Umlaut Technical Overview
2,096 bytes added
17:30, 6 February 2008
Services are Run
When the resolve action wants to actually execute services, it goes through each priority level, and asks the Collection for the Services at that priority level.
ServiceResponse data and generation==
Before talking about how the services generate data, we should talk about the data format of a [http://umlaut.rubyforge.org/api/classes/ServiceResponse.html ServiceResponse]. A ServiceResponse is basically a unit of information generated by a Service, generally for display somewhere on the link resolver menu page. For example, there might be a ServiceResponse representing a fulltext link, a help link, or an abstract. ServiceResponses almost always link out somewhere, along with providing other data for display.
The ServiceResponse entity has a few 'standard' properties (display_text, url, notes), but also a property, service_data, consisting of a serialized hash for holding arbitrary key/value information. Different service types might require different key/values here. The  operator on ServiceResponse conveniently allows you to store arbitrary key/value information in this property (and also access/set the 'built-in' properties). For appropriately loose coupling between data stored, service generating it, and view, we define some conventions for what key/value pairs
used for what purposes in each response type, in comments on [http://umlaut.rubyforge.org/api/classes/ServiceResponse.html ServiceResponse class definition].
So what do we mean by a 'service type'? The list of all valid service types is defined in the ServiceTypeValue table. Each ServiceTypeValue has a one-word internal identifier token (name), a display_name for user presentation, and optionally a display_name_pluralized (to over-ride standard Rails pluralization). The values in this table are initialized from db/orig_fixed_data/service_type_values.yml when you run rake umlautdb:load_initial_data. We intend the local implementer to be able to create locally defined ServiceTypeValues too, if necessary. ServiceTypeValue uses the acts_as_enumerated plug-in to conveniently allow the developer to refer to an individual ServiceTypeValue by name: ServiceTypeValue[:fulltext] ==> the ServiceTypeValue object with name
'fulltext'. acts_as_plugin does efficient caching.
← Older edit
Newer edit →
Retrieved from "