TagOperation¶

class tracdap.rt.metadata.TagOperation¶

Bases: enum.Enum

Enumeration of available TagUpdate operations.

See also

APPEND_ATTR = 4¶

Append one or more values to an existing attribute, fail if the attribute does not exist.

The existing attribute may be single- or multi-valued and the append operation may add one value or multiple values (i.e. all combinations are permitted). The appended value(s) must be of the same basic type as the existing value(s).

CLEAR_ALL_ATTR = 6¶

Remove all the attributes from a tag.

This operation does not affect controlled attributes, which are still managed by TRAC according to its normal rules.

CREATE_ATTR = 2¶: Add an attribute to a tag, fail if the attribute already exists.

CREATE_OR_APPEND_ATTR = 1¶

Add an attribute to a tag or append to it if it already exists.

If the attribute does not exist it will be created using CREATE_ATTR, otherwise it will appended to using APPEND_ATTR.

See also

TagOperation.CREATE_ATTR, TagOperation.APPEND_ATTR

CREATE_OR_REPLACE_ATTR = 0¶

Add an attribute to a tag or replace it if it already exists.

This is the default operation if no operation is specified. If the attribute does not exist it will be created using CREATE_ATTR, otherwise it will replaced using REPLACE_ATTR.

See also

TagOperation.CREATE_ATTR, TagOperation.REPLACE_ATTR

DELETE_ATTR = 5¶: Remove an attribute from a tag, fail if the attribute does not exist.

REPLACE_ATTR = 3¶

Replace an attribute on a tag, fail if the attribute does not exist.

When replacing an attribute, the new attribute must be of the same basic type as the old one. It is allowed to replace a single-valued attribute with a multi-valued one and vice-versa (this is not considered to be changing the basic type).

Changing the type of attributes is not recommended because it is likely to confuse applications that refer to those attributes. If you really need to change the type of an attribute (e.g. to correct an error), use DELETE_ATTR followed by CREATE_ATTR.