Comments within style= attributes - safe? - html

I am working on a CMS that generates CSS "style='xyz'" statements from user input.
The user input will be validated but as an additional safeguard, I want to check the validity of the values on generation of the CSS code.
If an invalid value is encountered - e.g. a relative width ("50%") where only absolute values are allowed due to layout restrictions - I would like to return a comment INSIDE the style attribute to help debugging:
<div class="content" style="background-color: lightblue; /* WIDTH was invalid: Only absolute values allowed here */; border: 1px orange dotted;">
Is this "safe", i.e. will all major browsers still parse the settings before and after the comment properly? It is difficult to Google information about this.

It is probably safe but I wouldn't put the wrong values commented into the markup.
Let the user know they did something wrong in the very beginning before you generate markup.
A good idea would be to create such a test case and feed it to the W3C validator to see what it would say says about it.
http://validator.w3.org/

From the top of my head, IE supports it, Fx doesn't.

Related

Can I add the pattern attribute to textarea?

I know that the textarea doesn't support the functionality of pattern, however if I set the pattern variable in html, its still present in the browser.
So I have to execute the pattern verification in js anyways, but is it OK for me to store the pattern in the pattern attribute? As opposed to data-pattern or something, for consistency with the input elements?
You should use data-* attributes for extra attributes and since textarea tag does not support the pattern attribute then adding it like adding value to div.
Hope this helps.
Custom attribute is suppose to have the data- prefix, so I recommend to use that or you could ran into issues when validating your code.
And what happens if such an attribute suddenly become a standard attribute?
More to read:
https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes
https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes#data-*
https://www.w3.org/TR/2011/WD-html5-20110525/elements.html#embedding-custom-non-visible-data-with-the-data-attributes

Cant see my form button or footer on page

I've build a page with a form and for some reason my button for the form and my footer element is not showing up on the page.
I have added a link so you can check out my code. And I know its a HOT MESS! so if you can give me any tips on the css and html please feel free to let me know.
http://jsfiddle.net/jeramiewinchell/j6n0w1tj/
enter code here
Fair point in the edit. I said it was a mess without giving anything positive.
Here are some tips that could improve the HTML (with links for reference):
You should specify a doctype (e.g.: <!doctype html>) instead of having an empty <!DOCTYPE> tag.
http://www.w3.org/TR/html-markup/syntax.html#doctype-syntax
It would be nice to have a <html> wrapping everything, and a <head> wrapping the title and links. I'm not clear if it's technically valid not to have them (the W3C HTML validator will not validate a page without a <head> although it will validate without the <html>), but it's nice and it will help keep things organized.
The links should have a type indicating the mime type (in this case type="text/css").
http://www.w3schools.com/tags/tag_link.asp
Closing empty elements (e.g.: img, link, input) is not mandatory in HTML5, but it is in XHTML. Depending on the doctype that you choose, you should close them accordingly. Using /> at the end is valid for both HTML5 and XHTML, so you may want to consider it.
http://www.456bereastreet.com/archive/201005/void_empty_elements_and_self-closing_start_tags_in_html/
Don't nest <p> tags. Paragraphs are block elements that should contain only phrasing content (= not block/paragraph elements). How to fix it: replace <p class="site_section1"> with a <div class="site_section1">.
http://www.w3.org/TR/html5/grouping-content.html#the-p-element
Always close the block tags that you open. For example, you never close the <p class="site_section1"> (altough as I said in the previous point, you should making it a <div>... and then close it). The result in the browser may be unpredictable.
I mentioned in my comment above (sorry, I don't know the name in English), you should avoid crossed tags/nesting of tags. This is incorrect: <label>...<select></label>...</select>, it should be <label>...</label><select>...</select>.
Again, not mandatory but it could be nice to set a value attribute in the <option> tags. If you don't specify a value, the value sent will be the content inside between the <option> tags (that may be what you want in this case).
Don't forget all the code and to close the tags correctly! Things like this: <button type="submit">Save</buttons </div> can have disastrous results (although it looks more of a typo to me).
Don't close tags twice (e.g.: you have </body> twice)
And for the CSS (also with some links for reference):
Avoid unnecessary styling. E.g.: border-radius:0px is unnecessary because 0 is the default value for border-radius (unless you have defined some previous style and you want to overwrite it).
http://www.w3schools.com/cssref/css3_pr_border-radius.asp
Specifying units is required for values different than 0. E.g.: margin-left:15 is that 15 in px or em?
http://www.w3.org/TR/CSS21/syndata.html#length-units
The units are optional when the value is 0. Some people find it more readable and better because it is shorter; I personally like them. Your call, but always:
Be consistent: if you omit the units for a zero value, do it in all your definitions. It looks awkward to me to see a padding:0 (without units) next to a margin:0px. It will help you read and maintain the code later.
You could merge many styles together. For example: .zonelist23, .zonelist24, and .zonelist25 are the same, you could define one style only (e.g.: .zonelist_bml30) or set all of them together: .zonelist23, .zonelist24, .zonelist25 { ... }
Not mandatory, but nice: The font-family tag should have several names as a "fallback" system. That way, if the browser does not support the first font, it will go to the next and so on.
http://www.w3schools.com/css/css_font.asp
Just out of curiosity: did you meant to put in the stylesheet .header or is it header? I personally try to avoid classes/ids with the same name as a tag to keep the code easier to understand, but that's a personal choice. As far as I know there's nothing against naming a class like a tag.
One way of having fun and learning (you may now think that I have a strange way of having fun and learning):
Go to the W3C HTML Validator.
Click on the the "validate by direct input" tab.
Copy your code in the box.
Click on the "Validate" button.
View the first error, and read the comments (visit the links for reference).
Fix the code according to what you've read.
Click on the "Revalidate" button.
Repeat steps 5-7 until no errors are found.
(You can do the same with the CSS in the W3C CSS Validator)
Please see this fiddle : http://jsfiddle.net/j6n0w1tj/1/
I have corrected your code.
Kindly follow the steps mentioned by #monty82, who has given an excellent explanation on how to proceed with your code.
Wrong html:
<label>..<select></Label><option></option></select>
Correct html
<label>..</label><select><option></option></select>
Tags like <input>,<br> are self closing tags,close it like <input
type="radio"/> and <br/> not as </br>.
Please make sure whether your opening and closing tags match

