I am working on asp.net webforms. I am displaying a asp:RegularExpressionValidator in a <td> element which validates entry in a textbox. When the page loads, it is displayed as a <span> element with visibility:hidden. The problem is that in Firefox, it still occupies space, which doesn't happen in IE and Chrome. Because of this the html is not displayed properly in Firefox. Is there any solution for this?
"Visibility: hidden;" renders the element but keeps it invisible.
If you intend not to load the element, you should use
.someElement { display: none; }
This would not even reserve the space for the specified element.
Hope this helps..
You should try display:none instead of visibility:hidden.
display:none means that the tag in question will not appear on the page at all (although you can still interact with it through the dom). There will be no space allocated for it between the other tags.
I'd recommend a different approach... I know that code depends on asp.net... I presume the thing you don't want is to have a bigger spacing because of those validators, or you don't want the layout to be expanding on error highlight, considering that, I'd suggest:
Make all validator messages having position absolute (I hope you have a container for each field, that one needs to have position: relative)
As each validator have absolute position, won't take more vertical space (it's better to add the code via a css class, which should have something like:
.validatorMessage {
position: absolute;
left:0;
top: 2rem /* should be the height of the field */
}
The only issue is, when those messages fires up, will shorten the available space, but I think is a reasonable tradeoff.
Hope this can help
I have HTML like below and all is displaying grand, the problem is that due to a problem with Sharepoint 2013's editor your unable to edit the link text but as soon as I remove display: block I can edit the link text, the same happens using float.
My question is there a way to emulate the affect of display: block where it will span the whole width that is available to it without using display or float?
<div class="button">
Link Text
</div>
There is one option to make an inline element to be like a block by using position:absolute without using display or float.
But I hope absolute positioning doesn't fit your want. Thus, the final conclusion is that you must use display or float property to render it correctly.
If you even use absolute then don't forget to keep position:relative to your parent element from which you want to be the element as absolute.
You could try display: inline-block; width: 100%;. You might need to alter the width to take into account any padding or border you've set.
(In the past I've used an edit mode panel and other tricks, so these hacky styles only apply when the page is being edited.)
SharePoint 2013's editor is so utterly awesome isn't it? :-(
I have a form of width 450px with one item that has to take the full page's width (990px).
position:absolute is a problem because this wide item needs to fit in the flow of elements inside the form. margin-left:-270px seems a bit hackish and likely to break down with future rule changes. Is there a better solution?
How can I get an element in the form's flow that takes up the whole page's width?
If you're using fixed width layouts, I don't really see a margin-left of -270 as being hackish. If you hadn't posted it yourself, it would be the answer I would suggest.
To make it seem less hackish, an alternative might be to use Less - it's effectively a CSS based language that compiles to plain CSS. You could then specify the rule so that changes to the form or page width will automatically sort out your margin also:
#page_width: 990px;
#form_width: 450px;
...
.full_width_form_element {
margin-left: (#form_width - #page_width) / 2;
}
http://lesscss.org/
Use the overflow property of CSS. overflow: auto to cause scrolling, overflow: visible to allow it to leak out of the box. overflow: hidden to hide whatever part of it leaks outside the box.
I am new to CSS, so please bear with me. I have this form which I'm trying to style. Everything works fine, except the confirmation label which is in a div. I want some space to be there between div.field, and while this works for all the input elements, it doesn't work for the label message which is at the bottom. I tried increasing margin-top, but to no avail. I would like that element to be positioned in the center.
Using the web-developer addon of Firefox, it shows me that the width and height of div.field of label tag specifically is 284px and 209px respectively. Why is this so, when I haven't set it that way?
You can view the code live at jsfiddle: http://www.jsfiddle.net/yMHJY/
The solution is simple, really. Add a margin-top to the parent of the label element, and add overflow: hidden to the div#contact div .field selector.
However, can I just say that the code can be rewritten for much better efficiency and semantic correctness. For instance, I would contain the last massage in a p tag and not a label in a div. Also, I would have each input element placed in an unordered list ul instead of divs. You also have a lot of unnecessary floats and the br at the end of each input is wholly uneeded. Oh, and unless you are embedding Calluna somehow, don't use it - stick to web safe fonts (and if you are, you still need to suggest an alternative, in the user's browser does not support it, and also to give the browser something to display while the font loads).
Edit
Fixed the load for ya, I should be paid for this kind of stuff :) Just stick to better HTML and CSS next time.
http://www.jsfiddle.net/SNrtA/
To center you could add a parent container
<div id="parent">
<label id="label">Your Message Has Been Sent</label>
</div>
div#parent {
text-align:center;
}
or add an id to your original parent div to target it with above css
with regards to the margin, you seem to have an issue with a float:left being set in the
div#contact div input[type=text] class. You need to clear this as it could be causing you margin problems. Try removing this and amending your styles. Why are you floating the inputs left?
