For example,
(If) I have this 2d editor in HTML form:
and I have a css file named "filter" with code:
monochrome {
filter: grayscale(var(--value, 100%)); --value:100%;
}
What are the methods to apply the "monochrome" filter to the editor's Dragon when placing it(The dragon sprite) onto the canvas?
<link rel="stylesheet" type="text/css" href="monochrome.css">
if (data[Blocks].id === "dragon") {
*What should I write here in order to apply the css filter (only to the dragon sprite, when placing?*
}
The first step is turning the CSS monochrome definition into a class. This is simply done by prepending a dot prior the name e.g.
.monochrome {
filter: grayscale(var(--value, 100%));
}
Defining it this way makes it reusable by multiple HTML elements - as your Dragon might not be the only element which you want to apply the filter to.
As we have a CSS class now we can apply it to individual objects by calling either
theObject.classList.add("monochrome");
or
theObject.classList.remove("monochrome");
while add / remove as it's name implies adds or removes the CSS class given in quotes.
But how do we get a reference to theObject?
If you've given your HTML elements an unique id using it's id property it's quite easy:
document.getElementById("id")
Be careful though - it's something different than the id you've mentioned in your post.
Here's an example:
document.getElementById("monochromeButton").addEventListener("click", function() {
document.getElementById("dragon").classList.add("monochrome");
});
document.getElementById("removeButton").addEventListener("click", function() {
document.getElementById("dragon").classList.remove("monochrome");
});
.monochrome {
filter: grayscale(var(--value, 100%));
}
<button id="monochromeButton">
monochrome
</button>
<button id="removeButton">
remove filter
</button>
<br>
<img id="dragon" src="https://picsum.photos/id/237/200/140">
I have a link button inside a <td> which I have to disable. This works on IE but not working in Firefox and Chrome.
I tried all the following but not working on Firefox (using 1.4.2 js):
$(".myLink").attr('disabled', 'disabled');
$(".myLink").attr('disabled', true);
$(".myLink").attr('disabled', 'true');
Note - I cannot de-register the click function for the anchor tag as it is registered dynamically. AND I HAVE TO SHOW THE LINK IN DISABLED MODE.
You can't disable a link (in a portable way). You can use one of these techniques (each one with its own benefits and disadvantages).
CSS way
This should be the right way (but see later) to do it when most of browsers will support it:
a.disabled {
pointer-events: none;
}
It's what, for example, Bootstrap 3.x does. Currently (2016) it's well supported only by Chrome, FireFox and Opera (19+). Internet Explorer started to support this from version 11 but not for links however it's available in an outer element like:
span.disable-links {
pointer-events: none;
}
With:
<span class="disable-links">...</span>
Workaround
We, probably, need to define a CSS class for pointer-events: none but what if we reuse the disabled attribute instead of a CSS class? Strictly speaking disabled is not supported for <a> but browsers won't complain for unknown attributes. Using the disabled attribute IE will ignore pointer-events but it will honor IE specific disabled attribute; other CSS compliant browsers will ignore unknown disabled attribute and honor pointer-events. Easier to write than to explain:
a[disabled] {
pointer-events: none;
}
Another option for IE 11 is to set display of link elements to block or inline-block:
<a style="pointer-events: none; display: inline-block;" href="#">...</a>
Note that this may be a portable solution if you need to support IE (and you can change your HTML) but...
All this said please note that pointer-events disables only...pointer events. Links will still be navigable through keyboard then you also need to apply one of the other techniques described here.
Focus
In conjunction with above described CSS technique you may use tabindex in a non-standard way to prevent an element to be focused:
...
I never checked its compatibility with many browsers then you may want to test it by yourself before using this. It has the advantage to work without JavaScript. Unfortunately (but obviously) tabindex cannot be changed from CSS.
Intercept clicks
Use a href to a JavaScript function, check for the condition (or the disabled attribute itself) and do nothing in case.
