Reset css property value ? - html

I have a page which uses a css file which has
html
{
width:100%;
}
However when that page in Iframe - it causes x-scroll.
But - If I remove the width attribute ( via chrome developer toolbar) OR set an invalid value like '' - it's getting fine :
Question :
Is it Ok to do this : ( in order to reset the value)
<head >
/*The original css file - I dont want to touch it*/
<link href="<%= ResolveUrl("~/Css/style.css") %>" rel="stylesheet" type="text/css" />
<style type="text/css">
html
{
width: '' !important;
}
</style>
p.s.
No js solutions please.

In order to reset that value you have to use the default one for width:
html
{
width:auto;
}
Also is not necessary to use the !important declaration.

Related

create switch for changing theme intead of browser page style html

I added a theme in my HTML page by:
<link rel="alternate stylesheet" href="css/dark.css" title="dark">
this creates an option to switch theme from view>style in browser as it is expected to. I want to create a switch in the page itself for changing the theme. <button>Switch Theme</button>will create a button but how do I make it switch theme?
You should trigger a change in the href attribute of the <link> tag on the click of the button, as demonstrated:
HTML
<link rel="stylesheet" href="dark.css" id="theme">
<button id="switch">Switch Theme</button>
JavaScript
document.getElementById('switch').onclick = function() {
if (document.getElementById('theme').href == "dark.css") {
document.getElementById('theme').href = "light.css";
} else {
document.getElementById('theme').href = "dark.css";
}
};
Now, the dark.css and light.css would contain different styles for your elements for both the themes respectively. For example:
dark.css
body{
background: #000;
}
light.css
body{
background: #fff;
}
this is very simple you need to bind the click to function and call it:
Replacing css file on the fly (and apply the new style to the page)

Use <a> to trigger a change in style

I currently am trying to change the style of my page on the push of a button - the button is part of a dropdown. Everything I try does not seem to work,
here is what I'm trying:
Lead</li>
Have two <link /> tags defined like this:
<link rel="stylesheet" href="default.css" />
<link rel="stylesheet" href="onclick.css" disabled id="onclick" />
<link rel="stylesheet" href="offclick.css" disabled id="offclick" />
Using the jQuery, you can easily give the control to the following HTML:
Change Style
$(function () {
$("#style-change").click(function () {
if ($("#onclick").prop("disabled")) {
$("#onclick").prop("disabled", false);
$("#offclick").prop("disabled", true);
} else {
$("#onclick").prop("disabled", true);
$("#offclick").prop("disabled", false);
}
});
});
Hope this helps.
To begin with this line of code looks scary !
Lead</li>
If you want to change the style for a particular container ? or change the entire stylesheet ?
If later is the case, then you need to hold the current stylesheet value somewhere, may be in ViewBag or even Session. And then check when you are including in your layout, something on this lines..
#if(ViewBag.Style == "red")
{
Styles.Render("~Views/Customer/css/Hide.css");
}
else if(ViewBag.Style == "blue")
{
// you get the idea...
}
If you're willing to use JQuery you can do this within one line:
$("head").append("<link rel='stylesheet' id='extracss' href='"~Views/Customer/css/Hide.css"' type='text/css' />");

How can I change css stylesheet with dart?

I'm working on a project for an exam and I need to change the stylesheet's name in the page. How can I do this with Dart?
I've seen that I can edit every attribute of my css from Dart but I've already made others css that I would like to use in my page.
For example, I have this in my html page:
<link href="stile.css" rel="stylesheet" type="text/css">
I need to edit the page to make this
<link href="stile-blu.css" rel="stylesheet" type="text/css">
How can I do this?
Assuming your <link ...> element is in the <head> element
document.querySelector('#button').onClick.listen((_) {
var stile = document.head.querySelector('link[href="stile.css"]');
stile.attributes['href'] = 'stile-blu.css';
});
If you add an id attribute to your link element the selector can be simplified
<link id="mystyle" href="stile.css" rel="stylesheet" type="text/css">
document.querySelector('#button').onClick.listen((_) {
var stile = document.head.querySelector('#mystyle');
stile.attributes['href'] = 'stile-blu.css';
});

