# Introduction
# Introduction
* My name is Sam Ruby
** IBM, Emerging Technology
** Co-chair, W3C HTML WG
** FeedValidator
# Introduction
* My name is Sam Ruby
** IBM, Emerging Technology
** Co-chair, W3C HTML WG
** FeedValidator
** more
# Introduction
# Introduction
# Intertwingly
# Ground Rules
# Ground Rules
* Everything presented here will be online
# Ground Rules
* Everything presented here will be online
* "most important" stuff first
# Ground Rules
* Everything presented here will be online
* "most important" stuff first
* Ask questions!
# Ground Rules
* Everything presented here will be online
* "most important" stuff first
* Ask questions!
* Presentation contains code
# Ground Rules
* Everything presented here will be online
* "most important" stuff first
* Ask questions!
* Presentation contains code
** Don't focus on the details
# Ground Rules
* Everything presented here will be online
* "most important" stuff first
* Ask questions!
* Presentation contains code
** Don't focus on the details
** Focus on social ramifications
# Question
How did you learn HTML?
# Question
How did you learn HTML?
* Reading the spec?
# Question
How did you learn HTML?
* Reading the spec?
* Formal education?
# Question
How did you learn HTML?
* Reading the spec?
* Formal education?
* From a book?
# Question
How did you learn HTML?
* Reading the spec?
* Formal education?
* From a book?
* View Source?
# Question
How did you learn *SVG*?
* Reading the spec?
* Formal education?
* From a book?
* View Source?
# Where's the source?
# Where's the source?
# Most People's Experience
# Most People's Experience
# Scour
# The problem
View-source sounds good... but what is the downside?
# The problem
View-source sounds good... but what is the downside?
!images/red-pill.jpg(Red Pill)!
You have to be willing to seek and see the truth
# Beyond XHTML
# Postel's Law
# Postel's Law
* "Be conservative in what you do;
# Postel's Law
* "Be conservative in what you do;
* be liberal in what you accept from others"
# MIME Type
# MIME Type
* text/html = forgiving
# MIME Type
* text/html = forgiving
* application/xhtml+xml = draconian
# mime type
* text/html = forgiving
* application/xhtml+xml = draconian
p. Choose wisely.
# mime type
* text/html = forgiving
* application/xhtml+xml = draconian
p. choose wisely.
"XHTML" served as text/html is *not* processed as XML.
# mime type
"XHTML" served as text/html is *not* processed as XML.
# mime type
xhtml served as text/html is *not* xhtml
* CSS acts differently
* JavaScript acts differently
* Namespaces don't work
# mime type
"XHTML" served as text/html is *not* processed as XML.
* CSS acts differently
* JavaScript acts differently
* Namespaces don't work
* Parsed differently
# mime type
"XHTML" served as text/html is *not* processed as XML.
* CSS acts differently
* JavaScript acts differently
* Namespaces don't work
* Parsed *subtly* differently
# mime type
"XHTML" served as text/html is *not* processed as XML.
* CSS acts differently
* JavaScript acts differently
* Namespaces don't work
* Parsed *subtly* differently
p. More details.
# XHTML difference: script tags
pre.
# XHTML difference: script tags
pre.
p. Eats the rest of your page in text/html mode.
# XHTML difference: br tags
pre.
# XHTML difference: br tags
pre.
p. *TWO* line breaks
# Coping
# Coping
{{{ Ruby
HTML_VOIDS = %w(area base br col command embed
hr img input keygen link meta param source)
==doc.get_elements('//*[not(* or text())]').each do |e|==
e.text===''== unless HTML_VOIDS.include? e.name
end
}}}
# XHTML difference: pre tag
pre.
line
# XHTML difference: pre tag
pre.
line
HTML: one line
# XHTML difference: pre tag
pre.
line
HTML: one line
XHTML: blank line followed by line
# Tolerance
# Tolerance
* Tolerance of User Mistakes
# Tolerance
* Tolerance of User Mistakes
* Tolerance of Different Values / Perspectives
# Tolerance of User Mistakes
How many anchor tags in the following?
<table>
<tr><td>foo</tr>
<a name='bar'>x
<plaintext>
<a name='baz'>z
# Tolerance of User Mistakes
How many anchor tags in the following?
<table>
<tr><td>foo</tr>
<a name='bar'>x
<plaintext>
<a name='baz'>z
Answer: 1
# Tolerance of User Mistakes
How many anchor tags in the following?
<table>
<tr><td>foo</tr>
<a name='bar'>x <plaintext> *<----------------*
<a name='baz'>z
Answer: 1
p. More details.
# Tolerance of User Mistakes
Where does that one anchor "point"?
<table>
<tr><td>foo</tr>
<a name='bar'>x
<plaintext>
<a name='baz'>z
# Tolerance of User Mistakes
Where does that one anchor "point"?