$("td > a").on("click", function(event){
if ($(this).is("[disabled]")) {
event.preventDefault();
}
});
To disable links do this:
$("td > a").attr("disabled", "disabled");
To re-enable them:
$("td > a").removeAttr("disabled");
If you want instead of .is("[disabled]") you may use .attr("disabled") != undefined (jQuery 1.6+ will always return undefined when the attribute is not set) but is() is much more clear (thanks to Dave Stewart for this tip). Please note here I'm using the disabled attribute in a non-standard way, if you care about this then replace attribute with a class and replace .is("[disabled]") with .hasClass("disabled") (adding and removing with addClass() and removeClass()).
Zoltán Tamási noted in a comment that "in some cases the click event is already bound to some "real" function (for example using knockoutjs) In that case the event handler ordering can cause some troubles. Hence I implemented disabled links by binding a return false handler to the link's touchstart, mousedown and keydown events. It has some drawbacks (it will prevent touch scrolling started on the link)" but handling keyboard events also has the benefit to prevent keyboard navigation.
Note that if href isn't cleared it's possible for the user to manually visit that page.
Clear the link
Clear the href attribute. With this code you do not add an event handler but you change the link itself. Use this code to disable links:
$("td > a").each(function() {
this.data("href", this.attr("href"))
.attr("href", "javascript:void(0)")
.attr("disabled", "disabled");
});
And this one to re-enable them:
$("td > a").each(function() {
this.attr("href", this.data("href")).removeAttr("disabled");
});
Personally I do not like this solution very much (if you do not have to do more with disabled links) but it may be more compatible because of various way to follow a link.
Fake click handler
Add/remove an onclick function where you return false, link won't be followed. To disable links:
$("td > a").attr("disabled", "disabled").on("click", function() {
return false;
});
To re-enable them:
$("td > a").removeAttr("disabled").off("click");
I do not think there is a reason to prefer this solution instead of the first one.
Styling
Styling is even more simple, whatever solution you're using to disable the link we did add a disabled attribute so you can use following CSS rule:
a[disabled] {
color: gray;
}
If you're using a class instead of attribute:
a.disabled {
color: gray;
}
If you're using an UI framework you may see that disabled links aren't styled properly. Bootstrap 3.x, for example, handles this scenario and button is correctly styled both with disabled attribute and with .disabled class. If, instead, you're clearing the link (or using one of the others JavaScript techniques) you must also handle styling because an <a> without href is still painted as enabled.
Accessible Rich Internet Applications (ARIA)
Do not forget to also include an attribute aria-disabled="true" together with disabled attribute/class.
Got the fix in css.
td.disabledAnchor a{
pointer-events: none !important;
cursor: default;
color:Gray;
}
Above css when applied to the anchor tag will disable the click event.
For details checkout this link
Thanks to everyone that posted solutions (especially #AdrianoRepetti), I combined multiple approaches to provide some more advanced disabled functionality (and it works cross browser). The code is below (both ES2015 and coffeescript based on your preference).
This provides for multiple levels of defense so that Anchors marked as disable actually behave as such.
Using this approach, you get an anchor that you cannot:
click
tab to and hit return
tabbing to it will move focus to the next focusable element
it is aware if the anchor is subsequently enabled
How to
Include this css, as it is the first line of defense. This assumes the selector you use is a.disabled
a.disabled {
pointer-events: none;
cursor: default;
}
Next, instantiate this class on ready (with optional selector):
new AnchorDisabler()
ES2015 Class
npm install -S key.js
import {Key, Keycodes} from 'key.js'
export default class AnchorDisabler {
constructor (config = { selector: 'a.disabled' }) {
this.config = config
$(this.config.selector)
.click((ev) => this.onClick(ev))
.keyup((ev) => this.onKeyup(ev))
.focus((ev) => this.onFocus(ev))
}
isStillDisabled (ev) {
// since disabled can be a class or an attribute, and it can be dynamically removed, always recheck on a watched event
let target = $(ev.target)
if (target.hasClass('disabled') || target.prop('disabled') == 'disabled') {
return true
}
else {
return false
}
}
onFocus (ev) {
// if an attempt is made to focus on a disabled element, just move it along to the next focusable one.
