Subject Keywords are used to implement categorization for the Content Management system. A Subject Keyword is a small label, such as "Oracle Documentation" or "My Favorite Foods", which can be associated with any number of content items. Thus, content items may be grouped by arbitrary categories. For example, assigning the Subject Keyword "My Favorite Foods" to the content items "Potstickers", "Strawberries" and "Ice Cream" would indicate that all the three items belong in the same category - namely, the category of the user's favorite foods. The actual physical location of these items within the repository is irrelevant.
Subject Keywords may be nested to provide more detailed control over categorization; for example, "My Favorite Foods" may be further subdivided into "Healthy" and "Unhealthy". Subject Keywords which have descendants are referred to as "Subject Categories".
The content_keyword object type is used to represent Subject Keywords (see content_keyword.sql) The content_keyword type inherits from acs_object:
acs_object_type.create_type ( supertype => 'acs_object', object_type => 'content_keyword', pretty_name => 'Content Keyword', pretty_plural => 'Content Keywords', table_name => 'cr_keywords', id_column => 'keyword_id', name_method => 'acs_object.default_name' );In addition, the cr_keywords table (see content-create.sql) contains extended attributes of Subject Keywords:
create table cr_keywords (
keyword_id integer
constraint cr_keywords_pk
primary key,
heading varchar2(600)
constraint cr_keywords_name_nil
not null,
description varchar2(4000)
);
In content-keyword.sql:
attr_id := acs_attribute.create_attribute ( object_type => 'acs_object', attribute_name => 'heading', datatype => 'string', pretty_name => 'Heading', pretty_plural => 'Headings' ); attr_id := acs_attribute.create_attribute ( object_type => 'content_keyword', attribute_name => 'description', datatype => 'string', pretty_name => 'Description', pretty_plural => 'Descriptions' );
Thus, each Subject Keyword has a heading, which is a user-readable heading for the keyword, and a description, which is a somewhat longer description of the keyword.
The cr_item_keyword_map table (see content-create.sql) is used to relate content items to keywords:
create table cr_item_keyword_map (
item_id integer
constraint cr_item_keyword_map_item_fk
references cr_items
constraint cr_item_keyword_map_item_nil
not null,
keyword_id integer
constraint cr_item_keyword_map_kw_fk
references cr_keywords
constraint cr_item_keyword_map_kw_nil
not null
constraint cr_item_keyword_map_pk
primary key (item_id, keyword_id)
);
The API used to access and modify content keywords are outlined below. The function names are links that will take you to a more detailed description of the function and its parameters.
| Function/Procedure | Purpose | Description |
|---|---|---|
| new | Create a new Subject Keyword | This is a standard new function, used to create a new Subject Keyword. If the parent id is specified, the new keyword becomes a child of the parent keyword (which may now be called a Subject Category) |
| delete | Delete a Subject Keyword | This is a standard delete function, used to delete a Subject Keyword |
|
get_heading set_heading get_description set_description |
Manipulate properties of the Keyword | You must use these functions to manipulate the properties of a keyword. In the future, the data model will be updated to handle internatiolization, but the API will not change. |
|
item_assign item_unassign is_assigned |
Assign Keywords to Items | These functions should be used to assign Subject Keywords to content items, to unassign
keywords from items, and to determine whether a particular keyword is assigned to an
item. The is_assigned function can be used to determine if a keyword matches a content item, based on the recurse parameter:
|