you omit it, all 
managed objects identified by the base managed object and 
scope are selected. If you omit the filter, also omit the 
slash required to separate the scope from the filter.






   When a scope and a filter are combined, the scope 
is applied first, then the filter. An example of combining a 
scope and a filter is shown in FIGURE 6-
2. In FIGURE 6-
2, selected objects are shaded.




 



 FIGURE 6-2 	
  Combination of a Scope and a Filter


   A filter contains an optional filter operator and 
one or more filter items. A filter item can in turn be a 
filter.






   The format of a filter in a derivation string is 
as follows:



  
  

     

CMISFilter([filterOperator:] 
{filterItemList})


  














   Where:






   The filter operator and the list of filter items 
are enclosed in parentheses.






   Note – This format is the ASN.1 type 
CMISFilter that is defined in the 
ASN.1 module for ITU-T X.711/ISO-9596-1 Common Management 
Information Protocol Specification (/opt/SUNWconn/em/etc/asn1/x711.asn1). 







   Filter 
Operator






   The filter operator is a logical operator for 
grouping elements in a filter that contains multiple filter 
items. Set the filter operator to one of the keywords given 
in TABLE 6-2
.



    

   TABLE 6-2 	  Filter Operator 
Keywords 
  
 Keyword

     Meaning

  

  

    
 and

    
 Apply boolean and to 
the filter items that follow it.

  

  

    
 or

    
 Apply boolean or to 
the filter items that follow it.

  

  

    
 not

    
 Apply boolean not to 
the filter items that follow it. It can be applied only to 
one filter item.

  















   The filter operator is optional. If you omit it, 
only one filter item is allowed in the filter. If you omit 
the filter operator, also omit the colon that follows 
it.






   Filter 
Item






   A filter item is a single test within a filter. 
The syntax of a filter item depends on whether you want to 
filter on substrings.






   The syntax of a filter item without substrings is 
as follows:



  
  

     

item:comparison:{attributeId[,value]}


  














   Where:






   The attribute identifier and the value are 
enclosed in braces.



    

   TABLE 6-3 	  Comparison Keywords 
in a Filter Without 
Substrings 
  
 Keyword

     Filter Item Evaluated 
to True if

  

  

    
 equality

    
 The managed object contains an attribute of type 
attributeId that 
has a value equal to value.

  

  

    
 greaterOrEqual

    
 value is greater than 
or equal to the value of an attribute of type attributeId that the 
managed object contains.

  

  

    
 lessOrEqual

    
 value is less than or 
equal to the value of an attribute of type attributeId that the 
managed object contains.

  

  

    
 present

    
 The managed object contains an attribute of type 
attributeId.

  

  

    
 subsetOf

    
 value is a subset of a 
set-valued attribute of type attributeId that the 
managed object contains.

  

  

    
 supersetOf 


    
 value is a superset of 
a set-valued attribute of type attributeId that the 
managed object contains.

  

  

    
 nonNullSetIntersection

    
 The managed object contains a set-valued 
attribute of type attributeId and the 
intersection of its value and value is not 
empty.

  















   The syntax of a filter item that includes 
substrings is as follows:



  
  

     

item:substrings:{substringItemList}


  














   Where substringItemList is a 
list of substring items. substringItemList is 
enclosed in braces. Each substring item in the list is 
separated by a comma.






   The syntax of a substring item is as follows:



  
  

     

part:{attributeId,value}


  














   Where:






   The attribute identifier and the value are 
separated by a comma and enclosed in braces.



    

   TABLE 6-4 	  Part Keywords in a 
Substring 
  
 Keyword

     Filter-Item Evaluated 
to True if

  

  

    
 initialString

    
 The managed object contains an attribute of type 
attributeId the 
start of the value of which matches the string specified in 
value.

  

  

    
 anyString

    
 The managed object contains an attribute of type 
attributeId any 
part of the value of which matches the string specified in 
value.

  

  

    
 finalString

    
 The managed object contains an attribute of type 
attributeId the 
end of the value of which matches the string specified in 
value.

  















   6.3.2.4	 Example Derivation 
Strings






   CODE EXAMPLE 6-4 shows the derivation string for selecting 
all log objects.