*<----------------*
<table>
<tr><td>foo</tr>
<a name='bar'>x
<plaintext>
<a name='baz'>z
Answer: *before* the table
# HTML2XML, XML2HTML
# Three ways to embed SVG:
{{{ HTML
<object data="image.svg" height="48" width="48"></object>
<embed src="image.svg" height="48" width="48"></embed>
<img src="image.svg" style="height:48; width:48"/>
}}}
# Three ways to embed SVG:
{{{ HTML
<object data="image.svg" height="48" width="48"></object>
<embed src="image.svg" height="48" width="48"></embed>
<img src="image.svg" style="height:48; width:48"/>
}}}
* Guess which doesn't work in Firefox today?
# Three ways to embed SVG:
{{{ HTML
<object data="image.svg" height="48" width="48"></object>
<embed src="image.svg" height="48" width="48"></embed>
<img src="image.svg" style="height:48; width:48"/>
}}}
* Guess which doesn't work in Firefox today?
* Guess why?
# Inline vs Embed?
# Implications for SVG
Embed
Inline
# Implications for SVG
* SVG integrates better with XHTML
# Implications for SVG
* SVG integrates better with XHTML
** Nobody uses XHTML
# Implications for SVG
* SVG integrates better with XHTML
** *ALMOST* nobody uses XHTML
# Implications for SVG
* SVG integrates better with XHTML
** *ALMOST* nobody uses XHTML
* SVG in HTML the answer?
# Graceful degradation
# Graceful degradation
p. Avoid self-closing syntax.
pre.
# Graceful degradation
p. Avoid self-closing syntax.
pre.
p. Unknown tags may be ignored, but naked text will be displayed.
pre.
# Validation
* SVG is valid in HTML5
# Validation
* SVG is valid in HTML5
* Other namespaces are not
# Validation
* SVG is valid in HTML5
* Other namespaces are not
* All generated SVGs contain foreign namespaces
# Validation
* SVG is valid in HTML5
* Other namespaces are not
* All generated SVGs contain foreign namespaces
** Will tend to discourage use of SVG
# Validation
* SVG is valid in HTML5
* Other namespaces are not
* All generated SVGs contain foreign namespaces
** Will tend to discourage use of SVG
** Will undermine credibility of the validator
# Validation
* SVG is valid in HTML5
* Other namespaces are not *currently* valid
* All generated SVGs contain foreign namespaces
** Will tend to discourage use of SVG
** Will undermine credibility of the validator
# Watch this space
Other namespaces are not *currently* valid
# Watch this space
Other namespaces are not *currently* valid
* Bug 7510
# Watch this space
Other namespaces are not *currently* valid
* Bug 7510
** HTML defines mapping of bytes to DOM
*** element names may contain colons
** SVG defines valid set of elements in the SVG namespace
*** doesn't define any element names with colons
# Watch this space
Other namespaces are not *currently* valid
* Bug 7510
* Microsoft proposal
# Watch this space
Other namespaces are not *currently* valid
* Bug 7510
* Microsoft proposal
** Doesn'tmatch IE behavior
# Validation
# Validation
Conclusions:
* Dangers warned about are real
# Validation
Conclusions:
* Dangers warned about are real
** apply in certain situations
# Validation
Conclusions:
* Dangers warned about are real
** apply *only* in certain situations
** may not apply in the situations that the validator flags
# Validation
Conclusions:
* Dangers warned about are real
** apply *only* in certain situations
** may not apply in the situations that the validator flags
** in many cases, amount to recommendations (e.g. font => style)
# Validation
Conclusions:
* Dangers warned about are real
** apply *only* in certain situations
** may not apply in the situations that the validator flags
** in many cases, amount to recommendations (e.g. font => style)
** omitted end tags are more likely to cause hard to debug problems
# Validation
Conclusions:
* Dangers warned about are real
** apply *only* in certain situations
** may not apply in the situations that the validator flags
** in many cases, amount to recommendations (e.g. font => style)
** omitted end tags are more likely to cause hard to debug problems
*** not flagged though
# My first SVG
# Beyond XHTML
# Beyond XHTML
# Demo
# Demo
# Demo
# Result
# Google Chrome Frame
# Google Chrome Frame vs SVG
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
** Few people do
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
** Few people do
** High percentage of people who do make keynotes though
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
** No animation
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
** No animation
** No Firefox
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
** No animation
** No Firefox
** Don't go there
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
* Does support embed
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
* Does support embed
** links are sandboxed
# Google Chrome Frame vs SVG
* Doesn't support application/xhtml+xml
* Does support <img src="example.svg">
* Does support embed
* Content negotiation could be improved
# Recap
# Recap
* Show *your* source
# Recap
* Show *your* source
* Be tolerant of users
# Recap
* Show *your* source
* Be tolerant of users - they outnumber you!
# Recap
* Show *your* source
* Be tolerant of users - they outnumber you!
* Specs that seem arbitrary generally aren't
# Recap
* Show *your* source
* Be tolerant of users - they outnumber you!
* Specs that seem arbitrary generally aren't
* May need multiple validator profiles
# Questions?
# Questions?