Introduction to Natural Construct

This document is intended for programmers who have never used Natural Construct. It introduces new users to the basic features and functions of the generation environment, as well as how Natural Construct works.

To get acquainted with the generation environment, follow the step-by-step instructions to create a simple menu program for an order entry application. If you encounter problems, try one or more of the following suggestions:

• Display the online help as follows:

  • To view the help for a panel, press the help (PF1) key while the cursor is anywhere on the panel except an input field.

  • To view the help for an input field or select a parameter from a pop-up window, press PF1 or type "?" and press Enter when the cursor is in the field.

  Note:
  If you do not specify a required parameter, or enter an incorrect one, Natural Construct will prompt you for the correct information.

• Check relevant sections of Natural Construct Generation.

• Visit our web site at www.softwareag.com to get timely product information, correspond with customer support representatives, or access related documents.

Although this guide deals mainly with the generation subsystem, Natural Construct contains two other subsystems. For information, see Help Subsystem, and Administration Subsystem.

This document covers the following topics:

• What is Natural Construct?

• How Does Natural Construct Work?

• Generate a Simple Program

• Creating Specification Documents

• Utilities Supplied with Natural Construct

What is Natural Construct?

Natural Construct is a powerful, easy-to-use, model-based application generator that helps you create and implement high-quality, robust Natural applications. It is built around and uses existing Natural facilities, which means that Natural Construct-generated applications can be deployed on most platforms or distributed across multi-tiered environments.

To Natural's production-oriented development environment and portable execution environment, Natural Construct adds:

• a code generator (at a statement, as well as Natural object level)

• a help maintenance system

• a model maintenance system

These subsystems are described in the following sections.

Generation Subsystem

As a code generator, Natural Construct offers a wide range of reusable program structures, called models. These models allow even inexperienced programmers to generate fully functional applications using high-level, fill-in-the-blank specifications. And Natural Construct uses data defined in Predict, Software AG's data dictionary, to provide the default model specifications, such as local views and field prompts. You can also create your own verification or referential integrity rules in Predict for use with your Natural Construct-generated applications.

Help Subsystem

The help subsystem is designed for non-programmers. It separates the coding of an application from the creation of the online documentation. This separation allows business users or technical writers to write the online help information and programmers to concentrate on programming. In addition, the help subsystem supports multi-lingual help text. For information about this subsystem, see Natural Construct Help Text.

Administration Subsystem

The administration and modeling subsystem is used mainly by administrators. It allows them to modify the models supplied in the generation subsystem, create new models, and set security standards. For information about this subsystem, see Natural Construct Administration and Modeling.

Benefits of Using Natural Construct

There are many good reasons for using Natural Construct to create Natural applications. For example, you can:

• Reduce development efforts by 50% (as reported by many customers)

• Reduce training time and increase acceptance of new applications, as the generated programs have a consistent interface

• Decrease the development time for complex applications and make fewer mistakes

• Reduce checking and testing requirements; you can concentrate on the customized code

• Reduce maintenance efforts by including business rules within the generated objects

• Easily regenerate applications as requirements change

How Does Natural Construct Work?

Natural Construct is based on the premise that most applications have common functional blocks of code. These blocks of code became object templates, called models, which ensure that the required and expected aspects of each object type are incorporated into the generated object in a standard way.

Rather than re-engineering redundant routines each time you create an object, you can use the Natural Construct models to produce functionality-rich business applications that incorporate state-of-the-art technology.

Natural Construct uses the following information to generate an object:

• The chosen model

• The model specifications supplied by the programmer

• Predict data, as required

• Data coded in the user exits (optional)

For more information about designing or implementing a Natural Construct application, see Implementation Methodology or Design Methodology in Natural Construct Generation.

Choosing a Model

Natural Construct supplies more than 100 models, which are available through the Generation main menu. These models generate various programs, subprograms, helproutines, data areas, maps, Natural statements, etc. You can also invoke the statement models from the Natural and User Exit editors.

For client/server environments, Natural Construct provides a series of object maintenance and browse models (Object-Maint and Object-Browse models). In addition, Natural Construct supplies user exit models to assist you in writing user exit code.

