OSF DCE Application Development Guide--Core Components

OSF DCE Application Development Guide—Core Components

28.4.1 Deﬁning an Attribute Trigger/Attribute Association

When an attribute is created with the sec_rgy_attr_update( ) call, you deﬁne the

association between the attribute type and an attribute trigger by specifying the

following:

• Trigger Type

Deﬁnes the trigger as a query server (invoked for query operations) or an update

server (invoked for updates operations). The trigger type is deﬁned in a

sec_attr_trig_type_t data type, which is used by a sec_attr_schema_entry_t data

type.

• Trigger Binding

Deﬁnes the server binding handle for the attribute trigger. The details of the trigger

binding are deﬁned in a number of data types, which are also used by the

sec_attr_schema_entry_t data type. Trigger binding is described in detail in

Section 28.1.3.7.

Only if both of pieces of information are provided will the association between the

attribute type and the attribute trigger be created. You can associate an attribute trigger

to any attribute type of any encoding except for attribute sets.

28.4.1.1 Query Triggers

When you execute a call that accesses an attribute associated with a query trigger, the

client-side attribute lookup code performs the following tasks:

• Binds to the attribute trigger (using a binding from the attribute type’s schema entry)

• Makes the remote sec_attr_trig_query( ) call to the attribute trigger server, passing

in the attribute keys and optional information provided by the caller

• If the sec_attr_trig_query() call is successful, returns the output attribute(s) to the

caller

If you execute a sec_rgy_attr( ) update call with an attribute type that is associated with

a query trigger, not an update trigger, the input attribute values is ignored and a ‘‘stub’’

attribute instance is created on the named object simply to mark the existence of this

attribute on the object. Modiﬁcations to the real attribute value must occur at the

attribute trigger.

28.4.1.2 Update Triggers

When you execute a call that accesses an attribute associated with an update trigger, the

client-side attribute update code performs the following tasks:

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