Hello World Example

This page goes through a simple "Hello World" example in ADOxx.

Introduction

This example produces a simple modelling tool which allows to create two types of objects ("Hello" and "World") and relations to connect the objects. The desired result for a modelling tool should look something like:

The general approach in this case is:

1. Create a library.
2. Create the relevant classes and configure their details.
3. Specify a model type.

All of the steps are performed in the Development Toolkit, so start the Development Toolkit and log in with the Admin user before continuing.

Create Hello World Library

Application Libraries are not created from scratch. Instead they are created as a copy from an existing one. This can be achieved with the following steps:

1. Select the Library management component in the Development Toolkit.
2. Select Libraries -> Management... in the menu or the Management icon in the quick access bar.
3. Select the "ADOxx ... OMiLAB Starting Library ...".
4. Select the Create copy... button.
5. When prompted enter a new name for the three libraries and select OK:
   • Application library name: Hello World
   • Dynamic library name: Hello World (Dynamic)
   • Static library name: Hello World (Static)
6. Confirm the pop-up dialog.
7. Close the Library Management dialog.

For more details on application libraries see the Application Library page.

Create Hello World Classes

Creating and configuring classes is achieved through the class-hierarchy dialog in ADOxx.

Open the Class-Hierarchy

First it is necessary to open the class-hierarchy dialog for the library:

1. Select the Library management component in the Development Toolkit.
2. Select Libraries -> Settings... in the menu or the Settings icon in the quick access bar.
3. Open the "Hello World" library by selecting the icon next to it and select the "Hello World (Dynamic)" library.
4. Select the Class hierarchy... button.
5. Under View activate both Metamodel and Class hierarchy.
6. Open the __D-construct__ class by selecting the icon next to it.

Create Hello and World Classes

Create the two classes through the class-hierarchy dialog:

1. Select the __D-construct__ class.
2. Select New -> New class... on the right side of the dialog.
3. Enter Hello as the class name. __D-construct__ should be listed under Superclass.
4. Select Ok.
5. Select the __D-construct__ class again.
6. Select New -> New class... on the right side of the dialog.
7. Enter World as the class name. __D-construct__ should be listed under Superclass.
8. Select Ok.

For more details on classes see the classes page.

Specify Hello and World Notations

For the classes to be visible it is necessary to specify their graphical representation, which is achieved through the class-hierarchy dialog:

1. Open the Hello class by selecting the icon next to it.
2. Double click on the GraphRep attribute underneath the Hello class.
3. Enter the following value for Standard value:

   GRAPHREP
   RECTANGLE x:-1.5cm y:-1cm w:3cm h:2cm
   TEXT "Hello" w:c h:c

4. Select Close
5. Open the World class by selecting the icon next to it.
6. Double click on the GraphRep attribute underneath the World class.
7. Enter the following value for Standard value:

   GRAPHREP
   RECTANGLE x:-1.5cm y:-1cm w:3cm h:2cm
   TEXT "World" w:c h:c

8. Select Close

Selecting the correct GraphRep attribute

Be careful to select the right GraphRep attribute: The attributes at the end of the list belong to __D-construct__, not World! Use the lines coming from the icons of the attribute to determine what class they belong to.

For more details on the notation of classes see the the special attribute GraphRep.

Create HelloAnything Relation Class

To create a relation class perform the following steps in the class-hierarchy dialog:

1. Select Relation classes at the bottom of the class-hierarchy dialog.
2. Select New -> New relationclass... on the right side of the dialog.
3. Enter HelloAnything as the class name.
4. For from-class select Hello and for to-class select __D-construct__.
5. Select Ok

For more details on classes see the classes page.

Specify HelloAnything Notations

Relation classes have a default notation that is used if none is specified. The default notation is a thin black line, which is also the desired notation for the example.

The notation could be changed similar to the Hello and World classes by editing the GraphRep attribute.

Save Changes to Class-Hierarchy

Change are not stored until they are explicitly saved. To save changes in the class-hierarchy simply select the Save button. This will perform checks and inform about any issues that were encountered. Afterwards a dialog asks whether the changes shall be saved. Select Yes to save the changes. After saving the library close the class-hierarchy dialog by selecting Close.

