I am using few facebook social plugins and I am using the meta header. When validating the page, the W3C validator is throwing the error -> "Error: there is no attribute "property".
I am using the XHTML Transitional doctype - <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Pls Suggest if I have to change the doctype to something else.
Facebook's plugins use Open Graph, which is built on RDFa. It's RDFa that adds the property attribute to elements. Without this addition, plain HTML has no such attribute. (If you ask me, it's a strange design to add a new attribute without namespacing it, and to re-use half of a <meta> tag. But no-one did.)
To validate XHTML-with-RDFa, you'll need the DOCTYPE:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
This means you will have to be writing valid XHTML 1.1. More
In order for a document to claim that it is a conforming HTML+RDFa document, it must provide the facilities described as mandatory in this section. The document conformance criteria are listed below, of which only a subset are mandatory:
All document conformance requirements stated as mandatory in the HTML5 specification must be met.
There should be a version attribute on the html element. The value of the version attribute should be HTML+RDFa 1.0 if the document is a non-XML mode document, or XHTML+RDFa 1.0 if the document is a XML mode document.
There may be a link element contained in the head element that contains profile for the the rel attribute and http://www.w3.org/1999/xhtml/vocab for the href attribute.
Example:
<html version="HTML+RDFa 1.1" lang="en">
<head>
<title>Example Document</title>
</head>
<body>
<p>Moved to example.org.</p>
</body>
</html>
As Open Graph suggests, if you're using HTML5, you're better off just using a prefix attribute like this:
<!doctype html>
<html prefix="og: http://ogp.me/ns#">
<head>
<title>HTML5 site</title>
<meta property="og:title" content="The Rock" />
</head>
<body>
</body>
</html>
You can leave the doctype as is and it will validate.
This approach has also been recommended by an Open Graph developer.
Related
I'm wondering if this is a quirk in Dreamweaver:
The first tag in my html5 document is:
<!doctype html>
...and the last tag is:
</html>
When validating the document (W3C) from within Dreamweaver, I get this error:
Tag must be paired, no start tag: [ </html> ]
Could it be that Dreamweaver doesn't recognize the first tag with !doctype?
<!doctype html> is not an opening-tag. It's an SGML doctytpe declaration.
The <html> opening tag goes after it, like so:
<!doctype html>
<html>
<head>
</head>
<body>
</body>
</html>
Backstory: SGML doctype declarations are usually far more complicated, and when HTML was ostensibly an application of SGML (e.g. in HTML4.01) then HTML documents needed full-form SGML DTDs like this:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
...however, ever since HTML5 was declared as "a living standard" without version numbers, and no-longer either SGML nor XML (rip XHTML) there was no need for a HTML5 DTD anymore, but for compatibility purposes the W3C and WHATWG said that <!doctype html> (without the older SGML PUBLIC/SYSTEM parts, and without a URI to the actual DTD) should be used.
See here for details: Where is the HTML5 Document Type Definition?
So, I wanted to be strict on me and took one of HTML5 pages and validated it as XHTML Strict -- all the way.
Fixed every error reading the very helpful error messages. Now the entire page is fully XHTML compliant. But the page shows only the DIVS containing the ads. The main DIV containing the page matter is gone, haha!
Here's the page for your enjoyment:
http://mypollingcenter.com/charts1.htm
Well, I apologize. The problem was that in my over-zealousness, I changed
this line:
<script src="../avazyabadu/kramaanukrama.js" type="text/javascript"></script>
to this:
<script src="../avazyabadu/kramaanukrama.js" type="text/javascript"/>
Empty tag/element rule, you know.
So, the validator took the whole thing as JavaScript, maybe?
Lessons I learned:
That JavaScript external file reference is an exception to the XHTML/XML rule. Keep the closing tag.
The “space before slash” rule is no more with XHTML.
Mark up fully compliant with strict XHTML validate as HTML5, provided you switch headings as below.
XHTML does not need character set declaration if your page is in UTF-8
Use this Validator (Not this one)
XHTML top lines:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
HTML top lines:
<!DOCTYPE html>
<html lang="en-US">
<head>
<meta charset="utf-8">
What is the correct way to use start tag when creating with HTML5
IE: HTML 4 Strict is like this
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
The standard has been simplified because the previous doctypes were too cryptic. The new doctype is simply <!DOCTYPE html> . You may wonder why it is not <!DOCTYPE html5> but it is simply because it is just an update to the standard of HTML and not a new version of anything. As you can see below, all elements can now have a language attribute.
The <html> element is the root element of a document. Every document
must begin with this element, and it must contain both the <head> and
<body> elements.
It is considered good practice to specify the primary language of the
document on this element using the lang attribute.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello World</title>
</head>
<body>
<h1>Hello World</h1>
<p>
Jamie was here.
</p>
</body>
</html>
More info: https://dev.w3.org/html5/html-author/#doctype-declaration
you just use
<!DOCTYPE html>
<html>
</html>
First of all, html5 doctype is not case sensitive.