Placeholder attribute on text input with iOS 6 from landscape to portrait

I have a problem after updating to iOS 6 that is driving me nuts.
It looks like any time I have the attribute "placeholder" on an input field, while rotating from
Portrait to Landscape and back to Portrait again the page shifts some pixels on the left side causing a horizontal bar.
I concluded after long research that it has to be something related to the meta viewport because every time I use the content="width=device-width" all works fine.
P.S Yes I really need to have a percent width on the input so as to have liquid design:)
Here is the example to recreate the issue. Thanks...
<html>
<head>
<title>test</title>
<meta content="width=device-width, initial-scale=1, maximum-scale=1" name="viewport"/>
</head>
<body>
<div style="width:100%;background-color:red">
<input id="testInput" placeholder="test" style="width:90%;" />
</div>
</body>
</html>
Applying "overflow: hidden;" on the containing element solved this issue for me.
I found this problem.
and fix it.
(URL : http://mooki83.tistory.com/2656550 (in korean))
testURL : http://mooki83.da.to/m/testios6.html
javascript :
/* Optimized PLACEHOLDER for iOS6 - Mooki ( http://mooki83.tistory.com ) */
$(document).ready(function(){
$(window).bind("orientationchange.fm_optimizeInput", fm_optimizeInput);
});
function fm_optimizeInput(){
$("input[placeholder],textarea[placeholder]").each(function(){
var tmpText = $(this).attr("placeholder");
if ( tmpText != "" ) {
$(this).attr("placeholder", "").attr("placeholder", tmpText);
}
})
}
CSS fix:
body>div {
overflow-y: auto;
}
Non js answer
Add overflow:hidden to parent element
and it will work like a charm

Inputting a default image in case the src attribute of an html <img> is not valid?