Which model you choose depends on what you are doing. For example:

Basically, the models can be grouped into four categories:

• conventional

• client/server

• statement

• user exit

Choose the model that provides the functionality you require. For example, to create the sample menu program later in this documentation, you'll use the Menu model. The following sections describe the most commonly used models in each category.

Conventional Models

These models generate non-distributed programs, subprograms, helproutines, data areas, and maps. The models in this category include:

For more information about these models, see the applicable section in Natural Construct Generation. For an example of using the Menu model, see Generate a Simple Program.

Client/Server Models

The models in this category generate the components required for a client/server application. They include:

For more information about the client/server models, see the applicable section in Natural Construct Generation. For an example of creating an object maintenance process, see Generate a Business Object.

Statement Models

The statement models generate blocks of code containing one or more Natural statements, which you can use as building blocks when creating user exit code or specialized programs. Using the statement models assists you with the statement syntax and reduces the time required to write recurring code segments and test your code.

Typically, you invoke the statement models from the User Exit and Natural editors using a .g line command and the model name in brackets. For example, enter .g(view) to invoke the View statement model. Enter the .g commands in the same position as other line commands, such as the .i (insert) or .d (delete) command.

A few of the commonly used statement models are:

Natural Construct supplies more than 40 statement models. For information about these models, see Statement Models in Natural Construct Generation. For an example of using statement models, see Writing Natural Statements.

User Exit Models

These models generate text member modules containing the field layout specifications for an object browse dialog. The models are invoked from the User Exit editor using the User-Exit statement model. The user exit models are:

For more information, see User Exit Models and User-Exit Statement Model in Natural Construct Generation.

Defining the Model Specifications

Each model has at least one specification panel to collect specifications that are common to the code generated by that model. To help you fill in the parameters, most models supply default values for key fields. You need only specify any additional parameters the model requires to generate the appropriate code.

To create a menu program, for example, you must specify the following parameters:

• A menu heading

• The codes a user types to access options listed on the menu

• Descriptions of the options

• The name of the program executed to perform each option

Other parameters allow you to include optional features in your program.

Defining the Predict Data

Predict is a data dictionary system that centrally stores and manages all information about the metadata (data about data) for an organization. Natural Construct can use the metadata to accurately and consistently generate application code. Although a Natural Construct-generated application can be executed without Predict, the code generator relies on this metadata.

The main advantage of using Predict is that you can change the metadata and then regenerate the code to reflect the changes. For example, you can change a relationship between files in Predict, regenerate the code, and the new relationship is automatically incorporated.

Natural Construct uses the Predict metadata that describes:

• File relationships, such as restricted or cascade delete constraints

• File layouts

• Field attributes, such as maximum occurrences, redefinitions, edit masks, validation rules, and headings

• Field descriptions (for online help)

You can also create Predict metadata by documenting generated Natural objects. This option is available when you generate an object.

For more information about using Predict with Natural Construct, see Use of Predict in Natural Construct and Defining Objects and Relationships in Natural Construct Generation.

Defining User Exits

When specific customizations are required to fulfill your business needs, you can add additional code in a user exit. User exits are strategic points in the model outline, such as at the start of the program or after input. You choose which user exit you want based on the location of the exit within the code. If you are unsure of the location of a user exit, you can generate and edit the Natural object. The position of each user exit is shown in comments that begin with ** SAG Exit Point followed by the name of a user exit. For example:

** SAG Exit Point Change-History

These pointers indicate where the exit will be located in the generated code.

You enter user exit code in the User Exit editor, which you can access from the last specification panel for a model or when you enter U in the Function field on the Generation main menu. If you forget to choose an exit, you can display a list of available exits by entering "SAMPLE" on the command line in the editor.

You can place any Natural code within a user exit. The user exit code becomes part of the object's source code. If you regenerate the object, changes to the user exit code are always preserved.

Many models supplied with Natural Construct have user exits available. When you're creating an object, select the user exits you require and supply the appropriate code for each user exit. Natural Construct uses both the model specifications and the user exit code to create an object.

For more information, see User Exits for the Generation Models in Natural Construct Generation.

Generate a Simple Program

You're now ready to use Natural Construct to generate your first program the main menu for an order entry system. A main menu provides users with a selection of functions available within a system, such as the Generation main menu.