Either one of these three will work:
1) <!DOCTYPE html>
2) <!DOCTYPE HTML>
3) <!doctype html>
You can check the validity here.
It's as simple as
<!DOCTYPE html>
According to the WWW Consortium, the organization responsible setting current web standards, no one has answered this correctly.
The current standard for language declaration is
Always use a language attribute on the html tag to declare the default
language of the text in the page. When the page contains content in another
language, add a language attribute to an element surrounding that content.
Use the lang attribute for pages served as HTML, and the xml:lang attribute
for pages served as XML. For XHTML 1.x and HTML5 polyglot documents, use both
together.
W3C HTML Language Tag Page
Here is the answer regarding DOCTYPE declaration
Use the following markup as a template to create a new HTML document using a
proper Doctype declaration. See the list below if you wish to use another DTD.
W3C DOCTYPE Standards
<!DOCTYPE html>
<html>
<head>
<title>An HTML standard template</title>
<meta charset="utf-8" />
</head>
<body>
<p>… Your HTML content here …</p>
</body>
</html>
Hope this helps.
You use...
<!DOCTYPE html>
followed by your HTML tag etc..
You only need this:
<!DOCTYPE html>
<html>
...
There are several points here. This is supported by all browsers, even old ones like IE6/IE7. All browsers actually nee "html" part from doctype declaration to jump into standards mode.
<!-- simplified doctype works for all previous versions of HTML as well -->
<!doctype html>
Learning Resource:
http://diveintohtml5.info/
http://www.html5doctor.com
The start tag <html> is optional in HTML5, as in HTML 4.01. If used, it must be the first tag. It has different optional attributes: the global attributes of HTML5, and the special manifest attribute. The most common useful attribute in the <html> tag is the lang attribute.
(The doctype declaration is something quite different, and not a tag at all.)
The clearest most definitive answer of what the standard says seems to be for HTML 5.3 at:
http://w3c.github.io/html/syntax.html#the-doctype
Note especially the list-items 1 and 3 which specify that the doctype-statement is case-insensitive. Also note the number of spaces inside the statement can vary.
And note the clause "A DOCTYPE is a required preamble."
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Are self-closing tags valid in HTML5?
For example:
<div id="myDiv" />
Something would then be done to populate this div using Javascript.
Is this valid HTML?
No. HTML 4.x doesn't have any concept of self closing tags.
It is valid in XHTML.
Div's are not valid self closing tags. To have an empty div it would be better to do this:
<div id="myDiv"></div>
According to the XML declaration and the XHTML 1.0 and 1.1 document definitions, this is fine: the null-end tag (>) may be used when immediately following the null-end start tag closer (/), and your code is equivalent to <div id="myDiv"></div>.
It's a different matter entirely whether any particular consumer will be able to process this correctly.
The SGML declaration used by HTML 4.01 allows tag shortening, but it has a different syntax for the null-end tags; there you can write <div id="abc"/this is a non-empty div/. Again, mileage may vary as for browser support. (My money is on "none".)
Future versions of HTML (HTML5? if that name is still alive) are no longer implemented as SGML languages, and therefore they simply allow what they say they do, without recourse to a formal grammar.
I ran these two blocks of code through the W3C validator. Copy and paste the code into the input under the Validate by Direct Input tab to see the results for yourself.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>title</title>
<meta http-equiv="content-type" content="text/html;charset=UTF-8" >
</head>
<body><div id="Mydiv" /></body>
</html>
The code block with Doctype of transitional HTML 4.01 failed the validation process.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<title>Test</title>
<meta http-equiv="content-type" content="text/html;charset=UTF-8" />
</head>
<body><div id="Mydiv" /></body>
</html>
When I added the XHTML 1.0 transitional doctype, changed the meta tag to a self closing tag, and added in the html xmlns line, the validation passed.
So to answer the first half of your question, it is valid HTML under the XHTML 1.0 Transitional doctype. Whether or not you can use javascript to properly populate it, I am not sure.
Self Closing Tags in XHTML as implemented by browsers:
What are all the valid self-closing elements in XHTML (as implemented by the major browsers)?
Self Closing tags in html5:
Are (non-void) self-closing tags valid in HTML5?
No, it's valid XML (not HTML), and as far as I know, will only be accepted if the document is send with an application/xml mimetype.
However, it may work with XHTML, and the XHTML Doctype declaration.
I have a warning on the line including the javascript file.
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<title></title>
<script type="text/javascript" src="scripts/jquery.js"></script>
</head>
<body>
The warning is "Multiple annotations found at this
line:
- Undefined attribute name (src).
- Undefined attribute name
(type)."
I can't see where the problem is!
It's the doc type. Eclipse is going to validate the DOM against the DTD. If unknown entities are not clearly defined in the DTD, then Eclipse will raise warnings.
In the absence of an explicit doctype, you should check if the Property dialog for the file has a page for deciding what doctype to use as a default. HTML5 was only very recently added: http://dev.eclipse.org/mhonarc/lists/wtp-dev/msg07790.html .
Instead of <!DOCTYPE html>, using this
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">