CayenneObjectManager - alternative API for using Apache Cayenne
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Key: CAY-988
URL: https://issues.apache.org/cayenne/browse/CAY-988
Project: Cayenne
Issue Type: Improvement
Affects Versions: 3.0
Reporter: David Marko
Assignee: Andrus Adamchik
Priority: Trivial
Hello,
a few months ago a wrote about creating alternative approach to using Apache Cayenne. Actualy I use Cayenne with Click Framework and following scenario came from pratice on several projects. The main idea is to use Cayenne as very stable background(engine) but alter API to something closer to ActiveRecord like approach. The result is CayenneObjectManager that implementes alternative API that, as result, generate standard Cayenne queries.
CayenneObjectManager API assumes Java5 as generics are used extensively and is tested with latest Apache Cayenne M3. Entire package is rather small and is intended to be extended by other methods. I'm not very experienced JAVA developer so one thing I would like to ask is, if someone can review the concept and correct some potencial mistakes or contribute with some ideas etc. I'm open for correction.
David
For quick example just image you have a simple table with Role names and imagine how simply you can work with this.
// Load role object by its name
COManager manager=new COManagerImpl();
// init is based on usage scenario. This can be used in standalone app. for e.g. web app usage, the context is inititalized automaticly from DataContext.getThreadDataContext();
co_manager.setContext(DataContext.createDataContext());
Role role_admin=co_manager.find(Role.class).byProperty("name").EQUALS("admin").first();
// all roles from allowed list as key-pair for checkbox field
Map<String,String> roles=co_manager.find(Role.class).byProperty(Role.NAME_PROPERTY).IN(allowed_roles).to_pairs("name", "id");
CayenneObjectsManager - alternative API for working with Apache Cayenne subsystem
// Available use cases
// find one item by ID
co_manager.find(Class).byId(id)
// find all items by property and given condition
co_manager.find(Class).byProperty("property").EQUALS(value)
// find first item by property and given condition
co_manager.find(Class).byProperty("property").BETWEEN(value1,value2).first()
co_manager.find(Class).byProperty("property").LIKE(value).first()
co_manager.find(Class).byProperty("property").IN(range).first()
// find all items
co_manager.find(Class).all()
// find all items by based on CayenneObjectsQuery
co_manager.find(Class).allByQuery(COQuery query)
// find all firts item by based on CayenneObjectsQuery
co_manager.find(Class).allByQuery(COQuery query).firts()
//find all selected items as key-pairs available e.g. for checkbox field
co_manager.find(Class).byProperty("property").EQUAL(value1).to_pairs(key,value)
// aggregate functions
co_manager.aggregate(Class).count("property")
co_manager.aggregate(Class).count("property", COQuery query)
co_manager.aggregate(Class).sum("property")
co_manager.aggregate(Class).sum("property", COQuery query)
co_manager.aggregate(Class).avg("property")
co_manager.aggregate(Class).avg("property", COQuery query)
co_manager.aggregate(Class).count("property", Query.where("year >$year").addParam("year", 2003));
// common actions
co_manager.create(Class)
co_manager.save()
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