The CSS rules visibility:hidden and display:none both result in the element not being visible. Are these synonyms?
display:none means that the tag in question will not appear on the page at all (although you can still interact with it through the dom). There will be no space allocated for it between the other tags.
visibility:hidden means that unlike display:none, the tag is not visible, but space is allocated for it on the page. The tag is rendered, it just isn't seen on the page.
For example:
test | <span style="[style-tag-value]">Appropriate style in this tag</span> | test
Replacing [style-tag-value] with display:none results in:
test | | test
Replacing [style-tag-value] with visibility:hidden results in:
test | | test
They are not synonyms.
display:none removes the element from the normal flow of the page, allowing other elements to fill in.
visibility:hidden leaves the element in the normal flow of the page such that is still occupies space.
Imagine you are in line for a ride at an amusement park and someone in the line gets so rowdy that security plucks them from the line. Everyone in line will then move forward one position to fill the now empty slot. This is like display:none.
Contrast this with the similar situation, but that someone in front of you puts on an invisibility cloak. While viewing the line, it will look like there is an empty space, but people can't really fill that empty looking space because someone is still there. This is like visibility:hidden.
One thing worth adding, though it wasn't asked, is that there is a third option of making the object completely transparent. Consider:
1st unseen link.<br />
2nd unseen link.<br />
3rd unseen link.
(Be sure to click "Run code snippet" button above to see the result.)
The difference between 1 and 2 has already been pointed out (namely, 2 still takes up space). However, there is a difference between 2 and 3: in case 3, the mouse will still switch to the hand when hovering over the link, and the user can still click on the link, and Javascript events will still fire on the link. This is usually not the behavior you want (but maybe sometimes it is?).
Another difference is if you select the text, then copy/paste as plain text, you get the following:
1st link.
2nd link.
3rd unseen link.
In case 3 the text does get copied. Maybe this would be useful for some type of watermarking, or if you wanted to hide a copyright notice that would show up if a carelessly user copy/pasted your content?
display:none removes the element from the layout flow.
visibility:hidden hides it but leaves the space.
There is a big difference when it comes to child nodes. For example: If you have a parent div and a nested child div. So if you write like this:
<div id="parent" style="display:none;">
<div id="child" style="display:block;"></div>
</div>
In this case none of the divs will be visible. But if you write like this:
<div id="parent" style="visibility:hidden;">
<div id="child" style="visibility:visible;"></div>
</div>
Then the child div will be visible whereas the parent div will not be shown.
They're not synonyms - display: none removes the element from the flow of the page, and rest of the page flows as if it weren't there.
visibility: hidden hides the element from view but not the page flow, leaving space for it on the page.
display: none removes the element from the page entirely, and the page is built as though the element were not there at all.
Visibility: hidden leaves the space in the document flow even though you can no longer see it.
This may or may not make a big difference depending on what you are doing.
With visibility:hidden the object still takes up vertical height on the page. With display:none it is completely removed. If you have text beneath an image and you do display:none, that text will shift up to fill the space where the image was. If you do visibility:hidden the text will remain in the same location.
display:none will hide the element and collapse the space is was taking up, whereas visibility:hidden will hide the element and preserve the elements space. display:none also effects some of the properties available from javascript in older versions of IE and Safari.
visibility:hidden preserves the space; display:none doesn't.
In addition to all other answers, there's an important difference for IE8: If you use display:none and try to get the element's width or height, IE8 returns 0 (while other browsers will return the actual sizes). IE8 returns correct width or height only for visibility:hidden.
display: none;
It will not be available on the page and does not occupy any space.
visibility: hidden;
it hides an element, but it will still take up the same space as before. The element will be hidden, but still, affect the layout.
visibility: hidden preserve the space, whereas display: none doesn't preserve the space.
Display None Example:https://www.w3schools.com/css/tryit.asp?filename=trycss_display_none
Visibility Hidden Example : https://www.w3schools.com/cssref/tryit.asp?filename=trycss_visibility
visibility:hidden will keep the element in the page and occupies that space but does not show to the user.
display:none will not be available in the page and does not occupy any space.
display: none
It will remove the element from the normal flow of the page, allowing other elements to fill in.
An element will not appear on the page at all but we can still interact with it through the DOM.
There will be no space allocated for it between the other elements.
visibility: hidden
It will leave the element in the normal flow of the page such that is still occupies space.
An element is not visible and Element’s space is allocated for it on the page.
Some other ways to hide elements
Use z-index
#element {
z-index: -11111;
}
Move an element off the page
#element {
position: absolute;
top: -9999em;
left: -9999em;
}
Interesting information about visibility: hidden and display: none properties
visibility: hidden and display: none will be equally performant since they both re-trigger layout, paint and composite. However, opacity: 0 is functionality equivalent to visibility: hidden and does not re-trigger the layout step.
And CSS-transition property is also important thing that we need to take care. Because toggling from visibility: hidden to visibility: visible allow for CSS-transitions to be use, whereas toggling from display: none to display: block does not. visibility: hidden has the additional benefit of not capturing JavaScript events, whereas opacity: 0 captures events
If visibility property set to "hidden", the browser will still take space on the page for the content even though it's invisible.
