Ports

Ports are used in flowchart blocks as interface points for the agent flow mechanism. Agents are sent and received through ports. The ways of sending agents (entities) through ports are described here.

To create a port

1. Drag the Port element from the Agent palette onto the diagram of agent.

General

Name — The name of the port. The name is used to identify and access the port from code.

Show name — If selected, the port name is displayed on a presentation diagram.

Ignore — If selected, the port is excluded from the model.

Visible on upper agent — If selected, the port is also visible on the upper agent where this agent lives.

Visible — If selected, the port is visible on a presentation at runtime.

Message handling actions

These properties are visible only if the Library Developer Mode is switched on.

On receive — [Visible if the advanced option Custom port is not selected] The code executed each time a message is received by the port (when the user calls the method receive() of the port, or when this port receives a message from a port of some embedded object). Here you can access just received message as msg (local variable of type Object).*

On send — [Visible if the advanced option Custom port is not selected] The code executed each time a message is sent by the port (when the user calls the method send() of the port, or when this port relays message received "from outside" (i.e. from a port of agent located on the same or higher level in the model hierarchy)). Here you can access the message as msg (local variable of type Object).*

* If the field is left blank, or true is returned, the message is processed further as defined by message routing rules, otherwise it is discarded.

Advanced

These properties are visible only if the Library Developer Mode is switched on.

Custom port — If selected, the port will be an instance of the custom port class specified in the Constructor code. This is needed, when you have a number of ports with the same custom functionality (e.g. the same On receive message handler) in your model, and you want to define this functionality once in a custom port class and then simply use instances of that port class.

In message type — [Enabled if the Custom port option is not selected] The type of messages that are allowed to be received by the port. If you leave Object here, message type checking will not be performed and all messages will be allowed to be received.

Out message type — [Enabled if the Custom port option is not selected] The type of messages that are allowed to be sent by the port. If you leave Object here, message type checking will not be performed and all messages will be allowed to be sent.

Constructor code — [Visible if the Custom port option is selected] Here you can type the constructor of the created port class, e.g. MyPort(this)

You can customize the port behavior by writing your own code in On send and On receive port properties. However, if the defined port functionality is frequently needed, defining your own port class is preferable. Thus, instead of writing the same code for all the port instances in your model, you need just to create new port class once and specify this class as the port class for the ports you need. Create your own port class as a new Java class, or in a library. Defining port class in a library has an advantage of future reuse of your custom ports in other models as well.

To define a custom port class

1. In the Projects view, right-click (macOS: Ctrl + click) the model item, and choose New > Java Class… from the popup menu.
2. The New Java Class dialog box is displayed.
3. Specify the name of the new class in the Name edit box.
4. Specify the name of the base class. Type in Superclass edit box. Port class is the base class for all port classes in AnyLogic. This class provides basic port functionality and if you want to customize the default behavior of ports, you need to derive your own port classes from Port class.
5. Click Finish to complete the process.
6. You will see that the code editor for the just created class is opened. Write there code for your port. Here you can override some functions of the base class Port. When finished, you can use this class as a port class for any port instances in your model.

To set the created class as a port class for a port instance

1. Select the port in the graphical editor.
2. In the Advanced section of the Properties view, select the Custom port check box.
3. In the Constructor code field, type the constructor of the created port class, e.g. MyPort(this)

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