After generating the menu, you'll make a few changes to the specifications and regenerate the program.

The following diagram shows the modules used for the sample menu program:

Before You Begin

The sample menu, as well as other sample programs described in this guide, require access to several modules used in the Natural Construct demo system. The demo system is a fully functional order entry system that was generated using the Natural Construct models (see Natural Construct Demo System in Natural Construct Generation). Natural Construct supplies the following demo systems:

• SYSCSTDE (Adabas)

• SYSCSTD2 (DB2)

• SYSCSTDV (VSAM)

• SYSCSTDS (SQL)

Before beginning this procedure, use the Natural SYSMAIN utility to copy the following modules from the demo library into your user library:

Generating the Menu Program

This section describes how to use the Menu model to generate a menu program.

To generate the menu program

1. At the Natural prompt, logon to your Natural Construct library.

2. Enter "ncstg". The Generation main menu is displayed:

   CSGMAIN N a t u r a l C o n s t r u c t CSGMNM0 Oct 22 Generation Main Menu 1 of 1 Functions ----------------------------------------------- R Read Specifications M Modify Specifications U User Exit Editor G Generate Source T Test Source E Edit Source S Save Source W Stow Source L List Modules C Clear Edit Buffer ? Help . Return ----------------------------------------------- Function ......... _ Module ............. ________ Panel ...... __ Model ............ ________________________________ Type ....... Command .......... ________________________________ Library .... MYLIB Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12--- help quit optns lang

   Tip:
   Typing "M" on the main menu is the equivalent of Create New.

   For more information about the Generation main menu or the Generation subsystem, see Using the Generation Subsystem, in Natural Construct Generation.

3. Specify the following:

   M	Function field
   MYMENU	Module field
   Menu	Model field

   Note:
   If you do not specify a model name, Natural Construct displays a selection window.

4. Press Enter. The Standard Parameters panel for the Menu model is displayed. Notice that some of the fields are filled in for you, based on values you specified on the main menu:

   CUMNMA MENU Program CU--MA0 Oct 22 Standard Parameters 1 of 2 Module ............. MYMENU__ System ............. MYLIB___________________________ Global data area ... CDGDA___ With block ......... ________________________________ Title .............. Menu ..._________________ Description ........ This menu ...__________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ First heading ...... ________________________________________________ Second heading ..... ______________________________________________________ Command ............ _ Message numbers .... _ Password ........... _ Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12--- right help retrn quit right main

5. Type "First Heading for My Menu" in the First header field.

   Note:
   We aren't using the remaining fields on this panel. If you're curious about what these fields are used for, you can type "?" and press Enter to invoke Natural Construct's online help or see General Model Specifications in Natural Construct Generation.

6. Press Enter. The Additional Parameters panel is displayed:

   CUMNMB MENU Program CUMNMB0 Oct 22 Additional Parameters 2 of 2 Map layout ......... ________ * Code Functions____________________________________ Program Name ------ --------------------------------------------- -------------- __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * __ _____________________________________________ ________ * Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12--- help retrn quit optns attr left userX main

   For this example, leave the Map layout field blank. This allows Natural Construct to create a default (internal) map layout. If you've created an external map layout tailored to your shop standards, you could type the name of that map in this field.

   For more information about this panel, press PF1 (help) to invoke the online help or see Additional Parameters Panel in Natural Construct Generation.

7. Specify the following:

   MW	1st Code field
   Maintain Warehouses	On line to the right of the 1st Code field
   NCTFWHSE	1st Program field
   BC	2nd Code field
   Browse Customer Orders	On line to the right of the 2nd Code field
   NCOSCUST	2nd Program field

   These parameters specify the codes the user enters to invoke the corresponding menu functions, the names of the functions, and the names of the programs invoked to perform the function.

8. Press Enter. You are returned to the Generation main menu.

9. Enter "G" in the Function field. A confirmation message is displayed, indicating that the generation was successful.

10. Enter "W" in the Function field. A confirmation message is displayed. Your menu program is now generated and stowed.

    Note:
    For more information about these functions, see Generate Source Function and Stow Generated Source Function in Natural Construct Generation.

    To see the code generated by the Menu model, enter "E" in the Function field.

