xml-dev - Re: XML and LDAP: Common APIs?

[tpassin@home.com]

Jeff Turner was thinking about LDAP -

> I was just thinking how similar the XML and LDAP data models are. LDAP
> gives you a tree, where each node can contain data -and- can act as a
> namespace for other nodes. This corresponds pretty closely to XML (or
> maybe SML).
>
> Has anyone explored the possibility of crossover APIs for accessing all
> these 'tree-like' data structures in a standardised way? I'd like to be
> able to traverse an LDAP directory with DOM or SAX. How about querying
> LDAP with an XPath expression, or a stylesheet? Going the other way, how
> about accessing an XML document with an API like Sun's JNDI? I see that
> Sun have got a DSML "service provider", but wouldn't it be possible to
> generalise this to access any well-formed XML?
>
> Since LDAP is usually layered on a database, doesn't LDAP provide a
> simple kind of XML Database? Has anyone tried to map XML directly into
> LDAP like this?

LDAP is, I think, defined in terms of asn.1.  There is no standard xml
encoding for asn.1 yet.
asn.1 syntax can express things that can't be expressed in a dtd - mostly
data types, enumerated values, and constraints.  Presumably, xml schemas
will be able to express everything that a set of asn.1 type assignments can,
although I don't know if that is for sure or not.  Various people are
looking at encoding asn.1 in xml.

Since a binary encoding of an asn.1 instance is nothing like xml, I assume
that you mean if you already had an asn.1 instance that had been parsed by
an asn.1 parser. It does look like you ought to be able to make that tree
look like an xml tree, in which case you might be able to do what you
suggest.

Here's a link to an asn.1 vendor - you can look at their tools.  Basically,
it seems that the tools produce C or Java structures that represent the
various defined types.  I'm not too clear what people usually do about
querying and so forth.

http://www.oss.com/products/products.html

Cheers,

Tom Passin