At the top of this README.md (raw code at the top of this page), I am trying to float an image next to a Markdown table. My efforts with the float style property and align attribute in img have been unsuccessful.
As long as your document is hosted on GitHub you can't.
As documented in GitHub's Markup library, after the Markdown is converted to HTML, the...
HTML is sanitized, aggressively removing things that could harm you and your kin—such as script tags, inline-styles, and class or id attributes. See the sanitization filter for the full whitelist.
In other words, anything you include in the Markdown to "style" your document (style tags, inline-styles, etc.) will be stripped out by the sanitizer. If you want control over the look and styling of your documents, then you need to host them somewhere where you have complete control. GitHub is not that place.
your table has width:100% and won't let any elements besides. try changing its width to width :auto and display from block to display:inline-block. also, change the image container to display:inline-block
Related
I know it's wrong to put a block element inside an inline element, but what about the following?
Imagine this valid markup:
<div><p>This is a paragraph</p></div>
Now add this CSS:
div {
display:inline;
}
This creates a situation where an inline element contains a block element (The div becomes inline and the p is block by default)
Are the page elements still valid?
How and when do we judge if the HTML is valid - before or after the CSS rules are applied?
UPDATE: I've since learned that in HTML5 it is perfectly valid to put block level elements inside link tags eg:
<a href="#">
<h1>Heading</h1>
<p>Paragraph.</p>
</a>
This is actually really useful if you want a large block of HTML to be a link.
From the CSS 2.1 Spec:
When an inline box contains an in-flow block-level box, the inline box (and its inline ancestors within the same line box) are broken around the block-level box (and any block-level siblings that are consecutive or separated only by collapsible whitespace and/or out-of-flow elements), splitting the inline box into two boxes (even if either side is empty), one on each side of the block-level box(es). The line boxes before the break and after the break are enclosed in anonymous block boxes, and the block-level box becomes a sibling of those anonymous boxes. When such an inline box is affected by relative positioning, any resulting translation also affects the block-level box contained in the inline box.
This model would apply in the following example if the following rules:
p { display: inline }
span { display: block }
were used with this HTML document:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HEAD>
<TITLE>Anonymous text interrupted by a block</TITLE>
</HEAD>
<BODY>
<P>
This is anonymous text before the SPAN.
<SPAN>This is the content of SPAN.</SPAN>
This is anonymous text after the SPAN.
</P>
</BODY>
The P element contains a chunk (C1) of anonymous text followed by a block-level element followed by another chunk (C2) of anonymous text. The resulting boxes would be a block box representing the BODY, containing an anonymous block box around C1, the SPAN block box, and another anonymous block box around C2.
The properties of anonymous boxes are inherited from the enclosing non-anonymous box (e.g., in the example just below the subsection heading "Anonymous block boxes", the one for DIV). Non-inherited properties have their initial value. For example, the font of the anonymous box is inherited from the DIV, but the margins will be 0.
Properties set on elements that cause anonymous block boxes to be generated still apply to the boxes and content of that element. For example, if a border had been set on the P element in the above example, the border would be drawn around C1 (open at the end of the line) and C2 (open at the start of the line).
Some user agents have implemented borders on inlines containing blocks in other ways, e.g., by wrapping such nested blocks inside "anonymous line boxes" and thus drawing inline borders around such boxes. As CSS1 and CSS2 did not define this behavior, CSS1-only and CSS2-only user agents may implement this alternative model and still claim conformance to this part of CSS 2.1. This does not apply to UAs developed after this specification was released.
Make of that what you will. Clearly the behaviour is specified in CSS, although whether it covers all cases, or is implemented consistently across today's browsers is unclear.
Regardless if it's valid or not, the element structure is wrong. The reason that you don't put block elements inside inline elements is so that the browser can render the elements in an easily predictable way.
Even if it doesn't break any rules for either HTML or CSS, still it creates elements that can't be rendered as intended. The browser has to handle the elements just as if the HTML code was invalid.