if (!this.isStillDisabled(ev)) {
return
}
let focusables = $(':focusable')
if (!focusables) {
return
}
let current = focusables.index(ev.target)
let next = null
if (focusables.eq(current + 1).length) {
next = focusables.eq(current + 1)
} else {
next = focusables.eq(0)
}
if (next) {
next.focus()
}
}
onClick (ev) {
// disabled could be dynamically removed
if (!this.isStillDisabled(ev)) {
return
}
ev.preventDefault()
return false
}
onKeyup (ev) {
// We are only interested in disabling Enter so get out fast
if (Key.isNot(ev, Keycodes.ENTER)) {
return
}
// disabled could be dynamically removed
if (!this.isStillDisabled(ev)) {
return
}
ev.preventDefault()
return false
}
}
Coffescript class:
class AnchorDisabler
constructor: (selector = 'a.disabled') ->
$(selector).click(#onClick).keyup(#onKeyup).focus(#onFocus)
isStillDisabled: (ev) =>
### since disabled can be a class or an attribute, and it can be dynamically removed, always recheck on a watched event ###
target = $(ev.target)
return true if target.hasClass('disabled')
return true if target.attr('disabled') is 'disabled'
return false
onFocus: (ev) =>
### if an attempt is made to focus on a disabled element, just move it along to the next focusable one. ###
return unless #isStillDisabled(ev)
focusables = $(':focusable')
return unless focusables
current = focusables.index(ev.target)
next = (if focusables.eq(current + 1).length then focusables.eq(current + 1) else focusables.eq(0))
next.focus() if next
onClick: (ev) =>
# disabled could be dynamically removed
return unless #isStillDisabled(ev)
ev.preventDefault()
return false
onKeyup: (ev) =>
# 13 is the js key code for Enter, we are only interested in disabling that so get out fast
code = ev.keyCode or ev.which
return unless code is 13
# disabled could be dynamically removed
return unless #isStillDisabled(ev)
ev.preventDefault()
return false
Try the element:
$(td).find('a').attr('disabled', 'disabled');
Disabling a link works for me in Chrome: http://jsfiddle.net/KeesCBakker/LGYpz/.
Firefox doesn't seem to play nice. This example works:
<a id="a1" href="http://www.google.com">Google 1</a>
<a id="a2" href="http://www.google.com">Google 2</a>
$('#a1').attr('disabled', 'disabled');
$(document).on('click', 'a', function(e) {
if ($(this).attr('disabled') == 'disabled') {
e.preventDefault();
}
});
Note: added a 'live' statement for future disabled / enabled links.
Note2: changed 'live' into 'on'.
Bootstrap 4.1 provides a class named disabled and aria-disabled="true" attribute.
example"
<a href="#"
class="btn btn-primary btn-lg disabled"
tabindex="-1"
role="button" aria-disabled="true"
>
Primary link
</a>
More is on getbootstrap.com
So if you want to make it dynamically, and you don't want to care if it is button or ancor than
in JS script you need something like that
let $btn=$('.myClass');
$btn.attr('disabled', true);
if ($btn[0].tagName == 'A'){
$btn.off();
$btn.addClass('disabled');
$btn.attr('aria-disabled', true);
}
But be carefull
The solution only works on links with classes btn btn-link.
Sometimes bootstrap recommends using card-link class, in this case solution will not work.
Just add a css property:
<style>
a {
pointer-events: none;
}
</style>
Doing so you can disable the anchor tag.
