LINK="#0000bb"  VLINK="#551a8b" ALINK="#ff0000">

<H3>
Objects of the <STRONG>base.Asn1Object</STRONG> class
</H3>

<P>
Instances of <A HREF="base.html#Asn1Object">base.Asn1Object</A> use
a set of instance variables for controlling ASN.1 object properties,
each of which falls into one of the following categories:
</P>

<P>
ASN.1 object tagging
</P>

<A NAME="tagClass"></A>
<DL>
<DT><STRONG>tagClass</STRONG></DT>
<DD>
<P>
This instance variable should be initialized to ASN.1 object class identifier
(integer). Possible values held in <A HREF="base.html#tagClasses">
tagClasses</A> dictionary.
</P>
<P>
The default value for <STRONG>tagClass</STRONG> is
tagClasses['UNIVERSAL'].
</P>
</DD>
</DL>

<A NAME="tagFormat"></A>
<DL>
<DT><STRONG>tagFormat</STRONG></DT>
<DD>
<P>
This instance variable should be initialized to ASN.1 object format identifier
(integer). Possible values held in <A HREF="base.html#tagFormats">
tagFormats</A> dictionary.
</P>
</DD>
</DL>

<A NAME="tagId"></A>
<DL>
<DT><STRONG>tagId</STRONG></DT>
<DD>
<P>
This instance variable should be initialized to ASN.1 object tag (integer).
</P>
</DD>
</DL>

<A NAME="tagCategory"></A>
<DL>
<DT><STRONG>tagCategory</STRONG></DT>
<DD>
<P>
This instance variable should be initialized to ASN.1 object tagging method
identifier (integer). Possible values held in
<A HREF="base.html#tagCategories">tagCategories</A> dictionary.
</P>
<P>
The default value for <STRONG>tagCategory</STRONG> is
tagCategories['IMPLICIT'].
</P>
</DD>
</DL>

<P>
ASN.1 object initializer verification
</P>

<A NAME="allowedTypes"></A>
<DL>
<DT><STRONG>allowedTypes</STRONG></DT>
<DD>
<P>
This instance variable should be initialized to a list of Python types allowed
for loading into ASN.1 object.
</P>
</DD>
</DL>

<P>
ASN.1 subtyping
</P>

<P>
The ASN.1 standard specifies a method of deriving a subtype by restricting
the set of values defined for a parent type. Six different forms of notations
for restricting the value set of a subtype are provided in the standard. The
following instance variables can be used for specifying these subtyping
constraints:
</P>

<A NAME="singleValueConstraint"></A>
<DL>
<DT><STRONG>singleValueConstraint</STRONG></DT>
<DD>
<P>
This instance variable can be initialized to a list of ASN.1 object-specific
set of values that the subtype may take on.
</P>
<P>
For example, for a numeric object: singleValueConstraint = [1, 3, 5]
</P>
</DD>
</DL>

<A NAME="containedSubtypeConstraint"></A>
<DL>
<DT><STRONG>containedSubtypeConstraint</STRONG></DT>
<DD>
<P>
This instance variable can be initialized to a list of ASN.1 object-specific
set of values of the subtypes that this object contains.
</P>
</DD>
</DL>

<A NAME="valueRangeConstraint"></A>
<DL>
<DT><STRONG>valueRangeConstraint</STRONG></DT>
<DD>
<P>
This instance variable can be initialized to a tuple of numerical values of
the endponts of the range that this ASN.1 object may take.
</P>
<P>
For example, for a numeric object: valueRangeConstraint = (0, 65535)
</P>
</DD>
</DL>

<A NAME="sizeConstraint"></A>
<DL>
<DT><STRONG>sizeConstraint</STRONG></DT>
<DD>
<P>
This instance variable can be initialized to a tuple of numerical values of
the number of items in a type that ASN.1 object may take.
</P>
<P>
For example, for a structured object that takes from one to 16 components:
sizeConstraint = (1, 16)
</P>
</DD>
</DL>

<A NAME="permittedAlphabetConstraint"></A>
<DL>
<DT><STRONG>permittedAlphabetConstraint</STRONG></DT>
<DD>
<P>
This instance variable can be initialized to a list of all values that can be
constructed using the sub-alphabet of the parent ASN.1 object type.
</P>
<P>
For example, for a string object that implements telephone tone buttons,
permittedAlphabetConstraint = [ '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9'].
</P>
</DD>
</DL>

<A NAME="innerSubtypeConstraint"></A>
<DL>
<DT><STRONG>innerSubtypeConstraint</STRONG></DT>
<DD>
<P>
This is not yet implemented.
</P>
</DD>
</DL>

<HR>

<ADDRESS>
ilya@glas.net
</ADDRESS>