browser detection and redirection

[=?ISO-8859-1?Q?G=E9rard_Talbot?=]

John Dunlop wrote :

Gérard Talbot:


Fine, but...


Well, that's their prerogative, but why would they hold expectations
about how their document will be rendered if they realise that
documents are rendered according to the user-agent?

Let's try an example. If I use <table> and define the data with <tr>,
<td>, <col>, <colgroup>, <caption>, <thead>, <tfoot>, etc., all
according to HTML 4.01 spec, then, as an author, I will expect such to
be rendered as a graphical table within my graphical browsers. The spec
even gives examples (.gif, .png) of how the table could be rendered.
Also, block-level elements usually begin a new line; inline elements do
not usually begin a new line.
"block-level elements are formatted differently than inline elements.
Generally, block-level elements begin on new lines, inline elements do not."
HTML 4.01, Section 7.5.3 Block-level and inline elements
http://www.w3.org/TR/html4/struct/global.html#h-7.5.3

So, in a visual browser, I will have certain expectations.

HTML 4.01, section 11.3 Table formatting by visual user agents
http://www.w3.org/TR/html4/struct/tables.html#h-11.3

Of course, in different media (say, a speech browser), I should have
less expectations or at least, my expectations should be different.

In a text browser, I may expect the table to have no border and no frame
because by default, a table should not have any.

It is impossible,

for example, to know how a document will be rendered by a user-agent on
a platform or medium that is beyond your ken.


See my responses to Ben C.


Imagine a user-agent where (spatial) position makes no sense;

I understand and agree with you that HTML is a language originally
designed to describe the structure of a document and is not a language
designed for layout and formatting (presentation).

imagine a

user-agent where stylesheets are off;

That's a checkpoint in WCAG.

imagine a user-agent that doesn't

support absolute positioning; imagine a user-agent who only reads the
HTML document because all author and user stylesheets have been
removed;

Good browsers have a setting making this possible. It's an UAAG (User
Agent Accessibility Guideline), actually. Firefox and Seamonkey have
View/Style/None.

imagine a user-agent with images off; imagine a user-agent

that doesn't support images.

This is also a checkpoint in WCAG 1.0. Making sure that the webpage is
still usable, navigationable, readable, accessible if images are turn off.

I am sure there are countless scenarios

beyond my imagination.

Yes, this is why good web design should make sure that the webpage looks
reasonable, can function (content accessible, links or navigation
usable, working) when all the formating is removed and when the user
sees/read the document via the browser (user agent) default formating
(browser stylesheet). This is a WCAG 1.0 checkpoint actually.
That's why people should test with Lynx 2.8.6 or text browser.

Gérard

 

[Chaddy2222]

Gérard Talbot:


Fine, but...


Well, that's their prerogative, but why would they hold expectations
about how their document will be rendered if they realise that
documents are rendered according to the user-agent? It is impossible,
for example, to know how a document will be rendered by a user-agent on
a platform or medium that is beyond your ken.

Good point, I am thinking Mobile devices here, they would offten render
things in a different way, just because they just don't have the screen
space of your lap top of desk top PC.

See my responses to Ben C.


Imagine a user-agent where (spatial) position makes no sense; imagine a
user-agent where stylesheets are off; imagine a user-agent that doesn't
support absolute positioning; imagine a user-agent who only reads the
HTML document because all author and user stylesheets have been
removed; imagine a user-agent with images off; imagine a user-agent
that doesn't support images. I am sure there are countless scenarios
beyond my imagination.

Yes, my Screen Reader for one.
Take a look at a demo of Jaws, it users IE6 to render pages, but it
only reads the HTML, I am not sure about the oral propities in CSS
though, although I believe recent versions might though.

Sound advice.

I could not agree more.

Agreed.

Yes, and I wish more web designers would share these views, a lot think
it's a visual medium.