 CODE EXAMPLE 6-4 	
  Selecting All log 
Objects 




  
  
  

  

     

LV(1)/CMISFilter(item: equality: {objectClass, log})


  













   The object model defines that instances of log are contained in the system object. Therefore, the base 
managed object is not specified in this example because it is 
the system object, which is the 
default.






   CODE EXAMPLE 6-5 shows the derivation string for selecting 
all enabled log objects.


 CODE EXAMPLE 6-5 	
  Selecting All Enabled Instances of log 




  
  
  

  

     

LV(1)/CMISFilter(


  

  

     

    and: {


  

  

     

    item: equality: {objectClass, 
log},


  

  

     

    item: equality: 
{operationalState, enabled}


  

  

     

    }


  

  

     

)


  













   In this example, two filter items are combined 
using the and filter operator. 
The first filter item selects all log objects. The second filter item 
tests the value of the operationalState attribute to select 
only log objects that are 
enabled.






   CODE EXAMPLE 6-6 shows the derivation string for selecting 
all objects that are not instances of the log class.


 CODE EXAMPLE 6-6 	
  Selecting all Objects That are not Instances 
of log 




  
  
  

  

     

ALL/CMISFilter(not:{item:equality:{objectClass,log}})


  













   The derivation strings shown in CODE EXAMPLE 6-7 are all equivalent.


 CODE EXAMPLE 6-7 	
  Equivalent Derivation 
Strings 




  
  
  

  

     

/systemId="mako"/LV(1)/CMISFilter(item:equality:{objectC
lass,log})


  

  

     


  

  

     

LV(1)/CMISFilter(item:equality:{objectClass,log})


  

  

     


  

  

     

*/CMISFilter(item:equality:{objectClass,log})


  













   In this example, each of the derivation strings 
selects all log objects that are 
one level below the system object 
in the MIT.






   6.3.3	 Defining the 
Membership by Enumeration






   If the managed objects in your object collection 
are distributed throughout the MIT, or if you want to add an 
existing object collection, define the membership of the 
object collection by enumeration. 






   Note – If you define the membership 
of an object collection by enumeration, you have to maintain 
the membership of the object collection manually. For more 
information, refer to Section 6.4.1 
Maintaining the Membership of an Object 
Collection.






   To define the membership of the object collection 
by enumeration, call the include 
function of the Album class. The 
include function adds a managed 
object or an object collection to an object 
collection.






   In the call to the include function you have to specify 
one of the following:






   6.4	 Tracking Changes to 
an Object Collection






   Tracking changes to an object collection updates 
an Album instance with changes to 
the object collection that the instance contains. Tracking 
changes ensures that:






   Tracking changes to an object collection 
involves:






   6.4.1	 Maintaining the 
Membership of an Object Collection






   Maintaining the membership of an object 
collection ensures that the object collection accurately 
reflects the current state of your network. In a live 
network, managed objects are continually created and deleted 
as managed resources are added to and removed from the 
network management environment. Attribute values change as a 
result of activity on the network. All of these changes 
affect the membership of an object collection. 






   Depending on your performance requirements, you 
can maintain the membership of an object collection 
automatically or manually. Automatically maintaining the 
membership requires you to write less code but is less 
efficient than manually tracking changes. Furthermore, when 
you maintain the membership of an object collection 
automatically, all historical information on the membership 
the object collection is lost.






   6.4.1.1	 Automatically 
Maintaining the Membership of an Object Collection






   Automatically maintaining the membership of an 
object collection causes the Album instance that contains the object 
collection to update the object collection by:






   Maintain the membership of an object collection 
automatically in any of the following circumstances: 






   To maintain the membership of an object 
collection automatically, set the TRACKMODE property of the Album instance to TRACK. To set the TRACKMODE property of an Album instance, call the set_prop function of the Album class before defining the 
membership of the object collection that the instance 
contains.






   Code for setting the TRACKMODE property to TRACK is shown in CODE EXAMPLE 6-8.


 CODE EXAMPLE 6-8 	
  Setting the TACKMODE Property of an Album 
Instance 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                    // High Level PMI


  

  

     

...


