I keep getting puzzled, can't find a contextmenu that will work for me. Maybe someone can help?
Here's to what I need contextMenu to be added to:
<ul id="list_{id}" class="list">
<li id="Item_{id}"><a ondblclick=""><span>{title}</span></a></li>
</ul>
This is dynamic list, so it will add many more of them on the page and differ them by giving different ID's. So I need a contextMenu which will be added to every list but for each list an unique contextMenu. Basically different instances of contextMenu in every list, by adding dynamic {id} tag to the ID of contextMenu or something like that.
Thanks
It's kind of hard to tell what you're asking, but if you want to hook into the "context menu" event of a browser, you hook the contextmenu event and then do whatever you're going to do (which could include creating a div, for instance, with options on it — e.g., your own context menu). You can either do that on the lists themselves, individually, via getElementById as you indicated in your question, or you can do it by hooking the event on some container that holds all of the lists, and then figuring out when the event is triggered which list it was triggered on ("event delegation").
See the end of this answer for the event delegation approach. But assuming you have a way of knowing the actual IDs used and you want to hook each list specifically for some reason:
HTML:
<ul id='list_1'>
<li>List 1 item 1</li>
<li>List 1 item 2</li>
</ul>
<ul id='list_2'>
<li>List 2 item 1</li>
<li>List 2 item 2</li>
</ul>
JavaScript:
hookEvent(document.getElementById('list_1'), 'contextmenu', function(event) {
event = event || window.event;
if (event.preventDefault) {
event.preventDefault();
}
display("List 1 context menu");
return false;
});
hookEvent(document.getElementById('list_2'), 'contextmenu', function(event) {
event = event || window.event;
if (event.preventDefault) {
event.preventDefault();
}
display("List 2 context menu");
return false;
});
function hookEvent(element, event, handler) {
if (element.addEventListener) {
element.addEventListener( event, handler, false);
}
else if (element.attachEvent) {
element.attachEvent('on' + event, handler);
}
else {
element['on' + event] = handler;
}
}
Live example
Note that only some (most) browsers let you cancel the default context menu.
Update: Re your "but what if the ID is bindable?" question below: I'm afraid I don't know what you mean by "bindable" — none of the tags on your question indicates a specific templating technology. You haven't even mentioned whether the templating is happening server-side or client-side, which makes it hard to help. But basically, by the time the JavaScript is running, there will be real IDs on real elements in the document. You'll have to know what those IDs are in order to use getElementById.
Server-side templating:
If those IDs are going to be completely dynamic and the template is being handled on the server, you can include a small bit of script that passes those IDs on to JavaScript. For instance, near the top of your document you might have:
<script type='text/javascript'>
var mySpecialListIDs = [];
</script>
...and then update your template to add a small script tag each time it's expanded:
<ul id="list_{id}" class="list">
<li id="Item_{id}"><a ondblclick=""><span>{title}</span></a></li>
</ul>
<script type='text/javascript'>
mySpecialListIDs.push("{id}");
</script>
Then your client-side code can loop through mySpecialLitIDs and use each ID when hooking up the handler.
Client-side templating:
If the templating is being done client-side, this gets a bit simpler: Just set up your mySpecialListIDs list at some convenient place in your client-side script, and the append to it each time you call the templating engine.
Event Delegation: Whether you're doing server- or client-side templating, if you're going to have dynamic lists like this, sometimes event delegation is the best way to handle it. The contextmenu event (like most, but not all, events) bubbles up the DOM. So if you hook it on an ancestor element (something that contains all of your lists, like the document body itself or some such), you can then see which actual list was clicked by examining the event object. Like this:
HTML:
<div id='list_container'>
<ul id='list_1'>
<li>List 1 item 1</li>
<li>List 1 item 2</li>
</ul>
<ul id='list_2'>
<li>List 2 item 1</li>
<li>List 2 item 2</li>
</ul>
</div>
JavaScript (using the hookEvent function from above):
// Hook up the contextmenu event on the container, not
// on each list:
hookEvent(document.getElementById('list_container'),
'contextmenu',
handleListContextMenu);
// Our handler function
function handleListContextMenu(event) {
var target;
// Handle IE-vs-the-world difference
event = event || window.event;
// Find out what the actual target element clicked was
target = event.target || event.srcElement;
// See if it or an ancestor of it is one of our lists
while (target &&
(target.tagName !== "UL" || !target.id || target.id.substring(0, 5) !== "list_")) {
target = target.parentNode;
}
// Did we find a list?
if (target) {
// Yes, handle this.
if (event.preventDefault) {
event.preventDefault();
}
display("List '" + target.id + "' context menu");
return false;
}
}
Live example
Related
I have made a basic mobile navigation dropdown menu that makes use of nested tags to open the second (and third) level of the navigation. However because the elements are nested in anchor tags, they also trigger the default anchor events. Is there any way to prevent the anchors default event when clicking on a child element of said anchor ?
HTML
<ul class="main-menu">
<li>
<a href="some-link.html">Some Link
<span class="target"></span>
</a>
<ul class="submenu">
<li>Some Link</li>
<li>Some Link</li>
<li>Some Link</li>
</ul>
</li>
</ul>
Example Javascript
$('span.target').on('click', function(event) {
$(event.target).parent().preventDefault();
// Do somthing
});
You could stop the propagation of the event, and cancel it's default behavior. See this:
$('span.target').on('click', function(event) {
event.stopPropagation();
event.preventDefault();
// the rest of your code here...
});
As mentioned in the comments, I add those 2 lines as part of my 'automatic' workflow, in case I'm binding to an anchor tag (a) and prevent the default behavior of navigating away from the page (that's preventDefault()), and stopPropagation to avoid the parent elements' bound events from being triggered.
