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By Pete Su, Michael Yoon, Richard Li, Rafael Schloming
+Before OpenACS 4, software developers writing OpenACS applications or modules would develop each data model separately. However, many applications built on OpenACS share certain characteristics or require certain common services. @@ -32,7 +32,7 @@ object type (e.g. users) to instances of another object type (e.g. groups).
The next section will explore these facilities in the context of the the -particular programming idioms that we wish to generalize.
Related Links
This design document should be read along with the design documents for the new groups system, subsites and the permissions system
The motivation for most of the facilities in the OpenACS 4 Object Model can be +particular programming idioms that we wish to generalize.
Related Links
This design document should be read along with the design documents for the new groups system, subsites and the permissions system
The motivation for most of the facilities in the OpenACS 4 Object Model can be understood in the context of the 3.x code base and the kinds of programming idioms that evolved there. These are listed and discussed below.
Object identification is a central mechanism in OpenACS 4. Every application object in OpenACS 4 has a unique ID which is mapped to a row in a central table @@ -99,9 +99,9 @@ user X perform action Y on object Z", the OpenACS security model will defer to an object's context if there is no information about user X's permission to perform action Y on object Z.
The context system forms the basis for the rest of the OpenACS access control -system, which is described in in two separate documents: one for the permissions system and another for the -party groups system. The context system -is also used to implement subsites.
As mentioned above, many OpenACS modules provide extensible data models, and +system, which is described in in two separate documents: one for the permissions system and another for the +party groups system. The context system +is also used to implement subsites.
As mentioned above, many OpenACS modules provide extensible data models, and need to use application specific mechanisms to keep track of user defined attributes and to map application data to these attributes. In the past, modules either used user/groups or their own ad hoc data model to provide @@ -444,7 +444,7 @@ the knowledge level data model to create, manage, query and manipulate objects in a uniform manner. The acs_rels table has an analogous role in storing information on relations.
These are all the tables that we'll discuss in this document. The rest -of the Kernel data model is described in the documents for subsites, the permissions system and for the groups system.
Some examples of how these tables are used in the system can be found in +of the Kernel data model is described in the documents for subsites, the permissions system and for the groups system.
Some examples of how these tables are used in the system can be found in the discussion of the API, which comes next.
Now we'll examine each piece of the API in detail. Bear in mind that the Object Model API is defined primarily through PL/SQL packages.
The object system provides an API for creating new object types and then attaching attributes to them. The procedures create_type and @@ -567,7 +567,7 @@ automatically be hooked into every generic object service that exists. Better still, this code need not be changed as new services are added. As an aside, the most important service that requires you to subtype -acs_object is permissions.
The next important piece of the API is defined in the +acs_object is permissions.
The next important piece of the API is defined in the acs_object package, and is concerned with creating and managing objects. This part of the API is designed to take care of the mundane bookkeeping needed to create objects and query their attributes. @@ -857,4 +857,4 @@ on par with the old user/groups system in a more general way.
Pete Su generated this document from material culled from other documents by Michael Yoon, Richard Li and Rafael Schloming. But, any remaining lies are his and his alone.