But when we set an object to "display:none", the browser does not allocate space on the page for its content.
Example:
<div style="display:none">
Content not display on screen and even space not taken.
</div>
<div style="visibility:hidden">
Content not display on screen but it will take space on screen.
</div>
View details
There are a lot of detailed answers here, but I thought I should add this to address accessibility since there are implications.
display: none; and visibility: hidden; may not be read by all screen reader software. Keep in mind what visually-impaired users will experience.
The question also asks about synonyms. text-indent: -9999px; is one other that is roughly equivalent. The important difference with text-indent is that it will often be read by screen readers. It can be a bit of a bad experience as users can still tab to the link.
For accessibility, what I see used today is a combination of styles to hide an element while being visible to screen readers.
{
clip: rect(1px, 1px, 1px, 1px);
clip-path: inset(50%);
height: 1px;
width: 1px;
margin: -1px;
overflow: hidden;
padding: 0;
position: absolute;
}
A great practice is to create a "Skip to content" link to the anchor of the main body of content. Visually-impaired users probably don't want to listen to your full navigation tree on every single page. Make the link visually hidden. Users can just hit tab to access the link.
For more on accessibility and hidden content, see:
https://webaim.org/techniques/css/invisiblecontent/
https://webaim.org/techniques/skipnav/
Summarizing all the other answers:
visibility
display
element with visibility: hidden, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), but still occupies space in the rendered markup
element with display:none, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), and DOES NOT occupy space in the rendered markup
css transitions can be applied for visibility changes
css transitions can not be applied on display changes
you can make a parent visibility:hidden but a child with visibility: visible would still be shown
when parent is display:none, children can't override and make themselves visible
part of the DOM tree (so you can still target it with DOM queries)
part of the DOM tree (so you can still target it with DOM queries)
part of the render tree
NOT part of the render tree
any reflow / layout in the parent element or child elements, would possibly trigger a reflow in these elements as well, as they are part of the render tree.
any reflow / layout in the parent element, would not impact these elements, as these are not part of the render tree
toggling between visibility: hidden and visible, would possibly not trigger a reflow / layout. (According to this comment it does: What is the difference between visibility:hidden and display:none? and possibly according to this as well https://developers.google.com/speed/docs/insights/browser-reflow)
toggling between display:none to display: (something else), would lead to a layout /reflow as this element would now become part of the render tree
you can measure the element through DOM methods
you can not measure the element or its descendants using DOM methods
If you have a huge number of elements using visibility: none on the page, the browser might hang while rendering, as all these elements require layout, even though they are not shown
If you have a huge number of elements using display:none, they wouldn't impact the rendering as they are not part of the render tree
Resources:
https://developers.google.com/speed/docs/insights/browser-reflow
http://www.stubbornella.org/content/2009/03/27/reflows-repaints-css-performance-making-your-javascript-slow/
Performance differences between visibility:hidden and display:none
Other Info:
There are some browser support idiosyncrancies as well, but they seem to apply to very old browsers, and are available in the other answers, so I have not discussed them here.
There are some other alternatives to hide element, like opacity, or absolute positioning off screen. All of them have been touched upon in some or the other answers, and have some drawbacks.
According to this comment (Performance differences between visibility:hidden and display:none), if you have a lot of elements using display:none and you change to display: (something else), it will cause a single reflow, while if you have multiple visibility: hidden elements and you turn them visible, it will cause reflow for each element. (I don't really understand this)
One other difference is that visibility:hidden works in really, really old browsers, and display:none does not:
https://www.w3schools.com/cssref/pr_class_visibility.asp
https://www.w3schools.com/cssref/pr_class_display.asp
The difference goes beyond style and is reflected in how the elements behave when manipulated with JavaScript.
Effects and side effects of display: none:
the target element is taken out of the document flow (doesn't affect layout of other elements);
all descendants are affected (are not displayed either and cannot “snap out” of this inheritance);
measurements cannot be made for the target element nor for its descendants – they are not rendered at all, thus their clientWidth, clientHeight, offsetWidth, offsetHeight, scrollWidth, scrollHeight, getBoundingClientRect(), getComputedStyle(), all return 0s.
Effects and side-effects of visibility: hidden:
the target element is hidden from view, but is not taken out of the flow and affects layout, occupying its normal space;
innerText (but not innerHTML) of the target element and descendants returns empty string.
As described elsewhere in this stack, the two are not synonymous. visibility:hidden will leave space on the page whereas display:none will hide the element entirely. I think it's important to talk about how this affects the children of a given element. If you were to use visibility:hidden then you could show the children of that element with the right styling. But with display:none you hide the children regardless of whether you use display: block | flex | inline | grid | inline-block or not.
display:none; will neither display the element nor will it allot space for the element on the page whereas visibility:hidden; will not display the element on the page but will allot space on the page.
We can access the element in DOM in both cases.
To understand it in a better way please look at the following code:
display:none vs visibility:hidden