About Modelica Components

A Modelica component is an instance of a Modelica class.

This page discusses:

See Also
About Dymola Behavior Modeling
Working with the Component Browser

About Components

A component is an instance of a class. Its parameter values can be changed.

Components appear in the Component Browser, and in the diagram layer.

About Replaceable Components

In a replaceable component, you can redeclare:

  • an inherited class
  • a class of its subcomponents.

See Working with Replaceable Components

Modelica Text

In Modelica, a replaceable component is declared in the following way: 

class C1
replaceable MyClass M1;
end C1;

The component can be replaced either in another class that extends C1: 

class C2
extends C1(redeclareMyOtherClass M1);
end C2;

or by creating a component from C1: 

class C2
C1 c1comp(redeclare MyOtherClass M1);
end C2;

When replaced, M1 attributes are modified in both C1 and C2. Note that you can edit only components that have a graphical representation.

It is also possible to set constraints on which the class of the replaceable component can be replaced with:

class C3
replaceable MyClass M1 constrainedby MySpecialClass;
 
end C3;

For more information about the capabilities and attributes of replaceable and replaced components, see the Modelica Language Specification, available at http://www.modelica.org.