Most applications that go beyond simple exercises are too complex to start developing them from the start; a model that describes the entities in the application domain and their relations is needed. To fully support such a domain-driven development, we need three things:
- A graphical tool for model design and import/export of the model definitions; this is the Model Concepts tool
- A domain model framework—Dartlero for simple cases and Dartling for more complicated business domains
- A web component framework for rapid development of dynamic web applications: the
Polymer.dartpackage
The first two were developed by Dzenan Ridjanovic, one of the authors, and the third was developed by the Google Dart team. All are written in Dart and are available as free, open source software. The remainder of this chapter will show how to use model concepts and Dartlero, and we will apply them in constructing a simple model of categories and links. Web components, which are essentially chunks of reusable HTML5, are explained in Chapter 8, Developing Business Applications with Polymer Web Components. We will also build a web component application for the category-links model. Dartling is discussed in depth in Chapter 9, Modeling More Complex Applications with Dartling. Both of them will be used in the projects from Chapter 10, MVC Web and UI Frameworks in Dart – An Overview, onwards. First we will explore the model concepts.