The HTML and the CSS will both still be valid. Ideally, you wouldn't have to do something like this, but that particular bit of CSS is actually a handy (and syntactically valid but not semantically valid) way for getting Internet Explorer's double margin bug without resorting to conditional stylesheets or hacks that will invalidate your CSS. The (X)HTML has more semantic value than the CSS, so it's less important that the CSS is semantically valid. In my mind, it's acceptable because it solves an annoying browser issue without invalidating your code.
The HTML is validated independently of the CSS, so the page would still be valid. I'm fairly sure that the CSS spec says nothing about it either, but don't quote me on that one. However, I'd be very careful using a technique like this, as while it might render as intended in some browsers, you'd need to test 'em all—I don't see many guarantees being made.
Are the page elements still valid?
“Valid” in an HTML sense, yes; HTML knows nothing about CSS.
The rendering you get in the browser, however, is ‘undefined’ by the CSS specification, so it could look like anything at all. Whilst you could include such a rule in CSS hacks aimed at one particular browser (where you know how that browser renders this case), it shouldn't be served to browsers in general.
I don't know off the top of my head if this validates any rules but I would recommend using the W3C HTML Validator and the W3C CSS Validator to determine that. Hope this is helpful!
If there is a logic you follow and you end up implementing it like this, it's NOT WRONG. Working things are not "wrong" just because they're weird. Yes, it's quite unusual but it HELPS and it's not a mistake. It's intentional. HTML and CSS should serve you, not the other way around so don't ever listen to comments telling you not to do it just because it's ugly.
It's typical to call a solution "invalid" and suggest a long way around the block. Sometimes you can rethink what you did. But there can be many reasons for what you did and they don't consider them.
I do use blocks inside inlines regularly. It's valid and it's working - it's just not necessary in most cases. So what. Remember when XHTML told us to always put quotes around properties (and everyone yelled at you if you didn't!), now HTML5 allows to omit them if there's no space inside. What happened to that last slash after singular tags? "<br />" ? Come on. Standards change. But browsers keep supporting non-standard things as well. CENTER is deprecated; we're in 2013 and it still works. TABLE for vertical centering? Sometimes it's the only way. DIV inside A to make it hover as you planned? Just go ahead.
Focus on important things.
I think, (x)html is valid, css is valid. Is the result valid? Yes, if it is looking in the browser as You want.
No, It is not a wrong choice. We can use as per requirements.
I have a viewer tab which shows a complete HTML document fetched from the server. The application has a css[main.css] which is applied to all the elements on the screen.
If we apply this to the HTML document shown in the viewer then we loose some formatting like the table border disappears. So we do not want the application's main.css
to be applied to the viewer content. We want to show the document as is.
I see CDATA can be used to do this . The content inside the viewer is wrapped under <div class="ap-mainPanel ap-scrollPanel"> so I want to escape all the content inside
the <div class="ap-mainPanel ap-scrollPanel"> from being rendered using main.css
<![CDATA[
<div class="ap-mainPanel ap-scrollPanel">
</div>
]]>
Not sure how do we specify that we want everything inside the <div class="ap-mainPanel ap-scrollPanel"> to be escaped from applying the main.css
You have 3 main options:
show that tab in <iframe> - as it not accepts parent document
styles
re-apply in main.css rules that will clear content's in
.ap-mainPanel, kind of "css reset"
or predefine already defined rules in main.css to not be applied
in your panel (not() pseudo-class)
You cannot exclude CSS from a part of an HTML document. This has been asked several times at SO, unfortunately mostly with wrong answers given.
If you use a style sheet for a page, or set of pages, you need to design it so that it actually does just what you want. This may require considerably more complicated selectors than you are currently using.
Alternatively, you can display the content as a separate document, as embedded into your main document using iframe (or frame or object, but iframe is usually the most handy). A document displayed in an iframe is rendered independently: only its own style sheets affect the rendering, not the “hosting” document (except that the “hosting document” sets the size of the rendering area and its position).
CDATA sections have nothing to do with this. They disable HTML parsing rules, turning markup to plain text. You don’t want that here.
Running the Ubuntu cloud page http://www.ubuntu.com/business/cloud/overview through http://validator.w3.org/ gives several errors, the majority of which are centred around not having <divs> and <h>s etc. within an <a> tag.
