Is it ok not to include such lines in a HTML file? Removing these lines makes the code look more clean.
<!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">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
When I use dreamweaver to create a HTML file, these lines are automatically included.
No, you should NOT remove those lines.
You can, however, switch the <!doctype>-declaration to the one of HTML5, since that will still trigger standards mode in all current browsers, even though they don't yet implement HTML 5. It looks like the following:
<!DOCTYPE html>
Which is a bit more clean than the ordinary one you use looks like. You can also read a little more about the new doctype-declaration here. You can also learn more about what will change in HTML5 here.
No that is not allowed. It sets the character encoding, i.e. how the browser should read it.
But the new HTML5 elements make the whole thing look easier and cleaner. So:
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
becomes --> <!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
lang="en"
xml:lang="en">
becomes --> <html lang="en">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8">
becomes --> <meta charset="UTF-8">
<link rel="stylesheet" href="style.css" type="text/css">
becomes --> <link rel="stylesheet" href="style.css">
So the whole code in the <head> becomes:
<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8">
<link rel="stylesheet" href="style.css">
No, you shouldn't remove these lines. The first two lines tell the browser what type of document your page is, and helps the browser render it properly.
The third line tells the browser what character set you're using, in this case so that it knows to render non-latin characters properly.
Those declares the DOCTYPE, which shouldn't be forgotten to add.
Why?
Why specify a doctype? Because it
defines which version of (X)HTML your
document is actually using, and this
is a critical piece of information
needed by browsers or other tools
processing the document.
For example, specifying the doctype of
your document allows you to use tools
such as the Markup Validator to check
the syntax of your (X)HTML (and hence
discovers errors that may affect the
way your page is rendered by various
browsers). Such tools won't be able to
work if they do not know what kind of
document you are using.
But the most important thing is that
with most families of browsers, a
doctype declaration will make a lot of
guessing unnecessary, and will thus
trigger a "standard" parsing mode,
where the understanding (and, as a
result, the display) of the document
is not only faster, it is also
consistent and free of any bad
surprise that documents without
doctype will create.
You can remove the DOCTYPE, html tags and meta tags and still have valid HTML, and if you are happy for your page to take browser default styling they can be safely omitted. The content type and charset can be specified by the HTTP headers if you prefer. As others have already pointed out, the DOCTYPE will affect how styling instructions are interpreted, and also how HTML parsers interpret some invalid markup, so you will need to allow for this.
Related
I am still pretty new to HTML and programming in general so this is more of a curiosity question but I am asking as I want to use it the right way.
Whenever I have to initiate an HTML document I start it as below and never observed any issues.
However, when I work in Adobe Dreamweaver and create a new document there it always shows me the below initiation.
Of course I can overwrite this but I would like to know what is the difference and when it would make sense to use any of Adobe's suggested attributes or to add something else to my first four lines.
Can someone help me with this ?
My current initiation:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<!-- ... -->
HTML initiation shown in Dreamweaver:
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- ... -->
Many thanks in advance,
Mike
<!DOCTYPE html>
This is HTML 5. The current standard.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
This is XHTML 1.0 Transitional. A standard from 2000 designed to combine the transition from HTML 3.2 (1997) to HTML 4 (1998) and XML (which never saw wide use, except while pretending to be HTML 4.
can you explain the single attributes that are different to mine and when it would make sense to use any of them ? Esp. regarding
"PUBLIC",
That isn't an attribute. The PUBLIC portion of a Doctype declaration tells the client where it can download the DTD. (As opposed to the SYSTEM portion which gives it an identifier that it can use to look it up from a local catalogue).
Browsers have never cared about DTDs.
"xmlns",
XML Namespace. It lets you distinguish between elements and attributes that have the same name but are from different specifications.
"http-equiv"
"This is equivalent to an HTTP header with this name"
It is largely a joke. Nothing really implements this except for the character encoding portion of the content-type header and HTML 5 gives much nicer syntax for specifying that.
"content".
The value of the above.
Your first declaration is a HTML5 declaration which is the current standard.
The declaration produces by Dreamweaver is a deprecated XHTML 1.0 Transitional declaration (maybe your Dreamweaver is not up-to-date ?).
See here for more information on doctype
I want a strict but fully compatible html5 alternative to:
<!doctype html>
Basically I want to ensure the use of closing tags just to keep everything well readable, consistent and highlighted clearly in editors.
The answer to this question is to HTML 5, as XHTML-1.0-strict is to HTML 4.
Thanks in advance.
There is no doctype for "strict" XHTML5 validation. For XHTML5 the doctype is even optional, as the doctype is only for stopping the browser to switch to quirksmode. There is no such quirksmode for XHTML. It is recommended to use the HTML5 doctype (with capitalised DOCTYPE) if you are planning to use it as a polyglot document. In that case you would use the doctype:
<!DOCTYPE html>
However, if you want to validate as if the document is using XHTML style syntax, you can achieve that using the advanced options of the validator.
