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Assumed Scopes

   

CDF Version 1 did not allow the scope of an attribute to be explicitly declared. This led to ambiguities in the interpretation of attribute entries in the toolkit programs and user applications. CDF Version 2 does allow the scope of an attribute to be declared when the attribute is created. To ease the transition from Version 1 to Version 2, CDF distributions prior to CDF V2.5 contained the notion of assumed attribute scopes. Assumed attribute scopes   arose when the CDF library had to guess the scope of an attribute in a Version 1 CDF (e.g., when the CDFconvert program converted a Version 1 CDF to a Version 2 CDF). Beginning with CDF V2.5, all assumed attribute scopes are converted   to the corresponding definite scope. When a CDF is read this conversion occurs only in the CDF library --- the CDF is not physically altered. When an existing CDF is written to, each assumed attribute scope detected will be physically converted to the corresponding definite scope. Note that if this automatic conversion is incorrect, the scope of an attribute can be corrected   using the Internal Interface in an application program or by editing the CDF with the CDFedit program.



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