The implementation I'm interested in is the four boxes with arrows, which change colour as you hover over them (as they are <a> links). What is the valid method to implement this?
Valid ways to implement this:
separate links inside each block. Put the :hover effect on the parent div, not the link. Downside: more markup
use only inline elements inside a single link, using CSS to change them into display: block elements if necessary. Downside: potentially less semantic
use an HTML5 doctype, as [X]HTML5 allows this construction. Downside: the less easy-to-validate current moving-target nature of HTML5.
Each one of those can be a (with a :hover effect to change the background color/image), and the , which sits inside, just covers the entire div with a height and a width in your CSS.
I'm editing books/articles in HTML. These texts were printed once and I scan them, convert them into an intermediate XML-Format and then I transform them into HTML (by XSLT). Because some of those texts are extinct from the market today and are only available through the major libraries I want to publish them in a way so that people could possibly cite them by referring to the page numbers in the original document. For this purpose my intermediate XML-format has an element that marks a page-break. Right now I'm working on the XML->HTML transformations and I'm wondering myself how to transform these page breaks in HTML. They should not appear in the final HTML by default (so a simple | doesn't fit) but I plan to wrap these documents with some lightweight JavaScript that will show the markers when needed. I thought about <span>s with a | in it that are hidden by default.
Is there a better, possibly 'semantic' way to this problem?
Page breaks are very much a thing of layout, and HTML isn't designed to describe layout, so you aren't going to find anything that is semantic for this within the language.
The best you can hope for is some sort of kludge.
Since a page break can occur in the middle of a paragraph, and <p> elements can contain only inline elements you can eliminate most of the options from the outset.
The two possibilities that suggest themselves to me are <span> and <a>. The former has no semantics, that latter is designed to be linked to (with a name attribute) or from (with an href attribute), and you could consider a page from an original document something that you might wish to link to.
No matter what element you use, I wouldn't include a marker in it and then hide it with CSS. That sort of presentational flag is something I would consider adding via :before in a stylesheet (combined with a descendent selector for a body class that can be toggled with JS since you want the toggle)
Alternatively, if you want to take a (very) broad view of the meaning of "HTML" you could consider the l element (from the defunct XHTML 2 drafts) and markup each line of the original document. Adding a class would indicate where a new page began (and you could use CSS counters and borders to clearly indicate each page and number it should you so wish). Pity the browser vendors refused to get behind a real semantic markup language and favoured HTML 5 instead.
Use a <div class="Page"> for each page, and have a stylesheet containing:
.Page {
page-break-after: always;
}
Maybe you can use an xml tag not parsed/interpreted by html like <pagebreak/>.
In this way viewing the html the tag will be not rendered but using jQuery or any other Javascript library, transform, when asked, these particular tags in standard or whatsoever visual mark.
I think this can be a semantic approach...
I know it's wrong to put a block element inside an inline element, but what about the following?
Imagine this valid markup:
<div><p>This is a paragraph</p></div>
Now add this CSS:
div {
display:inline;
}
This creates a situation where an inline element contains a block element (The div becomes inline and the p is block by default)
Are the page elements still valid?
How and when do we judge if the HTML is valid - before or after the CSS rules are applied?
UPDATE: I've since learned that in HTML5 it is perfectly valid to put block level elements inside link tags eg:
<a href="#">
<h1>Heading</h1>
<p>Paragraph.</p>
</a>
This is actually really useful if you want a large block of HTML to be a link.
From the CSS 2.1 Spec:
When an inline box contains an in-flow block-level box, the inline box (and its inline ancestors within the same line box) are broken around the block-level box (and any block-level siblings that are consecutive or separated only by collapsible whitespace and/or out-of-flow elements), splitting the inline box into two boxes (even if either side is empty), one on each side of the block-level box(es). The line boxes before the break and after the break are enclosed in anonymous block boxes, and the block-level box becomes a sibling of those anonymous boxes. When such an inline box is affected by relative positioning, any resulting translation also affects the block-level box contained in the inline box.
This model would apply in the following example if the following rules:
p { display: inline }
span { display: block }
were used with this HTML document:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HEAD>
<TITLE>Anonymous text interrupted by a block</TITLE>
</HEAD>
<BODY>
<P>
This is anonymous text before the SPAN.