  

  

     

        // Automatically add Image objects to the Album object 


  

  

     

        // based on derivation rules


  

  

     

        //


  

  

     

        if (!satellites.set_prop(duTRACKMODE, duTRACK)) {


  

  

     

                cout << satellites.get_error_string() << endl;


  

  

     

                return;


  

  

     

        }


  

  

     

...


  













   6.4.1.2	 Manually Maintaining 
the Membership of an Object Collection






   Maintain the membership of an object collection 
manually if you need fast response from your application, or 
if you need to preserve historical information on the 
membership the object collection. 






   Maintaining the membership of an object 
collection manually involves:






   If you maintain the membership of an object 
collection manually, you have to write in your callback 
functions code for adding objects to or removing objects from 
the object collection. Having to write your own code makes 
coding your application more complicated. But it gives you 
control over which changes you update the object collection 
with, and enhances the performance of your application. 







   Use the following functions of the Album class in your callbacks to add 
objects to or remove objects from an object 
collection:






   In the call to the include or exclude function you have to specify 
one of the following:






   Code for using callback functions to update the 
membership of the object collection is shown in CODE EXAMPLE 6-9.


 CODE EXAMPLE 6-9 	
  Using Callback Functions With an Object Collection 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                 // High Level PMI 


  

  

     

#include <rw/cstring.h>              // Rogue Wave RWCString


  

  

     

...


  

  

     

    // Register for callbacks when a new Image object is deleted.


  

  

     

    //


  

  

     
    if (!satellites.when("OBJECT_DESTROYED", Callback(remove_cb,0))) 
{


  

  

     

        cout << satellites.get_error_string() << endl;


  

  

     

        return;


  

  

     

    }


  

  

     

...


  

  

     

void remove_cb( Ptr, Ptr calldata)


  

  

     

{


  

  

     

        CurrentEvent ce(calldata);


  

  

     

        ce.do_something();


  

  

     

        cout << "*****Removing from the Album ";


  

  

     

        RWCString event_class(ce.get_objclass().chp());


  

  

     

        Image tmpimage(ce.get_objname());


  

  

     

        if (event_class.contains("dish")) {


  

  

     

                cout << "dishes*****" << endl;


  

  

     

                dishes.exclude(tmpimage);


  

  

     

        } else if (event_class.contains("channel")) {


  

  

     

                cout << "channels*****" << endl;


  

  

     

                channels.exclude(tmpimage);


  

  

     

        }


  

  

     

...


  

  

     

}


  













   In this example, the remove_cb callback is called whenever 
the application receives a notification that a managed object 
has been deleted. When the remove_cb callback is called, the 
application extracts from the event information required to 
determine if the managed object is a member of an object 
collection maintained by the application. If it is, the 
exclude function of the Album 
class is called to remove the object from the object 
collection.






   For more information on how to use callback 
functions, refer to Section 7.2 Processing 
Information in Event Notifications. 






   6.4.2	 Setting the Mode of 
an Object Collection






   The mode of an object collection specifies how 
Image instances are activated and 
tracked when they are added to an object collection. The mode 
is one of the following:






   For more information, refer to Section 5.2.2 
Activating the Instance of Image and Section 5.9 
Tracking Changes to an Object.






   To set the mode of an object collection, set the 
AUTOIMAGE property of the Album instance as follows:






   To set the AUTOIMAGE 
property of an Album instance, 
call the set_prop function of the 
Album class before defining the 
membership of the object collection that the instance 
contains.






   Code for setting the mode of an object collection 
is shown in CODE EXAMPLE 6-10.


 CODE EXAMPLE 6-10 	
  Setting the Mode of an Object Collection 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                    // High Level PMI 


  

  

     

...


  

  

     

        // By default, an Image object is in the down state and 


  

  

     

        // read only.


  

  

     

        // Specify automatic activation of new Image objects


  

  

     

        // which are children of the derivation FDN


  

  

     

        //

  

  

     

        if (!satellites.set_prop(duAUTOIMAGE, duYES)) {


  

  

     

                cout << satellites.get_error_string() << endl;


  

  

     

                return;


  

  

     

        }


  

  

     

...


