Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

New Filter API in Vaadin 6.6

DZone's Guide to

New Filter API in Vaadin 6.6

· Java Zone
Free Resource

Get the Edge with a Professional Java IDE. 30-day free trial.

Vaadin is available in version 6.6 preview since this week. Among other interesting enhancements, one surely caught my attention, the new Filter API.

To understand why it's so interesting, one must know how it's handled in version 6.5 and before. But first, a word about filters in Vaadin: they are used in containers, which handle collections of items, in order to sort out eligible items. The Container.Filterable interface define a method to add a single filter, whose signature is:

 

addContainerFilter(Object propertyId, String filterString, boolean ignoreCase, boolean onlyMatchPrefix)

So, we can only filter on string equality, and this equality can be loosened/tightened toward case and position. Morevoer, filters on the same property are additive. If you need to go beyond that, your goose is cooked. In a previous proposal to a request, the filter had to be accent insensitive, which is not supported. I had to hack like mad to implement it. In effect, since most of the container API's code is private, I copied it to offer the needed option alternative. It did the trick but it's pretty dirty.

However, the new API supplies a true extensible model for filters which renders my previous development obsolete. Facts worth mentioning are the following:

  • The Container.Filterable interface becomes Container.SimpleFilterable, with no other changes in the method signatures
  • A brand-new Container.Filterable is added, with the method:
addContainerFilter(Container.Filter filter)
  • The Filter interface becomes public, and brings an entire hierarchy, with boolean composition in mind (meaning you can OR, AND or NOT you filters in combination). The interface has two methods:
appliesToProperty(Object propertyId) passesFilter(Object itemId, Item item)

These updates make creating an accent-insensitive a breeze. Conclusion is, if you're interested in Vaadin, you have to take a look at the new version, if only for the filter API!

To go further:

  • Vaadin 6.6.0 pre1 is available here
From http://blog.frankel.ch/new-filter-api-in-vaadin-6-6

Get the Java IDE that understands code & makes developing enjoyable. Level up your code with IntelliJ IDEA. Download the free trial.

Topics:

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}