Is there any way to render a default image in an HTML <img> tag, in case the src attribute is invalid (using only HTML)? If not, what would be your lightweight way to work around it?
You asked for an HTML only solution...
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
<title>Object Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<p>
<object data="https://stackoverflow.com/does-not-exist.png" type="image/png">
<img src="https://cdn.sstatic.net/Img/unified/sprites.svg?v=e5e58ae7df45" alt="Stack Overflow logo and icons and such">
</object>
</p>
</body>
</html>
Since the first image doesn't exist, the fallback (the sprites used on this web site*) will display. And if you're using a really old browser that doesn't support object, it will ignore that tag and use the img tag. See caniuse website for compatibility. This element is widely supported by all browsers from IE6+.
* Unless the URL for the image changed (again), in which case you'll probably see the alt text.
This works well for me. Maybe you wanna use JQuery to hook the event.
<img src="foo.jpg" onerror="if (this.src != 'error.jpg') this.src = 'error.jpg';" alt="add alternative text here">
Updated with jacquargs error guard
Updated: CSS only solution
I recently saw Vitaly Friedman demo a great CSS solution I wasn't aware of. The idea is to apply the content property to the broken image. Normally :after or :before do not apply to images, but when they're broken, they're applied.
<img src="nothere.jpg" alt="add alternative text here">
<style>
img:before {
content: ' ';
display: block;
position: absolute;
height: 50px;
width: 50px;
background-image: url(ishere.jpg);
}
</style>
Demo: https://jsfiddle.net/uz2gmh2k/2/
As the fiddle shows, the broken image itself is not removed, but this will probably solve the problem for most cases without any JS nor gobs of CSS. If you need to apply different images in different locations, simply differentiate with a class: .my-special-case img:before { ...
Found this solution in Spring in Action 3rd Ed.
<img src="../resources/images/Image1.jpg" onerror="this.src='../resources/images/none.jpg'" />
Update:
This is not an HTML only solution... onerror is javascript
a simple img-element is not very flexible so i combined it with a picture-element. this way no CSS is needed. when an error occurs, all srcset's are set to the fallback version. a broken link image is not showing up. it does not load unneeded image versions. the picture-element supports responsive design and multiple fallbacks for types that are not supported by the browser.
<picture>
<source id="s1" srcset="image1_not_supported_by_browser.webp" type="image/webp">
<source id="s2" srcset="image2_broken_link.png" type="image/png">
<img src="image3_fallback.jpg" alt="" onerror="this.onerror=null;document.getElementById('s1').srcset=document.getElementById('s2').srcset=this.src;">
</picture>
Simple and neat solution involving some good answers and comment.
<img src="foo.jpg" onerror="this.src='error.jpg';this.onerror='';">
It even solve infinite loop risk.
Worked for me.
<style type="text/css">
img {
background-image: url('/images/default.png')
}
</style>
Be sure to enter dimensions of image and whether you want the image to tile or not.
I don't think it is possible using just HTML. However using javascript this should be doable. Bassicly we loop over each image, test if it is complete and if it's naturalWidth is zero then that means that it not found. Here is the code:
fixBrokenImages = function( url ){
var img = document.getElementsByTagName('img');
var i=0, l=img.length;
for(;i<l;i++){
var t = img[i];
if(t.naturalWidth === 0){
//this image is broken
t.src = url;
}
}
}
Use it like this:
window.onload = function() {
fixBrokenImages('example.com/image.png');
}
Tested in Chrome and Firefox
<img style="background-image: url(image1), url(image2);"></img>
Use background image that let you add multiple images.
My case:
image1 is the main image, this will get from some place (browser doing a request)
image2 is a default local image to show while image1 is being loaded.
If image1 returns any kind of error, the user won't see any change and this will be clean for user experience
If you're using Angular/jQuery then this might help...
<img ng-src="{{item.url}}" altSrc="{{item.alt_url}}" onerror="this.src = $(this).attr('altSrc')">
Explanation
Assuming that item has a property url that might be null, when it is then the image will show up as broken. That triggers execution of onerror attribute expression, as described above. You need to override the src attribute as described above, but you will need jQuery to access your altSrc. Couldn't get it to work with vanilla JavaScript.
Might seem a little hacky but saved the day on my project.
angular2:
<img src="{{foo.url}}" onerror="this.src='path/to/altimg.png'">
An HTML only solution, where the only requirement is that you know the size of the image that you're inserting. Will not work for transparent images, as it uses background-image as a filler.
We can successfully use background-image to link the image that appears if the given image is missing. Then the only problem is the broken icon image - we can remove it by inserting a very big empty character, thus pushing the content outside the display of img.
img {
background-image: url("http://placehold.it/200x200");
overflow: hidden;
}
img:before {
content: " ";
font-size: 1000px;
}
This image is missing:
<img src="a.jpg" style="width: 200px; height: 200px"/><br/>
And is displaying the placeholder
An CSS only solution (Webkit only)
img:before {
content: " ";
font-size: 1000px;
background-image: url("http://placehold.it/200x200");
display: block;
width: 200px;
height: 200px;
position: relative;
z-index: 0;
margin-bottom: -16px;
}
This image is there:
<img src="http://placehold.it/100x100"/><br/>
This image is missing:
<img src="a.jpg"/><br/>
And is displaying the placeholder
Update: 2022 (works on chrome still!!)
I recently had to build a fall back system which included any number of fallback images. Here's how I did it using a simple JavaScript function.
HTML
<img src="some_image.tiff"
onerror="fallBackImg(this);"
data-src-1="some_image.png"
data-src-2="another_image.jpg">
JavaScript
function fallBackImg(elem){
elem.error = null;
let index = elem.dataset.fallIndex || 1;
elem.src = elem.dataset[`src-${index}`];
elem.dataset.fallIndex = ++index;
}
I feel like it's a pretty lightweight way of handling many fallback images.
If you want "HTML only" then this
<img src="some_image.tiff"
onerror="this.error = null;
let i = this.dataset.i || 1;
this.src = this.dataset[`src-${i}`];
this.dataset.i = ++i;"