  













   In this example, the overloaded NOT (!) 
operator acts on the call to set_prop to verify that the mode of the 
object collection was set to automatic. If the mode was not 
set, an error message explaining the reason for the failure 
is displayed.






   6.5	 Accessing All 
Objects in an Object Collection






   Accessing all objects in an object collection 
enables you to perform the same management operation on 
several managed objects simultaneously. You access all the 
objects in an object collection by performing management 
operations on the object collection. Any management operation 
performed on an object collection is performed on every 
managed object in the object collection.






   The following management operations are permitted 
on an object collection:






   These management operations are described in 
detail for individual managed objects in Chapter 
5.






   When you perform a management operation on an 
object collection you have to set the synchronization of the 
object collection. The synchronization specifies how the 
collection reacts to a management operation that only some 
objects in the collection are able to perform.






   6.5.1	 Adding All Objects 
in an Object Collection to the MIS






   Each object in an object collection is 
represented by an instance of the Image class. An instance of the Image class is a local representation 
of an object. A local representation is cached within your 
network management application. The actual object is in the 
MIS. If the managed objects in a collection do not already 
exist in the MIS, you can add them to the MIS in a single 
operation. To add all objects in an object collection to the 
MIS, call the all_create function 
of the Album class.






   In the call to the all_create function, you can set an 
optional timeout to specify the maximum length of time 
allowed for adding an object in the object collection to the 
MIS. The timer used for this timeout is reset each time an 
object in the object collection is added to the MIS.






   6.5.2	 Deleting All Objects 
in an Object Collection






   Deleting all objects in an object collection 
removes the managed resources represented by the objects in 
the collection from the network management environment. The 
conditions under which an object in an object collection is 
permitted to be deleted are defined in the GDMO specification 
of the managed object. For more information, refer to Section 5.5 
Deleting a Managed Object.






   To delete all objects in an object collection, 
call the all_destroy function of 
the Album class. The all_destroy function removes all 
objects in the object collection from the MIS. 






   In the call to the all_destroy function, you can set an 
optional timeout to specify the maximum length of time 
allowed for deleting an object in the object collection. The 
timer used for this timeout is reset each time an object in 
the object collection is deleted.






   Note – The Album instance that contains the object 
collection remains in existence after all objects in the 
object collection have been deleted. 






   6.5.3	 Setting Attribute 
Values of All Objects in an Object Collection






   To control the managed resources represented by 
the objects in an object collection, an application sets 
attribute values of all objects in the collection. Setting 
attribute values of all objects in an object collection 
applies the same control operation to all objects in the 
collection.






   The conditions under which an object attribute is 
permitted to be set are defined in the GDMO specification of 
the managed object. For more information, refer to Section 5.7 
Setting Attribute Values of an Object.






   Setting an attribute value of all objects in an 
object collection involves:






   6.5.3.1	 Setting an Attribute 
Value in the Image 
Instances






   To set an attribute value in the Image instances that represent the 
objects in an object collection, call one of the functions of 
the Album class listed in TABLE 6-5
, depending on the data type of the attribute.



    

   TABLE 6-5 	  Functions for Setting 
Attribute Values in an Object 
Collection 
  
 Data 
Type

     Function

  

  

    
 String

    
 all_set_str

  

  

    
 Integer

    
 all_set_long

  

  

    
 Real

    
 all_set_dbl

  

  

    
 Arbitrarily long integer

    
 all_set_gint

  

  

    
 Any complex ASN.1 type

    
 all_set_raw

  















   In the call to a function for setting an 
attribute value, you have to specify:






   6.5.3.2	 Updating the MIS 
With the Changed Values






   After you have set the attribute in the Image instances, update the MIS with 
the changed values to propagate the changes to the managed 
objects themselves. To update the MIS with the changed 
values, call the all_store 
function of the Album 
class.






   6.5.4	 Performing an Action 
on an All Objects in an Object Collection






   An action is an operation that cannot be modelled 
by a pre-defined operation such as getting or setting an 
attribute. An action enables you to implement specialized 
behavior, for example, changing attributes of one or many 
objects in a single operation or providing the results of a 
query in a particular format.






   To send an action request to an object 
collection, call the all_call 
function of the Album 
class.