When closing the class-hierarchy dialog via the Close button you also get the option to save or discard any changes after the dialog is closed.

Specify Hello World Model Type

Creating and configuring model types is handled through the Modi library attribute. Library attributes are accessible through the Library settings dialog. If it has been accidentally closed, then it can be opened again by following the steps:

1. Select the Library management component in the Development Toolkit.
2. Select Libraries -> Settings... in the menu or the Settings icon in the quick access bar.

To specify the model type:

1. Open the "Hello World" library if necessary by selecting the icon next to it and select the "Hello World (Dynamic)" library.
2. Select the Library attributes... button.
3. Select the Add-ons tab.
4. Set the value of the Modi attribute to:

   GENERAL order-of-classes:custom
   
   MODELTYPE "Hello World"
   INCL "Hello"
   INCL "World"
   INCL "HelloAnything"

5. Select Apply at the bottom.
6. When prompted whether the changed attribute values should be saved confirm with Yes.

Check the Result

The result from the changes to the library can be now used in the Modelling Toolkit. However, to see the result in the Modelling Toolkit it is first necessary to create an ADOxx user which has the library assigned.

Create Hello World User

To create a user for testing the Hello World library perform these steps in the Development Toolkit:

1. If the Library management dialog is still open, then close it by selecting Close.
2. Select the User management component.
3. Select User -> User list... in the menu or the User list icon in the quick access bar to open the User management - User list window.
4. Select Add... to create a new user.
5. Enter hello for the User name, Password and Confirm password.
6. For the Application library select Hello World.
7. Select the User group... button on the right side.
8. Clicking the small icon to the left of the ADOxx user group. It should show an icon with a small green checkmark.
9. Confirm all the windows to close them (OK, Add, Close, Close).

Every ADOxx user is assigned to one specific Application Library which is loaded when logging into the Modelling Toolkit.

Create a Hello World Model

After a user has been created and assigned to the library the first Hello World model can be created by:

1. Start the Modelling Toolkit and log in the User name hello and Password also hello.
2. Select Model -> New... in the menu.
3. Enter the details for the new model:
   • Select Hello World for the Model type.
   • Enter Hello World Model for the Name.
   • Select the Models item in the Model group list.
4. Select Create.

Add Objects to Model

To add Hello and World objects and HelloAnything relations to the model follow the steps in the Modelling Toolkit:

1. If the model is not yet opened, then open the model by double clicking on its name in the Explorer.
2. Select in the Modelling bar a class for which to create objects.
3. Click on the drawing area to create an object at the position.
   • An object is created for each click until the right mouse button is selected.
   • For relations / connectors first select the source object of the connector and then the target object.
4. Switch to a different class in the Modelling bar and repeat step 3.
5. Right-click or select the mouse-cursor icon in the Modelling bar to switch back to Edit mode, where existing objects can be moved, edited etc.

Where to Continue

The documentation is mainly structured to be read in the order of pages in the list on the left. There are however some pages that could be focused on:

• Check the ADOxx Development Environment and ADOxx Low-Code support for some tools that can help with developing your modelling tool.
• Read some basics about the ADOxx platform in the introduction chapter, the user interface and Notebooks.
• Afterwards the chapter for Modelling Language Implementation introduces the relevant concepts for realizing a modelling language with basic functionalities provided by the platform.
  • The pages for the AttrRep Language and GraphRep Language provide a reference for various details used in specific parts.
• To take things a step further the chapter about Mechanisms and Algorithms Implementation provides information on how to realize custom functionalities tailored to your modelling language.
  • Here also the AdoScript reference, MessagePort reference and Event reference become useful as a source for looking up specifics.
• Once you have finished configuring your library you can create your own modelling tool by following the packaging procedure

The chapters for ADOxx Components, ADOxx Development Languages, Special Cases and Troubleshooting are more of a reference guide to check specific details on those topics. The same is true for the AdoScript Reference.