addthis & google analytics did not pass HTML validation

These are the errors and warnings I got:
Line 135, Column 134: & did not start a character reference. (&
probably should have been escaped as &.)Rk44QGJO&hl=he"></script><noscript><iframe src="…
Line 135, Column 309: The frameborder attribute on the iframe element is obsolete. Use CSS instead.
…ight="300" width="500" frameborder="0"><textarea name="recaptch…
Line 161, Column 116: Attribute addthis:url is not serializable as XML 1.0.
Attribute addthis:title is not serializable as XML 1.0.
Attribute addthis:description is not serializable as XML 1.0.
Attribute addthis:url not allowed on element div at this point.
Attribute addthis:title not allowed on element div at this point.
Attribute fb:like:layout is not serializable as XML 1.0.
Attribute fb:like:layout not allowed on element a at this point.
and this is the addthis code:
<div class="addthis_toolbox addthis_default_style"
addthis:url="http://www.example.com"
addthis:title="title"
addthis:description="description">
<a class="addthis_button_facebook_like" fb:like:layout="button_count"></a>
<a class="addthis_button_tweet" lang="en"></a>
<a class="addthis_button_linkedin_counter"></a>
</div>
Does anyone know how to fix these errors?
To fix attribute fb:like:layout, you can actually remove the following: fb:like:layout="button_count"
since the button count is the default layout.
A bit late to the party, but maybe it helps someone else? I haven't actually tried this implementation myself, but reviewing the code it looks like a good "hack" fix to your problem - providing that you're already using jQuery on your site.
I know people will say "don't worry about it, it's not breaking anything", but when you religiously validate your code (which I believe you should, to find missing closing tags that you've forgotten, etc), these kinds of pesky errors just get in the way of validating your code in the quickest possible way.
Anyway, here is the link: http://www.teslina.com/1879/allgemein/addthis-html5-workaround-js-hack/#sthash.4dHK9Zwl.mkBH3Z0g.dpbs

where can I use "name" attribute (in html)?

I did some code with jquery that take the name attribute !!! OF A DIV !!! and use it in some way.
if in one hand i tryed this code in every browser i have (firefox, chrome, ie 9/8/7, safari, opera, android... all with last update) and it work perfectly, in the other hand i see that - searching with google - "name" is considered only into form, input, textarea, a and other similar.
can i really use it in the way i did? in every html tag I want? or I'll burn forever in the hell?
thank you in advance
seen your answers, I decided to store datas in other way (like adding class and retrieve their name even with jquery).
You can use whatever attribute name you want - but 'name' isn't a valid attribute on the div tag according to the specification, so your markup would technically be invalid.
If as an example, you take this html:
<!DOCTYPE html>
<head>
<title>test</title>
</head>
<body>
<div name="mydiv" class="myclass"></div>
</body>
And validate it here, you'll see that you get this error:
Line 6, Column 41: Attribute name not allowed on element div at this point.
<div name="mydiv" class="myclass"></div>
<a>, <applet>, <button>, <form>, <frame>, <iframe>, <img>, <input>, <map>, <meta>, <object>, <param>, <select>, and <textarea>
https://developer.mozilla.org/en-US/docs/DOM/element.name
To the best of my knowledge, name is mostly used for pairing elements with labels (and in that vein, grouping radio buttons).
EDIT: Mentioning Mike's comment. Name is also used for form submission with GET and POST in a key/value pair sort of way.
Update: It may be worth looking at this post.
OMG Ponies has some good info on the topic:
My understanding is that when Netscape created Javascript, it used the
name attribute. The HTML spec however decided to go with id, but kept
name for backwards compatibility. IME, using the name attribute was
required for Internet Explorer 6 support because the javascript engine
in IE wouldn't read the id attribute - only the name though both were
defined.

