To customize the workflow in the Model Builder, you can use a Method Call or a Settings Form. However, these are associated with a specific MPH-file, and you may want to reuse them between sessions or share them with colleagues. To make this possible, you can create an add-in based on a Method Call, Settings Form, or a custom ribbon tab. Such add-ins can then be stored in a user-defined add-in library. In addition, COMSOL Multiphysics comes with built-in add-in libraries. For the add-ins in the built-in library, you can review their Application Builder settings, including forms and methods, to quickly learn how to build your own add-ins.

Creating an add-in is similar to creating an application, with a few differences. Add-ins do not have their own graphics window, but instead use the main Graphics window in the Model Builder. An add-in should preferably work, or give controlled error messages, for any type of model.

To create an add-in, start from a form that you have created in the Application Builder and click Add-in Definitions in the Home tab of the ribbon, as shown below.

Right-click the Add-in Definitions node in the application tree and select Form Definition.

The figure below shows the Settings window for the Form Definition. Here, you can type a Label for the add-in form as well as select which form to use for the add-in. The Label will be displayed in the user-defined add-in library. You can select whether the form should be displayed as a Settings form in the model tree or as a dialog. The Allow multiple settings forms checkbox is used to allow for more than one instance of the Settings form in the model tree. The Description is displayed in the add-in library and as a tooltip when choosing among add-ins in the ribbon.

Click the Add-in Definition node to see its Settings window, as shown below.

The Filename is the location of the add-in MPH-file in the user-defined add-in library. This location can be on a shared network drive if you wish to share the add-in with your colleagues. The Label will be displayed in the Add-in Libraries window. The Unique identifier is what identifies the add-in and is intended to be unique for any COMSOL Multiphysics session. The unique identifier is recommended to be in a format similar to <company name>.<Add-in name> ;for example, my_company.my_add-in. The Editing password will be applied to the created add-in and is different from the editing password that you can specify in the root node Settings window of the MPH-file used to create the add-in.

To create the add-in, which is a special type of MPH-file, click the Create Add-in button.

As an alternative to a Form Definition you can use a Ribbon Tab Definition to create one or more ribbon tabs with customized buttons (items) and menus. The figures below show the settings for an add-in that defines a custom ribbon tab with menus and buttons.

The figure below shows this custom ribbon tab after it has been added from the Add-in Libraries.