I am trying to do a hover->highlight effect on the cells of the table in this fiddle, so they will appear to look like buttons. I can't use any javascript or CSS, but I can use HTML5. Does anyone know how to do it. I know there is an onmouseover attribute in HTML5, just not much experience yet.
Thanks!
You can't. If you want to change the appearance of a given element based on user's behavior you have to use JavaScript (event based) or the CSS pseudo class :hover.
However, if you can edit the HTML of your content, then you should be able to insert a custom <style> element or add event listeners. Note that the first isn't valid in HTML4*, in HTML5 you can use the scoped attribute to style only a given scope (but I don't think this behavior is implemented in any browser yet).
*This solution should work, even if the resulting code HTML4 isn't valid any more.
Related
Is there any harm if custom tags are used and created based on one's choice?
like the one below
<hello>hi there!</hello>
I tried using CSS
hello{
color:red;font-family:arial;
}
The above code works
I have used the above and also can add CSS. is there any harm of doing this, or the CSS features these won't support?
This is purely out of curiosity so don't suggest CSS edits or solutions please.
Why you can't make up elements
It is not valid HTML. Therefore how it behaves will be unpredictable.
It may work in some browsers, currently, but if any of your users visit your site on a different browser, they may get a totally different experience. Further to that, support could be dropped, or change at any time without warning.
Other options for custom elements
It is actually possible to define your own Document Type Definition (DTD), however that too is not a good idea.
Your best bet is to either stick with normal, well-supported HTML elements (see here for list of valid elements), or to use a web component framework, such as Vue, Angular or React, for custom elements/ components.
Don't forget, that you can add the class attribute (as well as others) to any element for styling, so for your use-case, there isn't any need to have additional elements.
This question already has answers here:
How can I write 'a:hover' in inline CSS?
(24 answers)
Closed 1 year ago.
Is it possible to create inline pseudo styles?
For instance, can I do something like the following?
Coding Horror
The reason behind this is I'm developing a .NET library that creates UI elements. I want to produce HTML elements that can have their hover state set without the use of an external style sheet.
Unfortunately no, you can't implement hover effects using inline CSS.
A (poor) work-around for this problem is to have your controls render style blocks when they are rendered. For example, your control could render as:
<style type="text/css">
.custom-class { background-color:green; }
.custom-class:hover { background-color:Red; }
</style>
Coding Horror
If you could force your users to drop a "style control" at the top of their pages you could render all your custom classes there instead of rendering them next to each control, which would be a very, very bad thing (browsers will restart rendering every time they come across a style block, having a lot of style blocks scattered around your page will cause slow rendering).
Unfortunately there's no elegant solution to this problem.
This is kind of a Catch-22 situation.
On one hand, you can add a style block right before where your element is inserted into the page, but Chris Pebble points out the problems with that. (If you decide on this, make sure you pick unique IDs for your Elements so your selectors don't accidentally select or style anything else).
On the other hand, you could do something like this:
...
But, that's nasty in its own right as it ties together markup, presentation, behavior, and a whole bunch of other things.
You could also inject a stylesheet into the page by writing out a link tag or manipulating document.stylesheets, but that's going to trigger a download.
I've usually seen the first method (adding a style block) done on large. "Modular" portal sites do this sort of thing, so maybe it's the de-facto standard (it is at least more readable and maybe easier to maintain than cramming JavaScript in there?). The JavaScript method seems to have the least impact on the DOM and the overall page as you're keeping your presentation to yourself.
This is one of those front-end dev morasses where every answer you choose is wrong to some extent, so weigh the options and pick what's easiest for you to build and maintain.
I would dynamically create a CSS file as I parse all the controls, and I would add a server side attribute to the controls that contained the hover or other pseudoclass styles.
<a style="color:blue" styleHover="color:blue" id="a1">Click!</a>
Your code can look for these attributes and generate a css file on the fly
#a1:hover {
color:blue
}
I don't know if .NET allows for you to do this type of parsing of the attributes, but I do something similar in a framework I created for php.
Hacss effectively brings pseudo-selectors to inline styles.
You could send a static stylesheet with the built page that uses css variables to control specific states and generate those in your script. Sadly you have to do this for every state and property you want to use.
* {
background-color: var(--n-background-color);
}
:hover {
background-color: var(--hover-background-color);
}
Coding Horror
To avoid using !important we cannot define the normal state inline directly.