Is there a way to create your own html tag in HTML5?

I want to create something like
<menu>
<lunch>
<dish>aaa</dish>
<dish>bbb</dish>
</lunch>
<dinner>
<dish>ccc</dish>
</dinner>
</menu>
Can it be done in HTML5?
I know I can do it with
<ul id="menu">
<li>
<ul id="lunch">
<li class="dish">aaa</li>
<li class="dish">bbb</li>
</ul>
</li>
<li>
<ul id="dinner">
<li class="dish">ccc</li>
</ul>
</li>
</ul>
but it is so much less readable :(
You can use custom tags in browsers, although they won’t be HTML5 (see Are custom elements valid HTML5? and the HTML5 spec).
Let's assume you want to use a custom tag element called <stack>. Here's what you should do...
STEP 1
Normalize its attributes in your CSS Stylesheet (think css reset) -
Example:
stack{display:block;margin:0;padding:0;border:0; ... }
STEP 2
To get it to work in old versions of Internet Explorer, you need to append this script to the head (Important if you need it to work in older versions of IE!):
<!--[if lt IE 9]>
<script> document.createElement("stack"); </script>
<![endif]-->
Then you can use your custom tag freely.
<stack>Overflow</stack>
Feel free to set attributes as well...
<stack id="st2" class="nice"> hello </stack>
I'm not so sure about these answers. As I've just read:
"CUSTOM TAGS HAVE ALWAYS BEEN ALLOWED IN HTML."
http://www.crockford.com/html/
The point here being, that HTML was based on SGML. Unlike XML with its doctypes and schemas, HTML does not become invalid if a browser doesn't know a tag or two. Think of <marquee>. This has not been in the official standard. So while using it made your HTML page "officially unapproved", it didn't break the page either.
Then there is <keygen>, which was Netscape-specific, forgotten in HTML4 and rediscovered and now specified in HTML5.
And also we have custom tag attributes now, like data-XyZzz="..." allowed on all HTML5 tags.
So, while you shouldn't invent a whole custom unspecified markup salad of your own, it's not exactly forbidden to have custom tags in HTML. That is however, unless you want to send it with an +xml Content-Type or embed other XML namespaces, like SVG or MathML. This applies only to SGML-confined HTML.
I just want to add to the previous answers that there is a meaning to use only two-words tags for custom elements.
They should never be standardised.
For example, you want to use the tag <icon>, because you don't like <img>, and you don't like <i> neither...
Well, keep in mind that you're not the only one. Maybe in the future, w3c and/or browsers will specify/implement this tag.
At this time, browsers will probably implements native style for this tag and your website's design may break.
So I'm suggesting to use (according to this example) <img-icon>.
As a matter of fact, the tag <menu> is well defined ie not so used, but defined. It should contain <menuitem> which behave like <li>.
As Michael suggested in the comments, what you want to do is quite possible, but your nomenclature is wrong. You aren't "adding tags to HTML 5," you are creating a new XML document type with your own tags.
I did this for some projects at my last job. Some practical advice:
When you say you want to "add these to HTML 5," I assume what you really mean is that you want the pages to display correctly in a modern browser, without having to do a lot of work on the server side. This can be accomplished by inserting a "stylesheet processing instruction" at the top of the xml file, like <?xml-stylesheet type="text/xsl" href="menu.xsl"?>. Replace "menu.xsl" with the path to the XSL stylesheet that you create to convert your custom tags into HTML.
Caveats: Your file must be a well-formed XML document, complete with XML header <xml version="1.0">. XML is pickier than HTML about things like mismatched tags. Also, unlike HTML, tags are case-sensitive. You must also make sure that the web server is sending the files with the appropriate mime type "application/xml". Often the web server will be configured to do this automatically if the file extension is ".xml", but check.
Big Caveat: Finally, using the browsers' automatic XSL transformation, as I've described, is really best only for debugging and for limited applications where you have a lot of control. I used it successfully in setting up a simple intranet at my last employer, that was accessed only by a few dozen people at most. Not all browsers support XSL, and those that do don't have completely compatible implementations. So if your pages are to be released into the "wild," it's best to transform them all into HTML on the server side, which can be done with a command line tool, or with a button in many XML editors.
Creating your own tag names in HTML is not possible / not valid. That's what XML, SGML and other general markup languages are for.
What you probably want is
<div id="menu">
<div id="lunch">
<span class="dish">aaa</span>
<span class="dish">bbb</span>
</div>
<div id="dinner">
<span class="dish">ccc</span>
</div>
</div>
Or instead of <div/> and <span/> something like <ul/> and <li/>.