<SPAN>This is the content of SPAN.</SPAN>
This is anonymous text after the SPAN.
</P>
</BODY>
The P element contains a chunk (C1) of anonymous text followed by a block-level element followed by another chunk (C2) of anonymous text. The resulting boxes would be a block box representing the BODY, containing an anonymous block box around C1, the SPAN block box, and another anonymous block box around C2.
The properties of anonymous boxes are inherited from the enclosing non-anonymous box (e.g., in the example just below the subsection heading "Anonymous block boxes", the one for DIV). Non-inherited properties have their initial value. For example, the font of the anonymous box is inherited from the DIV, but the margins will be 0.
Properties set on elements that cause anonymous block boxes to be generated still apply to the boxes and content of that element. For example, if a border had been set on the P element in the above example, the border would be drawn around C1 (open at the end of the line) and C2 (open at the start of the line).
Some user agents have implemented borders on inlines containing blocks in other ways, e.g., by wrapping such nested blocks inside "anonymous line boxes" and thus drawing inline borders around such boxes. As CSS1 and CSS2 did not define this behavior, CSS1-only and CSS2-only user agents may implement this alternative model and still claim conformance to this part of CSS 2.1. This does not apply to UAs developed after this specification was released.
Make of that what you will. Clearly the behaviour is specified in CSS, although whether it covers all cases, or is implemented consistently across today's browsers is unclear.
Regardless if it's valid or not, the element structure is wrong. The reason that you don't put block elements inside inline elements is so that the browser can render the elements in an easily predictable way.
Even if it doesn't break any rules for either HTML or CSS, still it creates elements that can't be rendered as intended. The browser has to handle the elements just as if the HTML code was invalid.
The HTML and the CSS will both still be valid. Ideally, you wouldn't have to do something like this, but that particular bit of CSS is actually a handy (and syntactically valid but not semantically valid) way for getting Internet Explorer's double margin bug without resorting to conditional stylesheets or hacks that will invalidate your CSS. The (X)HTML has more semantic value than the CSS, so it's less important that the CSS is semantically valid. In my mind, it's acceptable because it solves an annoying browser issue without invalidating your code.
The HTML is validated independently of the CSS, so the page would still be valid. I'm fairly sure that the CSS spec says nothing about it either, but don't quote me on that one. However, I'd be very careful using a technique like this, as while it might render as intended in some browsers, you'd need to test 'em all—I don't see many guarantees being made.
Are the page elements still valid?
“Valid” in an HTML sense, yes; HTML knows nothing about CSS.
The rendering you get in the browser, however, is ‘undefined’ by the CSS specification, so it could look like anything at all. Whilst you could include such a rule in CSS hacks aimed at one particular browser (where you know how that browser renders this case), it shouldn't be served to browsers in general.
I don't know off the top of my head if this validates any rules but I would recommend using the W3C HTML Validator and the W3C CSS Validator to determine that. Hope this is helpful!
If there is a logic you follow and you end up implementing it like this, it's NOT WRONG. Working things are not "wrong" just because they're weird. Yes, it's quite unusual but it HELPS and it's not a mistake. It's intentional. HTML and CSS should serve you, not the other way around so don't ever listen to comments telling you not to do it just because it's ugly.
It's typical to call a solution "invalid" and suggest a long way around the block. Sometimes you can rethink what you did. But there can be many reasons for what you did and they don't consider them.
I do use blocks inside inlines regularly. It's valid and it's working - it's just not necessary in most cases. So what. Remember when XHTML told us to always put quotes around properties (and everyone yelled at you if you didn't!), now HTML5 allows to omit them if there's no space inside. What happened to that last slash after singular tags? "<br />" ? Come on. Standards change. But browsers keep supporting non-standard things as well. CENTER is deprecated; we're in 2013 and it still works. TABLE for vertical centering? Sometimes it's the only way. DIV inside A to make it hover as you planned? Just go ahead.
Focus on important things.
I think, (x)html is valid, css is valid. Is the result valid? Yes, if it is looking in the browser as You want.
No, It is not a wrong choice. We can use as per requirements.