I've ended up with the solution below, which can work with either an attribute, <a href="..." disabled="disabled">, or a class <a href="..." class="disabled">:
CSS Styles:
a[disabled=disabled], a.disabled {
color: gray;
cursor: default;
}
a[disabled=disabled]:hover, a.disabled:hover {
text-decoration: none;
}
Javascript (in jQuery ready):
$("a[disabled], a.disabled").on("click", function(e){
var $this = $(this);
if ($this.is("[disabled=disabled]") || $this.hasClass("disabled"))
e.preventDefault();
})
In Razor (.cshtml) you can do:
#{
var isDisabled = true;
}
Home
You can disable the HTML link as given below:
<style>
.disabled-link {
pointer-events: none;
}
</style>
Google.com
You can use inline JavaScript:
Google.com
you cannot disable a link, if you want that click event should not fire then simply Remove the action from that link.
$(td).find('a').attr('href', '');
For More Info :- Elements that can be Disabled
I would do something like
$('td').find('a').each(function(){
$(this).addClass('disabled-link');
});
$('.disabled-link').on('click', false);
something like this should work. You add a class for links you want to have disabled and then you return false when someone click them. To enable them just remove the class.
To disable link to access another page on touch device:
if (control == false)
document.getElementById('id_link').setAttribute('href', '#');
else
document.getElementById('id_link').setAttribute('href', 'page/link.html');
end if;
I would suggest turning the link into a button and using the 'disabled' attribute. You can see this issue to check how to convert a link to a button: How to create an HTML button that acts like a link
You can use this to disabled the Hyperlink of asp.net or link buttons in html.
$("td > a").attr("disabled", "disabled").on("click", function() {
return false;
});
There is one other possible way, and the one that I like best. Basically it's the same way lightbox disables a whole page, by placing a div and fiddling with z-index. Here is relevant snippets from a project of mine. This works in all browsers!!!!!
Javascript (jQuery):
var windowResizer = function(){
var offset = $('#back').offset();
var buttontop = offset.top;
var buttonleft = offset.left;
$('#backdisabler').css({'top':buttontop,'left':buttonleft,'visibility':'visible'});
offset = $('#next').offset();
buttontop = offset.top;
buttonleft = offset.left;
$('#nextdisabler').css({'top':buttontop,'left':buttonleft,'visibility':'visible'});
}
$(document).ready(function() {
$(window).resize(function() {
setTimeout(function() {
windowResizer();
}, 5); //when the maximize/restore buttons are pressed, we have to wait or it will fire to fast
});
});
and in html
<img src="images/icons/back.png" style="height: 50px; width: 50px" />
<img src="images/icons/next.png" style="height: 50px; width: 50px" />
<img id="backdisabler" src="images/icons/disabled.png" style="visibility: hidden; position: absolute; padding: 5px; height: 62px; width: 62px; z-index: 9000"/>
<img id="nextdisabler" src="images/icons/disabled.png" style="visibility: hidden; position: absolute; padding: 5px; height: 62px; width: 62px; z-index: 9000"/>
So the resizer finds the anchor's (the images are just arrows) locations and places the disabler on top. The disabler's image is a translucent grey square (change the width/height of the disablers in the html to match your link) to show that it is disabled. The floating allows the page to resize dynamically, and the disablers will follow suit in windowResizer(). You can find suitable images through google. I have placed the relevant css inline for simplicity.
then based on some condition,
$('#backdisabler').css({'visibility':'hidden'});
$('#nextdisabler').css({'visibility':'visible'});
I think a lot of these are over thinking. Add a class of whatever you want, like disabled_link. Then make the css have .disabled_link { display: none }
Boom now the user can't see the link so you won't have to worry about them clicking it. If they do something to satisfy the link being clickable, simply remove the class with jQuery: $("a.disabled_link").removeClass("super_disabled"). Boom done!
For some strange reason, the update from Chrome 66 to Chrome 67 broke my web application's WebComponents.
The map at the top is defined via a WebComponent custom element. It should be noted that it isn't rendered through a shadow DOM. It is rendered directly by appending a child <img> to my map component.