    To see what the menu will look like to users, enter "T" in the Function field. The following menu is displayed:

    MYMENU ***** First Heading for My Menu ***** Oct 22 5:18 PM Code Functions ---- ------------------------- MW Maintain Warehouses BC Browse Customer Orders ? Help . Terminate ---- ------------------------- Code: __ Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12--- help retrn quit flip main

11. Press PF2 (retrn). You are returned to the Generation main menu.

    You've successfully created a sample menu program. Next, you'll see how easy it is to change a few of the specifications and regenerate the menu program.

    Note:
    If you have any problems creating the menu, see Troubleshooting and Debugging for possible reasons.

Regenerating the Menu Program

This section describes how to change some of the specifications for the menu and then regenerate the program. The procedure begins at the Generation main menu.

To change the specifications and regenerate the menu program

1. Enter "M" in the Function field.

   Note:
   "MYMENU" and "Menu" should be displayed in the Module and Model fields.

   The Standard Parameters panel is displayed, showing the specifications you entered when you created the menu.

2. Enter "Second Heading for My Menu" in the Second header field. The Additional Parameters panel is displayed.

3. Select the word "Functions" and type "Options". On the generated menu, Options will be displayed instead of Functions.

4. Enclose the words "Maintain" and "Browse" within angle brackets (for example, <Maintain>Warehouses and <Browse>Customer Orders).

   Angle brackets are the default intensify characters for Natural Construct. They indicate that the enclosed text is highlighted on the generated menu screen.

   Tip:
   Notice that the intensify characters are placed in the space between words; they do not take up a physical space.

5. Press Enter. You are returned to the Generation main menu.

6. Enter "G" in the Function field. Natural Construct regenerates the menu program, incorporating your changes.

7. Enter "W" in the Function field. Your menu is now regenerated and stowed.

8. Enter "T" in the Function field. The following menu is displayed:

   MYMENU ***** First Heading for My Menu ***** Oct 22 - Second Heading for My Menu - 5:21 PM Code Options ---- ------------------------- MC Maintain Warehouses BW Browse Customer Orders ? Help . Terminate ---- ------------------------- Code: __ Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12--- help retrn quit flip main

   You've successfully changed the specifications and regenerated the menu program. Now that you're familiar with the generation subsystem, see Natural Construct for New Application Development for information about creating a Natural Construct business object.

Creating Specification Documents

A common task an analyst performs is writing the specifications for a new program. Natural Construct can help create a list of questions you can use to create these documents.

• The first question is whether the program will be used in a client/server environment or as a stand-alone program. This answer restricts the range of models you should use.

• The next question is whether the program will query or maintain data, which further restricts the model selection.

Once you've selected a model, you can use the fields on the model specification panels to determine what parameters may be required. For example, the following figure shows the first specification panel for the Menu model:

 CUMNMA                           MENU Program                          CU--MA0 
 Oct 22                       Standard Parameters                        1 of 2 

  Module ............. MYMENU__                                                 
  System ............. MYLIB___________________________                         
  Global data area ... CDGDA___                                                 
  With block ......... ________________________________                         

  Title .............. Menu ..._________________                                
  Description ........ This menu ...__________________________________________  
                       _______________________________________________________  
                       _______________________________________________________  
                       _______________________________________________________  

  First heading ...... ________________________________________________         
  Second heading ..... ______________________________________________________   

  Command ............ _                                                        
  Message numbers .... _                                                        
  Password ........... _                                                        

 Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
 right help  retrn quit                                            right main

Use the fields on this panel to determine what information is required to create the menu program. For example:

• What is the name of the menu program? This question is important if you must adhere to standardized naming conventions.

• What will it do?

• What is the first heading on the menu screen?

• What is the second heading?

• Will the menu allow users to access the Natural command line?

• Will the menu be implemented in different languages?

• Will the menu require security restrictions?

Press Enter to display the Additional Parameters panel and use the fields on that panel to determine other questions you need to answer. Once you have the answers to all these questions, you can easily write the specification document for the menu.

Utilities Supplied with Natural Construct

Natural Construct supplies many utilities to aid in the application development process. These utilities are described in different Natural Construct guides, depending on their function. The following table lists each guide and some of the utilities it describes: