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">
Related
I'm new to XHTML and I keep getting this error and can't find the solution anywhere.
Here's the error:
error.png
Here's my code:
<!DOCTYPE html public "-//project//test.xhtml">
<html>
<head>
<title>Tools</title>
<link href="oof.css" rel="stylesheet"type="text/css">
</head>
<body>
<div class="page">
<!DOCTYPE html public "-//project//test.xhtml"> is not an XHTML Doctype.
The specific error you get is because an identifier has to be PUBLIC or SYSTEM and it is case sensitive.
The Doctype needs to reference the DTD you are validating against, not an XHTML document.
Most XHTML documents will use this Doctype:
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
However, there is little point in using XHTML 1.0 in 2018. You would probably be better off using HTML 5 instead.
If you are using the XML serialisation of HTML 5, then you wouldn't use a Doctype at all.
Most people don't get any benefit from using XML though, and would be better off writing HTML instead. That uses the Doctype:
<!DOCTYPE html>
… and then only for historical reasons to trigger Standards mode in browsers.
You have a lot of errors in your syntax.
LINK tag is a self closing tag.
DOCTYPE html public "...." defines some info. Read about it here
Every opening tag has a closing tag
Here's what it should look like
<!DOCTYPE html public "-//project//test.xhtml">
<html>
<head>
<title>Tools</title>
<link href="oof.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div class="page"></div>
</body>
</html>
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 can't believe what is happening in my website. When I add this line:
<html xmlns="http://www.w3.org/1999/xhtml">
<!DOCTYPE html>
<html>
<head>
Everything works fine. And when I don't, CSS "messes" up, everything becomes different and layout becomes "ugly".
How can this line solve all the problems?!
You're mixing up HTML with XHTML.
Usually a <!DOCTYPE> declaration is used to distinguish between versions of HTMLish languages (in this case, HTML or XHTML).
Different markup languages will behave differently. My favorite example is height:100%. Look at the following in a browser:
XHTML
<!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" xml:lang="en" lang="en">
<head>
<style type="text/css">
table { height:100%;background:yellow; }
</style>
</head>
<body>
<table>
<tbody>
<tr><td>How tall is this?</td></tr>
</tbody>
</table>
</body>
</html>
... and compare it to the following: (note the conspicuous lack of a <!DOCTYPE> declaration)
HTML (quirks mode)
<html>
<head>
<style type="text/css">
table { height:100%;background:yellow; }
</style>
</head>
<body>
<table>
<tbody>
<tr><td>How tall is this?</td></tr>
</tbody>
</table>
</body>
</html>
You'll notice that the height of the table is drastically different, and the only difference between the 2 documents is the type of markup!
That's nice... now, what does <html xmlns="http://www.w3.org/1999/xhtml"> do?
That doesn't answer your question though. Technically, the xmlns attribute is used by the root element of an XHTML document: (according to Wikipedia)
The root element of an XHTML document must be html, and must contain an xmlns attribute to associate it with the XHTML namespace.
You see, it's important to understand that XHTML isn't HTML but XML - a very different creature. (ok, a kind of different creature) The xmlns attribute is just one of those things the document needs to be valid XML. Why? Because someone working on the standard said so ;) (you can read more about XML namespaces on Wikipedia but I'm omitting that info 'cause it's not actually relevant to your question!)
But then why is <html xmlns="http://www.w3.org/1999/xhtml"> fixing the CSS?
If structuring your document like so... (as you suggest in your comment)
<html xmlns="http://www.w3.org/1999/xhtml">
<!DOCTYPE html>
<html>
<head>
[...]
... is fixing your document, it leads me to believe that you don't know that much about CSS and HTML (no offense!) and that the truth is that without <html xmlns="http://www.w3.org/1999/xhtml"> it's behaving normally and with <html xmlns="http://www.w3.org/1999/xhtml"> it's not - and you just think it is, because you're used to writing invalid HTML and thus working in quirks mode.
The above example I provided is an example of that same problem; most people think height:100% should result in the height of the <table> being the whole window, and that the DOCTYPE is actually breaking their CSS... but that's not really the case; rather, they just don't understand that they need to add a html, body { height:100%; } CSS rule to achieve their desired effect.
Its an XML namespace. It is required when you use XHTML 1.0 or 1.1 doctypes or application/xhtml+xml mimetypes.
You should be using HTML5 doctype, then you don't need it for text/html. Better start from template like this :
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>domcument title</title>
<link rel="stylesheet" href="/stylesheet.css" type="text/css" />
</head>
<body>
<!-- your html content -->
<script src="/script.js"></script>
</body>
</html>
When you have put your Doctype straight - do and validate you html and your css . That usually will sove you layout issues.
It sounds like your site has CSS or JS that depends on running in quirks mode. Which is why you need garbage above your doctype to render "correctly". I suggest removing said garbage and then fixing your CSS+JS to actually work in standards mode; you'll save yourself a lot of pain in the long run.
The namespace name http://www.w3.org/1999/xhtml
is intended for use in various specifications such as:
Recommendations:
XHTML™ 1.0: The Extensible HyperText Markup Language
XHTML Modularization
XHTML 1.1
XHTML Basic
XHTML Print
XHTML+RDFa
Check here for more detail
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.
is it possible to use DOCTYPE tag in line 2 or 3 or ... and css works good ? (not line 1)
tag :
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Yes. As long as it comes before your <html> tag, you should be fine. This might happen, for instance, if you put an XML declaration above it. The xml declaration, however, must occur at the very beginning of the file.
Example:
<?xml version='1.0' charset='utf-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>This is an example</title>
</head>
<body>
<h1>This is an example</h1>
<p>
You might even put an xml stylesheet declaration up above your
DTD declaration, which would look like this:
<code><?xml-stylesheet type="text/xsl" href="transform.xsl"?></code>
</p>
<p>But you still can't put any HTML above your DOCTYPE. Sorry.</p>
</body>
</html>
Seems like you are very persistent about doing strange things with your doctype. It's best you always use it AND put it on the first line of your document. If you go arround the web you'll find that almost every website has it like that.
Is there a reason why you don't want to do so?
IE6 will fall into quirks mode if you put anything (including an XML declaration) before the Doctype. So - "no".
Most browsers will fall into quirks mode (AFAIK) if any content appears before it. Don't use hosts who prevent you from using valid markup.
by standards, the DOCTYPE should be the first line. why would you not want to put it there anyways?