Chrome 66's DOM:
<bj-map ...>
<img src="...">
</bj-map>
Chrome 67's DOM:
<bj-map ...></bj-map>
The component's class is Map, extending from HTMLElement. Non-relevant methods have been removed.
class Map extends HTMLElement {
connectedCallback () {
this.render()
}
render () {
const src = this.getMapSource()
this.innerHTML = `
<img src="${src}"></img>
`
}
}
customElements.define('bj-map', Map, { extends: 'div' })
export default Map
Are there any ways that I can try to debug this magical issue?
Remove { extends: 'div' } from customElements.define('bj-map', Map, { extends: 'div' }).
class Map extends HTMLElement is not extending HTMLDivElement so you don't need to specify an extend in define.
Extending native HTML elements has additional details.
My dom repeat displays a list of icons which I can bookmark or unbookmark ,which generating dom-repeat I call a function to find if this icon is bookmarked or not,that will return CSS class
.book-marked {
color: red;
}
.not-book-marked {
color: green;
}
<template is="dom-repeat" items="{{membersList}}">
<iron-icon icon="bookmark" class$="[[_computeBookMark(item.userId)]]" on-tap="_toogleBookMark"></iron-icon>
</template>
Once I get all my list of icon now if user click that icon I need to toogle css class.so I wrote on-tap function
_toogleBookMark:function(e) {
var userData = e.model.item; //gets entire data object of that element
var index = e.model.index; //gets index of that element
},
I can't use ID since its dom-repeat ,Is there any other ways so that I can change CSS of that dom-repeat element in _toogleBookMark() function on clicking? or is it possible to change CSS with index??or using "e" reference in _toogleBookMark(e) function !!
Not sure if I understood correctly - you want to access the element you've tapped?
Just use the event.target property then. It will return the element on which the event happened, in this case, the icon you have tapped.
_toogleBookMark = function(e) {
e.target.classList.toggle("not-book-marked");
}
Check this example.
Mind you:
1) When using Shady DOM, assuming our element is a custom element, target can be a component from the element's template, not the element itself. To prevent that, use Polymer.dom(e).localTarget (read more here).
2) When using a custom element with light DOM children, the above may not be enough, your (local)target will be a light DOM child, not the element you wished for. In that case, use Element.closest(selector) to (optionally) go up the DOM to the element you want. Read more about the method here.
As you just want to swap your class on tap, do it like this:
Add an own attribute, like data-id="1" and the id attribute, but be sure they have the same value:
<template is="dom-repeat" items="{{membersList}}">
<iron-icon icon="bookmark" class$="[[_computeBookMark(item.userId)]]" on-tap="_toogleBookMark" data-id="{{item.userId}}" id="{{item.userId}}"></iron-icon>
</template>
Now, inside your _toggleBookMark function, you can access the current tapped element and swap CSS classes by:
_toogleBookMark:function(e) {
// this gives you your userId from the data-id attribute
var userId = e.path[0].dataId;
// we can access the element now with
var element = this.$$('#' + e.path[0].dataId);
if (element.classList.contains('book-marked')) {
element.classList.remove('book-marked');
element.classList.add('not-book-marked');
} else {
element.classList.add('book-marked');
element.classList.remove('not-book-marked');
}
},
I am using JQueryUI draggable and I would like to be able to add styling to the draggable element while it is being dragged. I have tried variations on this code:
$(".ui-widget-content").draggable({
drag: function(event, ui) {
$(this).css("width", "50px");
});
However, my attempts have failed and I believe it it because I don't know how to get the draggable element from the ui object. What am I missing?
No need for extra JavaScript. Just use this CSS selector:
.ui-draggable-dragging {
/*
This class is applied to the element while it is being dragged.
This is done automatically by jQueryUI.
*/
width: 50px;
}
Read the docs here: http://jqueryui.com/demos/draggable/#overview-main