Sidre Attributes enable attaching metadata (strings and values) to Sidre Views to support queries (e.g., search for Views with a given attribute name), outputting data for a subset of Views to files, and other ways an application may need to selectively process Views in a Sidre DataStore hierarchy.
An Attribute is created with a string name and a default scalar or string value. A default value can be changed later as needed.
- Attribute objects can only be created and destroyed using DataStore methods. The Attribute constructor and destructor are private (see DataStore).
- Each Attribute has a unique name and integer identifier. Either can be used to retrieve it from the DataStore.
Each Sidre View inherits all Attributes contained in the DataStore at their default strings or values. Then, an application may explicitly set any Attribute on a View. The application may also query the value of a View Attribute, query whether the Attribute was explicitly set, or set the Attribute back to its default value. See View for more information about Views.
The Attribute interface includes the following operations:
- Retrieve the name and unique id of the Attribute object.
- Set the scalar or string value of an Attribute.
- Get the type of an Attribute’s scalar value.