Category: ZOM Concepts

Zim applications consist of collections of objects, each of which has a specific purpose and a set of features. These objects are described in the Object Dictionary. These various types of objects are

The Object Dictionary is arranged such that all objects of the same type are grouped together. This is very convenient for working with objects of the same type, but dealing with objects in general is not so easy. A simple example illustrates this point. To see the descriptions of all EntitySets with names starting with ” Inv”, enter the following command:

list all Ents where EntName like " Inv%"

To see descriptions of all objects with names starting with ” Inv”, enter the following series of steps, one for each type of object:

list all Ents where EntName like " Inv%"
list all Rels where RelName like " Inv%"
list all Roles where RoleName like " Inv%"

and so on.

ZOM, on the other hand, treats all objects the same, regardless of type, and enables you to operate on them together. This homogenous view of objects enables, for example, all objects with names starting with ” Inv” to be retrieved in a single step:

ZOMList Inv*

ZOMList, which lists information about objects, is just one of the ZOM services. As you can see from this example, treating application objects homogeneously can lead to significant time savings and very powerful operations. ZOM provides extensive capabilities for selecting and manipulating objects that operate over the entire universe of application objects.

Note: ZOM does not deal with FormField and Field objects as independent objects, but instead works with the parent objects (e.g., Forms, EntitySets, Relationship, etc.).

For each object registered, ZOM records several properties that identify the object and track the object’s state. Some of these properties are set automatically by ZOM, while others are designated manually by the user. These properties are then used by the ZOM services in processing objects and can be used by you to select the objects to process.

Identification Properties

The identification properties ZOM can use to identify an object are

Status Properties

The status properties ZOM uses to record the state of an object are

Properties are set at different times and in different ways. The identification properties, with the exception of Keywords, are set initially by ZOM when an object is registered and maintained automatically by ZOM. Keywords are assigned to objects explicitly by the user. The status properties, with the exception of user-designated properties, are set by ZOM when an object is touched. These properties are also automatically updated by ZOM when a ZOM service changes the object’s state. The user-designated properties are explicitly set by the user.

ZOM is an integrated component for object management. It is highly recommended that it remains on permanently to obtain the benefits of analyzing and manipulating objects. If you are using ZOM on the command line, you must first enable ZOM before using any of the object management services during a Zim session. This is done by invoking ZOMEnable as shown in the following example:

ZOMEnable

This procedure initializes the ZOM for the session and searches its Object Dictionary for any objects that are unknown to the ZOM. These objects are automatically “registered” in the ZOM object database. (The registration of the object is described later in this section.)

If you plan to make regular use of ZOM from the command line, it is recommended to run ZOMEnable in your startup program (ie, ZimPROF) while developing an application.

If, during a session, you want to shut down ZOM, issue the ZOMDisable command as shown in the following example:

ZOMDisable

ZOM keeps track of two types of information about objects:

1. object attributes such as the object’s name and type
2. object dependencies such as the fact that a program uses (i.e. refers to) other objects

Because object descriptions can be added to the object dictionary at any time, when you invoke a ZOM command, ZOM does a quick check for new objects. New objects are “registered”, meaning they are assigned a unique object key and are known to ZOM. Dependency information is updated by ZOM commands that can change dependencies (e.g. ZOMCompile and ZOMReCreate). Of course, you can still create and compile using the regular Zim commands, meaning that ZOM’s dependency information can be out-of-date. The ZOMTouch command can be used to examine objects and update the dependency information.

With that in mind, the first time you use the ZOM, you will need to make the ZOM “aware” of the objects in your application. The simplest way to do this is to “touch” all objects in your application using the ZOMTouch command.

For each object encountered, ZOMTouch records information such as the object’s name, type, and location. In addition, the object’s current state is recorded along with any dependencies between the object and other objects in the application.

If you have a large number of objects in your application, the process can take a considerable amount of time. Consider executing ZOMTouch overnight or at some other convenient time. Once ZOMTouch has finished processing, ZOM has a complete picture of the objects in your application and the interdependencies between these objects.

ZOM, or ZIM Object Management, provides extensive support for managing the objects that make up your applications.

ZOM is a collection of services that assist you in manipulating, analyzing, and maintaining application objects, including programs. These services also support you in managing development projects, migrating applications to new computer systems, and building custom development tools such as program generators.

ZOM services are available as a collection of command line utilities. In this section, examples of ZOM are shown at the command prompt. ZOM Services help developers manipulate and analyze application objects provide a powerful set-oriented method of investigating and managing objects and object dependencies provide a homogeneous view of objects independent of object type provide facilities to co-ordinate development projects and development teams provide high-level services for use in building custom development tools.

ZOM features the following facilities:

• support for the creation and destruction of objects and their definitions
• object query and analysis
• object dependency processing
• object import, export, comparison and conversion utilities
• keyword indexing of objects.

ZOM also provides a solid foundation for creating custom tools to support your special development needs and to automate repetitive tasks. Code generation, version control, application deployment, application porting, and other tasks can be automated using ZOM.

All objects must be assigned valid directory names in your Object Dictionary to be accessible in ZOM. In other words, the directory name (i.e., DirName) attributes in your Object Dictionary must be assigned and cannot be left blank or null.

If you have objects defined in multiple directories, you must complete the DirName and FormDirName fields in the Object Dictionary (if they are blank or null) prior to using ZOM. If you do not, the ZOM services automatically assign a default directory name.

Note: You can select a default directory by using the ZOM configuration facility, ZOMConfig. Initially, the default directory is “Zim”.