Subject: Re: status. Re: X11 BROWSER for WWW
From: timbl (Tim Berners-Lee)
To: [email-masked], www-talk
Date: Tue, 29 Oct 91 10:03:11 GMT+0100

Dan,

> I've made some tangible progress on the X11 browser, so I though 

> I'd let you know.
> ...
> This code is not in any shape to distribute, or even show anybody.
> But it works, and it's pretty speedy. That's enough to encourage me  
> to polish it off.

Sounds like great progress! The TCL sounds interesting -- where did  
you get it? 

> [If you wan't my stuff, you'll have to be C++ capable. I can't
> think in C any more. :-]

Don't worry - we can handle C++, although for the line mode browser  
we wanted portability into places where C++ could not reach. That's  
why the common code (in WWW/Implementation) is all in C. Believe me,  
after writing the NeXT browser in Objective-C it was a wrench to  
conclude that it would have to be deobjectified.

> If you could round up some info on exactly what I can expect to see  
> in an HTML file, and some idea of how you want it formatted [I have  
> the HTML doc and the LineMode browser, but if you've got time to
> give me a little more info...] I'll be ready to tackle that pretty  
> soon.

You ask for info on exactly what you can expect to find in an HTML  
file, but you've read the two HTML files about HTML.  What is missing  
from there?

Here is some discussion about the tags -- where it's not in  
http://info.cern.ch/hypertext/WWW/MarkUp/Tags.html I have updated  
that document now.

Most of the tags are just style tags: this goes for the headings H1  
to H6, the lists UL and OL with list elements LI, the glossary DL  
with elements DT and DD.

<TITLE> ..<TITLE> is designed to be used for putting in the top  
banner of a window, or using as the window  name. It also is what you  
would use in a history list. It shouldn't be displayed in the text  
itself, as usually there is a <H1> heading atteh top of the text  
anyway. A difference is that thet title is designed to make sense out  
of context, whereas the heading is within context. For example,
a title might be "Formatting Characters for Printf -- C reference  
manual" whereas the heading may just be "Formatting characters".

The base address tag is not used, nor is highlighting HP1 etc.

Anchors are used!  The REL attribute is NOT used.

<ISINDEX> is sent by servers to indicate that they will accept a  
search given this document name plus keywords. It turns on a search  
panel when the document is the main window.  An even better  
implementation would have a keyword field at the bottom of the text  
window if the document is a searchable index.  That would make the  
document more self-contained as an item in the user's eyes, and  
reduce screen clutter.

<NEXTID> can be ignored by browsers, only needed for editors.

<XMP> and <LISTING> are used to indicate inserted literal text.
To make life easier for those writing documents (and because we don't  
have entities in the code yet) they are special in that EVERYTHING is  
litteral text until the closing tag - so one can use XMP for giving
examples of HTML for example.  (We really need an escaping method -  
the next parser will have simpl entities like "&lt." for "<".)
Within XMP or LISTING, newlines are significant (and mean "new  
line"!)

<PLAINTEXT> is used to indicate that the rest of the file is in fact
just ASCII. It turns off SGML parsing completely. It's a fudge for
the moment, until we have the document format negociation.
______________________________________

	Structure of documents:

In writing a new generic parser, I wondered whether your text object  
will store the nested structure of a document. At the moment, the  
document is a linear sequence of styles: you can't have lists within  
lists, etc. Ideally, it would be able to handle this - although its  
more difficult for a human writer to handle when formatting the  
document. I would in fact prefer, instead of <H1>, <H2> etc for  
headings [those come from the AAP DTD] to have a nestable  
<SECTION>..</SECTION> element, and a generic <H>..</H> which at any  
level within the sections would produce the required level of  
heading.

For a browser, it is quite satisfactory to flatten the structure back  
into a sequence of styles, but for an editor it isn't. Are you going  
to go for editing capability?

Tim

PS: Shall I put you on the www-talk list?