Goals
The main purpose of Aikau is to provide a library of widgets that can be easily assembled into a web application for accessing a SkyVault repository. The aim is not to replace Share but it was necessary to migrate away from its original implementation, which was based around the Surf paradigms of pages, templates, components and web scripts, towards a solution that provided for rapid development and customization.
While Share continues to be based primarily on the YUI library, Aikau is based around the Dojo library.
The main goals of Aikau are:
- Provide a library of fine-grained, decoupled widgets that completely encapsulate all of their function, styling and localization behaviour.
- To make it easy to unit test those widgets across multiple browsers.
- To reduce the complexity of Surf rendered pages by removing Page, Template and Component configurations and replacing them with pages defined by an easily customisable JSON model in the JavaScript controller of a single web script.
- To be able to dynamically build pages both for and within the running UI and render them without restarting any servers.
- To provide a foundation on which our business partners and customers can build their own solutions.
Building on previous work
Between versions 4.0 to 4.2 there were significant enhancements to the Surf framework and deliberate refactoring of logic from the FreeMarker template into the JavaScript controller of the Share web scripts. Improvements to page load performance were achieved by reducing HTTP requests through the following methods:
- Using MD5 checksums to allow browsers to safely cache resources indefinitely
- Dynamically aggregating JavaScript and CSS dependencies into fewer resources
- Encoding images directly into CSS files.
All of these features are leveraged in the improvements and this makes it easier to produce faster, more reliable pages, in less time for the SkyVault Share and the SkyVault in the Cloud web applications.
Zero build
An important enhancement is a zero build approach. Surf is able to dynamically analyse the JSON model that defines the page being rendered and resolve all JavaScript dependencies that are then compressed and written into a single JavaScript resource that simulates a built Dojo layer. Surf caches all the dependency relationships as it finds them so it never traverses a dependency path a second time. It also caches the individual layers it generates so although the very first page rendered after server start up can take a few seconds to render, subsequent page rendering is much faster.
Encapsulation
When you render a web you are normally expected to take care of the styling by using separately referenced CSS files. For example, you might import a theme style sheet for the framework that you are using.
In the updated UI framework, each widget can optionally define its own CSS resources, including the ability to specify different resources for different media types. If that widget is used on a page then Surf will automatically include those CSS resources within a single aggregated CSS resource loaded on the page. The same principle is applied to localization files so the use of a widget ensures that its National Language Support (NLS) properties automatically built into a JavaScript resource loaded on the page. Widgets can scope their message bundles to ensure that there are no collisions and the core message handling function is smart enough to work through all of the message scopes in a widgets ancestry to ensure that the most specific message is displayed.
Cross JavaScript library support
Although Share was originally built using YUI2, JQuery plugins have also been introduced and Share will not be restricted to using Dojo. The UI framework is designed to easily support widgets provided by other libraries and by design it is possible to swap out Dojo widgets for those provided by other libraries. A mechanism exists for wrapping our existing YUI2-centric widgets to that they can be referenced in the JSON model for the page. The Calendar of any Share Site uses a combination of the YUI2, JQuery and Dojo libraries.
Continued extensibility
One of Share's greatest strengths is its ability to be easily customized. This is something that has been enhanced over the last few releases. A significant improvement was to make it easier to customize the client-side widgets that are instantiated on each page by customizing the JavaScript controller of a Component's web script. It is also possible to customize the numerous fine-grained widgets that comprise a page or Component. Widgets can be reconfigured, added or removed easily and because the widgets are decoupled (such that they do not rely on the existence of other widgets) making changes will not cause any errors.
Aikau use in Share
The library of Aikau widgets continues to grow. The following Share components are already implemented using Aikau:
- Header
- Live Search
- Filtered Search Page
- Search Management Page
- Site Management Page
- Analytics and Reporting Widgets
- Page Creator
- Document List Prototype
Aikau GitHub project
Aikau is available as an open-source project on GitHub.
Aikau Tutorial
A comprehensive Aikau tutorial is available on GitHub.
Aikau widget library documentation
The documentation for the Aikau widget library can be found on the Developer web site.