The ReadOnly property of the PointAttributes collection is a Boolean indicating whether or not the program can change the values of attributes within the collection. The property is initially set to true indicating that members of the collection can not have their values changed. A program may set this property to false to allow modification of the contained PointAttribute object values.
This property is provided to prevent inadvertent modification of point attributes. In typical use, a program should only set this property to false when modification of PointAttribute values is required and then reset it to true when changes are complete.
The object placeholder is an object expression that evaluates to a PointAttributes collection.
Modification of PointAttribute object values from the collection change not only the local object but the stored server value as well. While setting the ReadOnly property is required to modify the values of the contained objects changes made to the server are still subject to the security restrictions configured for points, attribute sets, and point classes on the particular server for the logged in user.
Resetting this property to true after making modifications is recommended. The property affects all references to a particular PointAttributes collection within a program. In addition, for efficiency, the PI-SDK may cache PointAttribute collections once fetched. A program obtaining a PointAttributes collection and setting this property to false, then releasing the object may find, on obtaining the same collection later, that the ReadOnly property remains as last set. The ReadOnly property is only initialized to true before the first reference to the particular collection.