   In the call to all_call, specify:






   6.5.5	 Setting the 
Synchronization of an Object Collection






   The synchronization of an object collection 
specifies whether a management operation has to be successful 
for all the objects in the object collection if it is to be 
performed. The synchronization is one of the 
following:






   To set the synchronization of an object 
collection, set the BEST_EFFORT 
property of the Album instance as 
follows:






   To set the BEST_EFFORT property of an Album instance, call the set_prop function of the Album class before defining the 
membership of the object collection that the instance 
contains.






   6.6	 Accessing Individual 
Objects in an Object Collection






   Access individual objects in an object collection 
if you want to:






   Accessing individual objects in an object 
collection also provides information on the membership of an 
object collection.






   To access individual objects in an object 
collection, use the AlbumImage 
class to retrieve each object from an object collection. An 
instance of the AlbumImage class 
represents the current Image 
instance in a list of Image 
instances or the current Album 
instance in a list of Album 
instances.






   Retrieving each object from an object collection 
involves:






   Code for retrieving each object from an object 
collection is shown in CODE EXAMPLE 6-11.


 CODE EXAMPLE 6-11 	
  Retrieving Objects From an Object 
Collection 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                    // High Level PMI 


  

  

     

...


  

  

     

Album                   dishes;        // Collection of dish objects


  

  

     

...


  

  

     

// Get and print each object in the Album object.


  

  

     

        AlbumImage ali;


  

  

     

        for (ali = dishes.first_image(); ali; ali = ali.next_image()) {


  

  

     

                Image im(ali);


  

  

     

                if (im.get_error_type() != PMI_SUCCESS) {


  

  

     

                        cout << im.get_error_string() << endl;


  

  

     

                        exit(8);


  

  

     

                }


  

  

     

                DU objname = im.get_objname();


  

  

     


  

  

     

                cout << endl;


  

  

     

                cout << "Dish Name: ";


  

  

     

                cout << objname.chp() << endl;


  

  

     

         }


  

  

     

...


  













   In this example, an instance of Image is created for each object in the object collection as follows:






   The FDN of each Image instance created is obtained by calling the get_objname function of the Image class. Each FDN obtained is printed.






   When the final Image 
instance has been reached, the next_image function returns NULL, thereby terminating the for loop.






   6.7	 Obtaining All Object 
Collections for an Object 






   Obtaining all object collections for an object 
keeps track of which object collections a managed object is a 
member of. By keeping track of which object collections a 
managed object is a member of, you can exclude a managed 
object from a collection when you no longer want operations 
on the collection to be applied to the managed object.






   Obtaining all object collections for an object 
involves:






   Code for obtaining all object collections for an 
object is shown in CODE EXAMPLE 6-12.


 CODE EXAMPLE 6-12 	
  Obtaining all Object Collections for an 
Object 




  
  
  

  

     

...


  

  

     

#include <pmi/hi.hh>                    // High Level PMI 


  

  

     

...


  

  

     


  

  

     

Image img (DU(fdn)); // Managed object already exists,so no MOC


  

  

     

...


  

  

     

// Get and print each Album instance that contains the object

  

  

     

        AlbumImage albimg;


  

  

     

        for (albimg = img.first_album(); albimg; albimg = albimg.next_album()) {


  

  

     

                Album alb(albimg);


  

  

     

                if (alb.get_error_type() != PMI_SUCCESS) {


  

  

     

                        cout << alb.get_error_string() << endl;


  

  

     

                        exit(8);


  

  

     

                }


  

  

     


  

  

     

                DU albname = alb.get_prop(duNICKNAME);


  

  

     


  

  

     

                cout << endl;


  

  

     

                cout << "Album Nickname: ";

  

  

     

                cout << albname.chp() << endl;


  

  

     

         }


  

  

     

...


  













   In this example, an instance of Album is created for each object 
collection that the object is a member of as follows:






   The nickname of each Album instance created is obtained by 
calling the get_prop function of 
the Album class. Each nickname 
obtained is printed.






   When the final Album 
instance has been reached, the next_album function returns NULL, thereby terminating the for loop.

















Sun Microsystems, Inc.

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