Or you can use jQuery's hover function and set the background color.
I tried to find resources about 'alert' element, but nothing came out.
<alert type="success">Your message</alert>
But I can use it without issue. How can I apply CSS styles to different alert's type?
You look like you are trying to use Bootstrap's 'alert' classes (e.g. 'success').
http://getbootstrap.com/components/#alerts
The only way to make that a semantic element like <alert /> that I know of is something like AngularJS: http://angular-ui.github.io/bootstrap/#/alert
In this case, it is all styled by Bootstrap, or whatever Bootstrap theme you are using.
First there is not an HTML tag alert. you can create an alert with javascript.
You cannot add style to an alert as it is produced by the browser by default.
Have a look to this post:
How do I style the alert box with CSS?
W3C is always a very credible source for HTML syntax.
http://www.w3.org/TR/html-markup/Overview.html#toc
Now for where you heard about an <alert> element I have no idea. Never heard of it, but that does not mean it does not exist. W3C does not have it in this "complete set of HTML elements". It may be an element something other than HTML
As far as I know, and as some others have pointed out, there is no alert element in HTML.
However, you can use it. To allow for the HTML evolution, any modern browser will accept happily any unkown element.
I am not saying it is a good practice to use whatever name you want for an element. I am saying that the browsers will accept it.
About giving it format, use standard practices. Give it a class, or an id, and reference that in the CSS. No problem .
Technically there is a tag but its for html5 and its not completly supported,There is a table at the end of this article that shows browser compatibility.
hope this is informative:
Native Popups and Modals With the HTML5 “dialog” Element
You could use Alertify.
It has pretty decent customization options.
As someone who is beginning to make a transition from table based design to full CSS I'm wondering if using the style attribute to make adjustments to elements is considered "cheating" and if absolutely ALL presentation should be strictly in the style sheet?
See also:
A question of style - approaches to styling and stylesheets
There are cases where you know for sure that all you want to do is tweak the style of this one specific element, and nothing else.
In those cases you can happily use an inline style attribute. But then, at some point in the future, you'll realise that in fact you need to apply the same style to something else, and you'll realise you were wrong.
Been there, done that. 8-)
I feel there's an aspect that has not been touched upon here: the distinction between hand-edited HTML snippets and generated HTML snippets.
For human editing, it's probably better and easier to maintain to have the styles in a file.
However
As soon as you start generating HTML elements, with server-side scripts or with some kind of JavaScript, be sure to make all styles required for basic functionality inline!
For example, you wrote some kind of JavaScript library that generates tooltips. Now, you will inject DIVs into your page, that will need some styles. For example, position: absolute and, initially, display:none. You may be tempted to give these elements the class .popup and require that this class has the correct definitions in some CSS file. After all, styles should be specified in the CSS file, right?
You will make your JavaScript library very annoying to reuse, because you can no longer simply copy and invoke one .js file and be done with it. Instead, you will have to copy the .js file, but also have to make sure that all styles required by the script are defined in your CSS file, and you have to go hunting for those, and make sure their names don't conflict with classes you already have.
For maximum ease of use, just go ahead and set the required styles directly on the element as you create it. For styles that are purely for aesthetical purposes, such as background-color, font-size and such, you can still attach a class, to give the consumer of your script an easy way to change the appearance of your script elements, but don't require it!
You can use the style attribute, but the point of using CSS is that you make a change in a single file, and it affects the entire site. Try to avoid it as much as possible (old habits die hard)
It's not maintainable. All of us have done it. What you're best to do is put every adjustment into a style. Let me teach you something most developers do not know about CSS ... you can use N styles at a time.
For example, imagine you have a great style for colorized divs called someDIVStyle:
.someDIVStlye
{
background-color: yellow;
...
}
You want to use it, but just want to adjust the background-color to blue. Many people would copy/paste it and then make a new style with the change. However, simple create a style like this:
.blueBackground
{
background-color: blue;
}
Apply it as such:
<div class="someDIVStyle blueBackground">...
The style furthest to the right always overrides the properties of the styles preceding it. You can use a number of styles at once to meet your needs.
I agree with some other posters that it is best to keep the style information in the stylesheet. CSS tends to get complicated quickly, and it is nice to have that information in one place (rather than having to jump back and forth from HTML to stylesheet to see what styles are being used).