Go to http://validator.nu
Switch to "text field" in the select box (or point it to your online document but make sure it is served as XHTML not text/html
If using the text field paste in your document. In my case I used the following:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<meta charset="UTF-8" />
</head>
<body>
<p>test
</body>
</html>
Select XHTML5 + SVG 1.1 + MathML 3.0 from the Preset field. This will pre fill the scheme as http://s.validator.nu/xhtml5.rnc http://s.validator.nu/html5/assertions.sch http://c.validator.nu/all/
Click Validate
Using my document it will warn about the missing close </p>.
Lets say I have the following file in called index in the directory D:\Experimental:
<?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>
<title>Minimal XHTML 1.1 Document</title>
</head>
<body>
<p>This is a minimal XHTML 1.1 document.</p>
</body>
</html>
If I open the link
file:///D:/experimental/index.html
I get to see the html, but it seems that the character encoding defaults to Western (ISO-8859-1), I can see this when I click view -> character encoding in firefox.
I want to display this in UTF-8 because Western (ISO-8859-1) doesn't display some characters correctly. Does anyone know how to fix this?
You should include:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
in your HEAD element.
Edit
I've just tried your example in Firefox on the Mac, and even without the meta tag, it correctly interprets the document as UTF-8. The Standard seems to indicate that it should use the XML processing instruction, but that you should also use the correct HTTP headers. Since you're not sending headers (because you're not using HTTP) you can specify them with the meta tag.
Maybe try adding
<meta http-equiv="content-type" content="text/html;charset=utf-8" />
in <head> section?
When loading files from disk, your browser does not have an HTTP Content-Type header to read the encoding from, so it guesses. To guess the document encoding it uses your operative systems current encoding, the actual bytes that are in the files and information inside the file itself.
As Jonathan wrote, you can add a
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
element that will help the browser using the correct content type. Anyway, note that that element will often be ignored by browsers if your document is sent from a misconfigured HTTP server that explicitly specifies another encoding the Content-Type header.
I am building a webpage, and I found a problem which I cannot solve. If I declare the DOCTYPE, the page breaks completely, and if I don't declare it, the IE version won't work properly (the drop down menus won't drop). But, despite of it's broken, if I declare the DOCTYPE, the dropdown menus work at every explorer, including IE. So I really don't know what to do, any idea? I'm currently declaring the DOCTYPE as: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> but I've tried other options and they don't work neither.
Last time I posted here the free server blocked the page (probably too many users, as I'm the only one getting in currently), but these are 2 examples of the page:
with DOCTYPE: http://newfutureuniversity.org/project/
without DOCTYPE (dropdown menus not working with IE9):
http://newfutureuniversity.org/learn/
Any help would be appreciated. Even if it's just to orientate me about where to start searching, as I could't find anything similar.
Using or not using the doctype for modern web pages is no longer optional and is required. It is the very first thing that goes down on a page and never changes. If you created a page without one to begin with, then your whole page is set in quirks mode. Trying to fix it or change it by adding/removing the doctype is, essentially, changing the rules and the target as you go along.
Trying to use jQuery to fix this now is just sinking you into a deeper hole. Add the doctype, use a modern browser to get everything how you want it (IE is not a modern browser), then work on getting IE to follow along.
The charset you should be using is <meta charset="utf-8">
for HTML5 it is nice and small, you have an XHTML declaration
it can simply be:
<!DOCTYPE html>
for HTML 5
Using XHTML tells the parser to be much more strict in what it accepts. you have no <html> root in your document (HTML5 won't care about this).
content type specification is different in HTML5 as well
instead of <meta http-equiv="content-type" content="text/html; charset=iso-8859-1" /> you can use <meta charset="iso-8859-1" /> if that is your desired character set.
In a search towards minimalistic webcoding practices I saw this on the top of my webpages:
<!doctype html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="nl" xml:lang="nl">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="language" content="nl"/>
A: when should one keep the second line (xmlns) and when can it be removed?
B: my website is multilingual so pages come in variety of languages. I kept the xmlns since I swa you can put in lang= and xml:lang= so thought that might be handy, but I don't use xml I think... just php generated contents etc. UPDATE I just got advise to use <html lang="de"> which will suffice for me. True?
C: when does one need the third line http-equiv? When can it be removed entirely?
D: do browsers recognize/process the fourth line or do they skip it nowadays?
Thanks very much!
If you haven't already, read up on HTML5 here or maybe here, and maybe even here. HTML5 is the latest HTML spec currently under development by the W3C, and is pretty much awesome.
For your questions:
Q1: See this SO question. Basically, you won't need the xmlns or xml:lang attribute.
Q2: Yes, see below.
Q3: You don't need to specify content-type anymore, however you should always specify the encoding (see below). In reality, though, you can use either one, so I would just stick with the short version. See this SO question for more info.
Q4: That's a difficult question to answer because it really depends on the browser / version. However, it's a moot point since the lang attribute should really be moved into the html tag (again, see below).
Below is what I consider the bare minimum a proper web page should include, (sans the comments):
<!DOCTYPE html>
<html lang="en"> <!-- use whatever language code is appropriate here -->
<head>
<meta charset="utf-8"> <!-- utf-8 is universally the best encoding option -->
<title>My Cool Website</title>
</head>
<body>
</body>
</html>