http://www.jason-grey.com web development, mobile, service oriented architecture, flex, flash, silverlight, ajax and so on. Wed, 27 May 2009 00:48:31 +0000 http://wordpress.org/?v=2.9.1 en hourly 1 http://www.jason-grey.com/2008/10/what-makes-a-good-componentservice/ http://www.jason-grey.com/2008/10/what-makes-a-good-componentservice/#comments Wed, 01 Oct 2008 15:46:54 +0000 jg http://www.jason-grey.com/?p=23 A few collected thoughts & notes from around the web regarding what makes a good component/service.

• Interface – all implementations share this. Should have few methods, use data objects as return values, take primitives as inputs, throw only custom exceptions, and be very, very well documented.
• Implementations – implement the logic behind the service. May provide extra features such as caching, or such things as optional collaborations.
• Data – data objects this service deals with. Should be immutable, comparable, cloneable as much as is possible. Should be serializable/XML/Persistance annotated in most languages.
• Storage – Data (or data.io) package should define storage API, and an in-memory data store. Allow other services/projects/subprojects to define database backed or other kinds of data stores.
• Cache – Data.Cache packages should define cache API? (or can this be standard per runtime?) Who should be in charge of caching? The service itself, or the user of the service?
• Use dependency injection for all services/data stores it requires. Use constructor-injection as much as possible.
• Throw errors early – in constructor if possible.
• Exceptions – custom exceptions for high level categories of erroneous behavior (try not to do one for every possible condition – classify, and wrap). Don’t re-throw exceptions from other frameworks – wrap in custom exception.
• Make behavior configurable via dep injection as much as possible. Use filters or strategies.
• Inject 1 configuration object instead of many options. Standardize on configuration API/Framework for each runtime/language.
• Standardize on logging framework/API for each runtime/language, and make sure it’s used (instead of System.out or simliar)
• Provide events/messages and/or hooks for important happenings so others can do things pre/post.

]]> http://www.jason-grey.com/2008/10/what-makes-a-good-componentservice/feed/ 0 http://www.jason-grey.com/2006/03/check-out-google-base/ http://www.jason-grey.com/2006/03/check-out-google-base/#comments Sun, 05 Mar 2006 02:44:52 +0000 jg http://www.jason-grey.com/2006/03/04/check-out-google-base/ Google’s got another great beta out there – Google Base. It’s a place for you to post your own content. They take it a step further by allowing you to define (or use predefined) content types. Each content type has a set of attributes. Then, custom search interfaces are provided against the content types, for example, see recipes. Doesn’t seem like there’s an API out there yet, so I think this is of limited use for now.

]]> http://www.jason-grey.com/2006/03/check-out-google-base/feed/ 0