Re: Embedding into HTML [was signature/encryption tags]

David C. Martin (dcmartin@library.ucsf.edu)
Wed, 12 Apr 95 15:03:43 EDT

Check the URLs:

http://www.ckm.ucsf.edu/Papers/IEEE-VIS-94/
http://wira.ckm.ucsf.edu/Applets/Abstract.html
http://www.eolas.com/

dcm
--------isr.harvard.edu

Dianne Hackborn writes:

Just as some background, I am currently doing some research on including
programs with HTML documents. I've been reading this list for almost a
month now, trying to get an idea of how SGML/HTML tags should be
structured, and how the various little things about content types and
stuff are handled.

One of the main things I am concerned with at this point is the issue of
actually embedding a program in a document, which seems to be closely
related to these comments about signatures:

On Tue, 11 Apr 1995, Craig Hubley wrote:

> 2. A signature can be considered similar to any other MIME type in that it
> is information that is
> - not directly human readable (i.e. must be generated/read by a program)
> - potentially quite large (i.e. with a large key it could be 100s of bytes
,
> and generally will expand as key sizes expand to potentially several K)
> - not of interest to all readers (i.e. as graphics are often 'turned off'
> by many readers, authentication/signatures are often of interest only
> to those who intend to act directly on the information in some binding
> way
> - not directly useful in processing other information on/in the page

Is this a good general set of rules to go by for what should and
shouldn't be included directly in an HTML document? My current
implementation uses a structure in which it adds a new major section at the
<HEAD> and <BODY> level, called the <INTERFACE>. This section is
currently defined as:

<!ELEMENT MODULE - O EMPTY>
<!ATTLIST MODULE NAME CDATA #IMPLIED
VERSION NUMBER #IMPLIED
URL %URL; #IMPLIED>

<!ELEMENT SOURCE - - RCDATA>

<!ELEMENT INTERFACE - - (MODULE* & SOURCE)>
<!ATTLIST INTERFACE LANGUAGE CDATA #REQUIRED>

So, it contains zero or more <MODULE> tags, which declare all the external
modules needed by the program, and <SOURCE>, whose content is the actual
script which will be executed. [A bit more detailed description of this is
at <http://www.cs.orst.edu/~hackbod/exechtml/>, which is anextremely
preliminary design, but it's something. :)]

>From reading this list, I know that having the program directly included in
the document is most likely Not A Good Idea, and I will definitely be
changing things so that in some way the main program can be retrieved from
an extern URL like the modules are. But is it -absolutely- a bad thing to
make it possible to have an embedded program? It seems that this case
wouldn't fall into the last two categories listed about -- it most likely
is of interest to all browsers, and it is directly useful for processing
the other information in the page.

Any comments about this would be greatly appreciated.

-----------------------------------------------------------------------------
Dianne Kyra Hackborn "I must become important to them, intertwined
hackbod@mail.cs.orst.edu with roots into them, or else I'd lose my false
Oregon State University and newfound sense of pride."
//www.cs.orst.edu/~hackbod/ -- The Residents