data-src-1="some_image.png"
data-src-2="another_image.jpg">
A modulable version with JQuery, add this at the end of your file:
<script>
$(function() {
$('img[data-src-error]').error(function() {
var o = $(this);
var errorSrc = o.attr('data-src-error');
if (o.attr('src') != errorSrc) {
o.attr('src', errorSrc);
}
});
});
</script>
and on your img tag:
<img src="..." data-src-error="..." />
There is no way to be sure the myriad number of clients (browsers) that will try to view your page. One aspect to consider is that email clients are defacto web browsers and may not handle such trickamajickery ...
As such you should ALSO include an alt/text with a DEFAULT WIDTH and HEIGHT, like this. This is a pure HTML solution.
alt="NO IMAGE" width="800" height="350"
So the other good answer would be slightly modified as follows:
<img src="foo.jpg" onerror="if (this.src != 'error.jpg') this.src = 'error.jpg';" alt="NO IMAGE" width="800" height="350">
I had issues with the object tag in Chrome, but I would imagine this would apply to that as well.
You can further style the alt/text to be VERY BIG ...
So my answer is use Javascript with a nice alt/text fallback.
I also found this interesting: How to style an image's alt attribute
React
<img
src="https://example.com/does_not_exist.png"
onError={(e) => {
e.currentTarget.src = "https://example.com/default.png"
}}
/>
The above solution is incomplete, it missed the attribute src.
this.src and this.attribute('src') are NOT the same, the first one contains the full reference to the image, for example http://my.host/error.jpg, but the attribute just keeps the original value, error.jpg
Correct solution
<img src="foo.jpg" onerror="if (this.src != 'error.jpg' && this.attribute('src') != 'error.jpg') this.src = 'error.jpg';" />
3 solutions for this:
Consider following html file:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<img id="imageId">
<script src="setimage.js"></script>
</body>
</html>
Solution one :
reference this block of JS code inside the body tag of your html as
<script src="setimage.js"></script>
and set the src paths, the first is the one if there is an error, the next is the one you hope works first time :)
var img = document.getElementById("imageId")
img.onerror = () => {
img.src= "../error.png";
}
img.src= "../correct.webp.png";
Solution two:
this solution is almost the same, instead you will call the method, again at the end of your body within a script tag, but would supply the paths there.
function setImageWithFallback(mainImgPath, secondaryImgPath) {
var img = document.getElementById("imageId")
img.onerror = () => {
img.src= mainImgPath;
}
img.src= secondaryImgPath;
}
Solution three:
if its just a single image, this would be the simplest :) simply set the onerror at the img tag
<img id="imageId" src="../correct.webp.png"
onerror="if (this.src != '../error.png') this.src = '../error.png';">
If you are using Angular 1.x you can include a directive that will allow you to fallback to any number of images. The fallback attribute supports a single url, multiple urls inside an array, or an angular expression using scope data:
<img ng-src="myFirstImage.png" fallback="'fallback1.png'" />
<img ng-src="myFirstImage.png" fallback="['fallback1.png', 'fallback2.png']" />
<img ng-src="myFirstImage.png" fallback="myData.arrayOfImagesToFallbackTo" />
Add a new fallback directive to your angular app module:
angular.module('app.services', [])
.directive('fallback', ['$parse', function ($parse) {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var errorCount = 0;
// Hook the image element error event
angular.element(element).bind('error', function (err) {
var expressionFunc = $parse(attrs.fallback),
expressionResult,
imageUrl;
expressionResult = expressionFunc(scope);
if (typeof expressionResult === 'string') {
// The expression result is a string, use it as a url
imageUrl = expressionResult;
} else if (typeof expressionResult === 'object' && expressionResult instanceof Array) {
// The expression result is an array, grab an item from the array
// and use that as the image url
imageUrl = expressionResult[errorCount];
}
// Increment the error count so we can keep track
// of how many images we have tried
errorCount++;
angular.element(element).attr('src', imageUrl);
});
}
};
}])
Using Jquery you could do something like this:
$(document).ready(function() {
if ($("img").attr("src") != null)
{
if ($("img").attr("src").toString() == "")
{
$("img").attr("src", "images/default.jpg");
}
}
else
{
$("img").attr("src", "images/default.jpg");
}
});
For any image, just use this javascript code:
if (ptImage.naturalWidth == 0)
ptImage.src = '../../../../icons/blank.png';
where ptImage is a <img> tag address obtained by document.getElementById().
Google threw out this page to the "image fallback html" keywords, but because non of the above helped me, and I was looking for a "svg fallback support for IE below 9", I kept on searching and this is what I found:
<img src="base-image.svg" alt="picture" />
<!--[if (lte IE 8)|(!IE)]><image src="fallback-image.png" alt="picture" /><![endif]-->
It might be off-topic, but it resolved my own issue and it might help someone else too.
In addition to Patrick's brilliant answer, for those of you who are searching for a cross-platform angular js solution, here you go:
<object type="image/png" data-ng-attr-data="{{ url || 'data:' }}">
<!-- any html as a fallback -->
</object>
Here's a plunk where I was playing trying to find the right solution: http://plnkr.co/edit/nL6FQ6kMK33NJeW8DVDY?p=preview
If you have created dynamic Web project and have placed the required image in WebContent then you can access the image by using below mentioned code in Spring MVC:
<img src="Refresh.png" alt="Refresh" height="50" width="50">
You can also create folder named img and place the image inside the folder img and place that img folder inside WebContent then you can access the image by using below mentioned code:
<img src="img/Refresh.png" alt="Refresh" height="50" width="50">
I am adding loading="lazy" to img tag. In some cases it works..
here is a simple Jquery that worked for me
$(image).on('error', function(event) {
imgage.attr('src', 'your_image.png');})
Well!!
I found this way convenient , check for the height attribute of image to be 0, then you can overwrite the src attribute with default image:
https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement/Image
image.setAttribute('src','../icons/<some_image>.png');
//check the height attribute.. if image is available then by default it will
//be 100 else 0
if(image.height == 0){
image.setAttribute('src','../icons/default.png');
}