Frequently Asked Questions

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Frequently Asked Questions

What is Metawidget?
Who makes Metawidget?
What are the goals of Metawidget?
What are Metawidget's system requirements?
Why is it called Metawidget?
Why is (some feature) of Metawidget implemented the way it is?
Who uses Metawidget?
Is Metawidget (yet) another Web application framework?
How does Metawidget compare to Swing/Java Server Faces/Hibernate/(some other framework)?
Who are Metawidget's competitors?
Is an OIM like an ORM?
Is Metawidget mature?

What is Metawidget?

Metawidget is an object/user interface mapping tool. The term object/user interface mapping (OIM) refers to the technique of inspecting objects, at runtime, and creating User Interface (UI) widgets.

As much as possible, Metawidget does this without introducing new technologies. Metawidget inspects an application's existing back-end architecture and creates widgets native to its existing front-end framework.

Who makes Metawidget?

Metawidget is an Open Source project licensed under the LGPL. It is developed by the community. It was started by Richard Kennard of Kennard Consulting.

What are the goals of Metawidget?

Metawidget continues the trend in recent years toward more POJO-centric development. This trend allows developers to rely on 'sensible defaults', writing as little 'boilerplate code' as possible. The Goals Of Metawidget are:

to create UI widgets by inspecting existing back-end architectures
not to try to 'own' the entire UI, but to focus on creating native sub-widgets for slotting into existing UIs
to perform inspection at runtime, detecting types and subtypes dynamically

Note it is not a goal of Metawidget that the widgets look the same on every UI framework: every UI has different features, and Metawidget takes advantage of this.

What are Metawidget's system requirements?

Metawidget requires at least J2SE 1.4, and varies depending on which optional modules you use.

Its annotation support requires at least Java SE 5. Its javax.swing.GroupLayout support requires at least Java SE 6.

Why is it called Metawidget?

The name has two meanings:

a 'widget' is the technical term for a Graphical User Interface component (such as a text box). A 'meta' widget is a widget composed of other widgets.
Metawidget is a widget built by metadata gathered from the back-end

Why is (some feature) of Metawidget implemented the way it is?

See the developer blogs for insights into, and to provide feedback on, Metawidget's development.

Who uses Metawidget?

As of v0.55, both the Java Server Faces Metawidget and the Swing Metawidget are deployed in production systems.

Is Metawidget (yet) another Web application framework?

No. Metawidget uses existing Web application frameworks, it does not compete with them.

How does Metawidget compare to Swing/Hibernate/(some other framework)?

Metawidget uses other frameworks, it does not compete with them.

Who are Metawidget's competitors?

There are many great projects that address automatic UI generation. However, we are not aware of any with the same goals as Metawidget:

Project	Differences to Metawidget
BeanView	Does not share goal 1: inspect existing back-end technologies (eg. introduces its own annotations)
Grails	Does not share goal 1: inspect existing back-end technologies (eg. requires Groovy and a `constraints` construct). Only shares goal 3 to a point: to tweak the output you run `grails install-templates` or `grails generate-views` which use static code generation
JMatter	Does not share goal 2: create native sub-widgets rather than 'owning' the entire UI
Merlin	Does not share goal 1: inspect existing back-end technologies using pluggable inspectors (eg. it expects a fixed-set of back-end technologies, for example they deprecated their @Alias annotation in favour of @org.jboss.seam.annotations.Name)
Naked Objects	Does not share goal 2: create native sub-widgets rather than 'owning' the entire UI
OpenXava	Does not share goal 2: create native sub-widgets rather than 'owning' the entire UI
Seam-Gen	Does not share goal 3: perform runtime UI generation, as opposed to static code generation
Wicket Web Beans	Does not share goal 2: slot into existing UIs (eg. Wicket only)

Is an OIM like an ORM?

Object Relational Mapping (ORM) technologies, such as Hibernate, are concerned with the back-end: mapping an Object (the O in ORM) to a Relational Database (the R in ORM). Object Interface Mapping (OIM) technologies, such as Metawidget, are concerned with the front-end: mapping an Object (the O in OIM) to a User Interface framework (the I in OIM).

OIMs and ORMs are complementary and meet in the middle: they share the same O. By using an OIM in conjunction with an ORM, developers can significantly reduce the amount of code required for an application.