A little off-topic tip: Pressing F12 in IE8 brings up a great tool that lets you inspect the styles of elements in web pages you're browsing. In Firefox, FireBug does the same thing. Those kinds of tools are lifesavers if you want to know how a style change will affect an element.
It's a very "personal" question, to me the word "ALL" is a very strong word. You should do your best to have most of the styling in your css. but you can use style occetionally if it makes your life easier.
Generally it is best to have styles on the style sheet especially if it will be used multiple times, but using the style attribute is definitely not "cheating". A quick look through the stackoverflow source shows many examples of this.
Yes, it's kind of cheating, but it's up to you if you want to cheat a little. :)
The fundamental idea of having the styles in a style sheet is to separate the content from the layout. If you use the style attribute you are still mixing layout within the content.
However It's not that terrible, as you can quite easily move the style into a class. It's quite handy during development to be able to set a style on a specific element so easily without having to make up a class name and worry how the style will cascade.
I sometimes let the style attribute go through in the production code, if it's something that is specific for just one page, and if it's doubtful that it will be there for long. Occationally just because I am pressed for time, and it can be cleaned up later on...
So, even if you use a style attribute sometimes, you should still have the ambition that all the styles should be in a style sheet. In the long run it makes the code easier to maintain.
As others have said, in general, no.
However, there are cases where it makes perfect sense. For example, today I had to load an random background image into a div, from a directory with an unknown # of files. Basically, the client can drop files into that folder and they'll show up in the random background image rotation.
To me, this was a clear reason to dynamically build up the style tag on the div.
In addition, if you're using, for example, the .net framework with webforms and built-in controls then you'll see inline styles used anyway!
There can be very good reasons to put style information in a specific page.
For example, if you want to have a different header background on every page (travel agencies...), it is far easier to put that style information in that specific element (better, in the head of the document...) than to give that element a different class on every page and define all those classes in an external style-sheet.
The style attribute does have one important use: setting style programmatically. While the DOM includes methods to manipulate style sheets, support for them is still spotty and they're a bit heavyweight for many tasks, such as hiding and showing elements.
Yes, the style attribute is frowned upon in general. Since you're moving to the CSS method from table-based, I'd strongly recommend that you avoid inline styles. As a previous poster pointed out: bad habits are hard to break and getting into the habit of using inline styles for their temporary convenience is a mistake. You might as well go back to using the font tag. There's really no difference.
Having said that, there are occasions where it makes sense to use a simple inline style, but first develop the habit of using stylesheets. Only when you're comfortable with putting everything in a stylesheet should you start looking at shortcuts.
I think that's the general consensus of everyone who posted an answer
I have a website in which I provide tool-tips for certain things using a hidden <span> tag and JavaScript to track various mouse events. It works excellently. This site somewhat caters towards people with vision issues, so I try to make things degrade as well as possible if there is no JavaScript or CSS and generally I would say that it is successful in this regard.
So my question is, is it possible for these <span> to only exist if CSS is being used? I have thought about writing out the tool-tips in JavaScript on document load. But I was wondering if there is a better solution.
Perhaps you need to re-think the way you are providing tooltips. Could the content be contained in the title attribute of a semantically appropriate element?
EDIT: If you provide more info, someone might be able to suggest more of a solution. What sorts of elements are the tooltips popping up on? Images? Would the abbreviation tags be appropriate?
Quick Solution I just came up with: <span> has access to the core attributes, which include title, so you could include the tooltip text in the title, and use a javascript library like jQuery to display tooltips for all spans with a title.
A quick hack would be to color the text the same as the background (say, white on white) in html, and then use CSS to change the color back to something visible (black on white). Of course, this is only relevant for people able to see the text. Screen readers and such wouldn't see the text as hidden.
CSS is also used by screenreaders to help define which page elements are read or not.
Screen readers will almost always ignore elements with display:none applied to them, so not using CSS is not a valid indicator of a screenreader's presence.
I would go with Chris' idea of using javascript to generate the tooltips based on a title (or alt) attribute.
You could use JS to ensure that tooltips are only displayed when valid styles are set, so if JS is enabled and CSS disabled you can treat the extra information differently (eg footnotes).
http://juicystudio.com/article/screen-readers-display-none.php
http://www.456bereastreet.com/archive/200711/screen_readers_sometimes_ignore_displaynone/