Alfresco Share (share.war) is a web application that runs on the Java Platform. In a development environment it is usually deployed and run on top of Apache Tomcat. Share is built up of a main menu that leads to pages, which is similar to most other web applications that you might come across. However, there is one special page type called Dashboard that contains dashlets. A Dashboard page can be configured by the end-user, who can add, remove, and organize the dashlets on the page.
Share pages and dashlets are implemented with something called web scripts, which is basically REST-based APIs. These APIs are called Surf web scripts when you are dealing with Alfresco Share. There is also repository web scripts that are used to extend the repository web application (alfresco.war) with REST-based APIs. Surf Web Scripts are referred to as Presentation Web Scripts and the repository web scripts as Data Web Scripts.
Share web scripts, pages, and dashlets are implemented with a user interface (UI) development framework called Surf. This framework was originally developed by Alfresco, then donated to the Spring Source foundation, and finally brought back into Alfresco products. It provides a way of breaking a HTML page into re-usable component parts. Surf is built on top of the Spring Web MVC technology, which in turn uses the Spring Framework.
Developers can also add completely new pages and dashlets to the Share UI when content should be viewed or handled in a specific way. Sometimes it is also required to modify existing pages. To customize the Share UI developers use so called extension points, which are supported ways of injecting new custom code that should alter the functionality of the Share web application. For more information on extension points, see Share UI Extension Points.
The following picture gives an overview of the Alfresco Share application architecture, note that not all available extension points are illustrated in this picture:
Share gets the content that it should display in pages and dashlets by calling repository web scripts, which returns JSON or XML that can be incorporated into the presentation. The presentation is actually put together with two different kinds of JavaScript frameworks, Yahoo UI library (YUI) and Aikau, which is based on Dojo. An Aikau page is based on Surf but it makes page composition much easier than with pure Surf pages.
You can focus solely on Aikau if the only thing you are going to do is add new stuff to the Share UI. However, if you need to alter behavior of existing pages, then you might also need to get up to speed on the details of the Surf page model, as only the following has been converted to Aikau:
- Share Header Menu and Title (4.2)
- Live Search (5.0)
- Filtered Search Page (5.0)
- Search Management Page (5.0)
- Site Management Page (5.0)
- Analytics and Reporting Widgets (5.0)
- Document List prototype (5.0)
The following sections get into a bit more details around Surf pages and Aikau pages.