In order to make it look and function right, just hook up some CSS and Javascript.
Custom tags can be used in Safari, Chrome, Opera, and Firefox, at least as far as using them in place of "class=..." goes.
green {color: green} in css works for
<green>This is some text.</green>
<head>
<lunch>
<style type="text/css">
lunch{
color:blue;
font-size:32px;
}
</style>
</lunch>
</head>
<body>
<lunch>
This is how you create custom tags like what he is asking for its very simple just do what i wrote it works yeah no js or convoluted work arounds needed this lets you do exactly what he wrote.
</lunch>
</body>
For embedding metadata, you could try using HTML microdata, but it's even more verbose than using class names.
<div itemscope>
<p>My name is <span itemprop="name">Elizabeth</span>.</p>
</div>
<div itemscope>
<p>My name is <span itemprop="name">Daniel</span>.</p>
</div>
Besides writing an XSL stylesheet, as I described earlier, there is another approach, at least if you are certain that Firefox or another full-fledged XML browser will be used (i.e., NOT Internet Explorer). Skip the XSL transform, and write a complete CSS stylesheet that tells the browser how to format the XML directly. The upside here is that you wouldn't have to learn XSL, which many people find to be a difficult and counterintuitive language. The downside is that your CSS will have to specify the styling very completely, including what are block nodes, what are inlines, etc. Usually, when writing CSS, you can assume that the browser "knows" that <em>, for instance, is an inline node, but it won't have any idea what to do with <dish>.
Finally, its been a few years since I tried this, but my recollection is that IE (at least a few versions back) refused to apply CSS stylesheets directly to XML documents.
The point of HTML is that the tags included in the language have an agreed meaning, that everyone in the world can use and base decisions on - like default styling, or making links clickable, or submitting a form when you click on an <input type="submit">.
Made-up tags like yours are great for humans (because we can learn English and thus know, or at least guess, what your tags mean), but not so good for machines.
Polymer or X-tags allow you to build your own html tags. It is based on native browser's "shadow DOM".
In some circumstances, it may look like creating your own tag names just works fine.
However, this is just your browser's error handling routines at work. And the problem is, different browsers have different error handling routines!
See this example.
The first line contains two made-up elements, what and ever, and they get treated differently by different browsers. The text comes out red in IE11 and Edge, but black in other browsers.
For comparison, the second line is similar, except it contains only valid HTML elements, and it will therefore look the same in all browsers.
body {color:black; background:white;} /* reset */
what, ever:nth-of-type(2) {color:red}
code, span:nth-of-type(2) {color:red}
<p><what></what> <ever>test</ever></p>
<p><code></code> <span>test</span></p>
Another problem with made-up elements is that you won't know what the future holds. If you created a website a couple of years ago with tag names like picture, dialog, details, slot, template etc, expecting them to behave like spans, are you in trouble now!
This is not an option in any HTML specification :)
You can probably do what you want with <div> elements and classes, from the question I'm not sure exactly what you're after, but no, creating your own tags is not an option.
As Nick said, custom tags are not supported by any version of HTML.
But, it won't give any error if you use such markup in your HTML.
It seems like you want to create a list. You can use unordered list <ul> to create the rool elements, and use the <li> tag for the items underneath.
If that's not what you want to achieve, please specify exactly what you want. We can come up with an answer then.
You can add custom attribute through HTML 5 data- Attributes.
For example: Message
That is valid for HTML 5. See http://ejohn.org/blog/html-5-data-attributes/ to get details.
You can just do some custom css styling, this will create a tag that will make the background color red:
redback {background-color:red;}
<redback>This is red</redback>
you can use this:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>MyExample</title>
<style>
bloodred {color: red;}
</style>
</head>
<body>
<bloodred>
this is BLOODRED (not to scare you)
</bloodred>
</body>
<script>
var btn = document.createElement("BLOODRED")
</script>
</html>
I found this article on creating custom HTML tags and instantiating them. It simplifies the process and breaks it down into terms anyone can understand and utilize immediately -- but I'm not entirely sure the code samples it contains are valid in all browsers, so caveat emptor and test thoroughly. Nevertheless, it's a great introduction to the subject to get started.
Custom Elements : Defining new elements in HTML