You can try this code. When you click on the child on anchor it prevents default behaviour of the parent anchor element. I use core javascript here:
var menuAnchor = document.querySelectorAll('.main-menu a');
for(var i = 0, len = menuAnchor.length; i < len; i++){
menuAnchor[i].addEventListener('click', function(event){
if(event.target != this) event.preventDefault();
});
}
What approach would you recommend to control the whole app with keyboard only? I found Spotlight lib, but it depends on enyojs which seems to have its own component model and overall enyojs seems to be an overkill.
So far I'm listening on keydown events in app.component.ts:
#HostListener('window:keydown', ['$event']) onKeydown(event: any) {
event.preventDefault();
this.mainKeydownHandler.handle(event.keyCode);
}
Each component which want to handle keydown events registers to MainKeydownHandler's handlers and when keydown event occures MainKeydownHandler delegates an event to the registered handler. The appropriate handler is determined by document.activeElement's class (I did not find more "angular2-like" way to get currently focused elem) in MainKeydownHandler's handle method. So now I have to add appropriate class name to a group of elements I want to be able to focus.
Furthermore, component's handler gets all selectable elements with:
#ViewChildren('selectable') elements: QueryList<ElementRef>;
so I need to add #selectable and class with ID of handler to each element I want to focus. Component's handler then receives keyCode and determines which element to select next, or return to previouslly selected elem from another component and so on.
This approach seems awkward, involves quite a lot of code when new component want to handle keydown events and there are situations when a component completely loses focus: when I delete an item from some list and then this component is rerendered (some service or MainKeydownHandler could remember, but this could lead to quite a lot of elements to remember along the way navigating user through components).
Is there a better, simpler, more generic and more declarative way to control entire angular2 app with keyboard-only (keydown/keyup events)?
Alternatively, is it reasonable to use Spotlight (with enyojs dep.) with angular2 for this use-case? And can you provide working plunker with angular2+spotlight. I could not get these two to work together.
If you want to enable basic keyboard navigation, you can do it with tabindex which is a standard way of doing it. See the specification
document.getElementById('mylist').focus();
:focus{
border: 1px solid red;
}
Press TAB to navigate.
<ul id="mylist" tabindex="-1">
<li tabindex="1"> One </li>
<li tabindex="2"> Two </li>
<li tabindex="4"> Four </li>
<li tabindex="3"> Three </li>
</ul>
If you want to do it with arrow keys, you will have to listen to keydown event on the document and manually focus() the elements using javascript. It will be easier to navigate back and forth, not that direct to find the element that is above and below current element in layout. You will have to compare x,y coordinates or offsets.
document.getElementById('mylist').focus();
window.onkeydown = function(e) {
var curr = document.activeElement;
var treeWalker = document.createTreeWalker(
document.body,
NodeFilter.SHOW_ELEMENT,
{ acceptNode: function(node) { return (node.tabIndex === -1)?NodeFilter.FILTER_SKIP: NodeFilter.FILTER_ACCEPT} },
false
);
treeWalker.currentNode = curr;
if (e.keyCode == 39) {
treeWalker.nextNode().focus();
}
if (e.keyCode == 37) {
treeWalker.previousNode().focus();
}
};
:focus {
border: 1px solid red;
}
Press Right/Left arrow keys to navigate
<ul id="mylist" tabindex="-1">
<li tabindex="1">One</li>
<li tabindex="2">Two</li>
<li tabindex="4">Four</li>
<li tabindex="3">Three</li>
<li>Not selectable</li>
<li tabindex="5">Five</li>
</ul>
You can take a look at https://github.com/luke-chang/js-spatial-navigation It's a generic spatial navigation library. It should be able to be integrated easily with Angular.
You may also want to check out this related SO: Navigate the UI using only keyboard
And this Angular TV app which purports to have spatial navigation: https://github.com/ahmednuaman/angular-tv-app
Hey so here is the code demo I made
<!DOCTYPE html>
<html>
<head>
<script src="https://code.jquery.com/jquery-1.11.3.min.js"></script>
</head>
<body>
<ul contenteditable class="outerList">
<li class="innerElement">Hello</li>
<li class="innerElement">World</li>
<li class="innerElement">Hello World</li>
</ul>
<script>
$(".outerList").keydown(function () {
console.log("I am the outer ul");
});
$(".innerElement").keydown(function() {
console.log("I am an inner element");
});
</script>
</body>
</html>
and here is the jsFiddle to run it
http://jsfiddle.net/scrbovyr/
Basically I have a content editable UL and I want to catch the enter key and pass in my own custom function. But I need to know which LI element the keydown event was thrown on. And as shown in the demo, I can only seem to tie a keydown event listener (or any event listener for that matter) to the outer UL element. Is there a way to attach the keydown event to each LI? Or is there at least a way to attach it to the UL but still tell which child it came from?
Thanks in advance, let me know if any additional information would help!
You will have to add contenteditable to your li elements in order to achieve that. You are setting contenteditable to your ul element, thus, the event will be binded to that element, you may edit the li elements, but they do not have contenteditable set, so the keyboard events won't be triggered for those elements.
<ul class="outerList">
<li contenteditable class="innerElement">Hello</li>
<li contenteditable class="innerElement">World</li>
<li contenteditable class="innerElement">Hello World</li>
</ul>
And then:
$(".innerElement").keydown(function() {
console.log("I am an inner element");
});
You may check the node at the current selection
If you don't want to make each li a contenteditable element, you may get the element at the current selection or caret position and perform a check against it.
The embedded example shows how you would achieve this using the Web API Interface for contenteditable selections. (I tested this in Chrome, but it may need additional logic to achieve cross-browser compatibility).
It is also worth noting that you can bind some event listeners to the children of a contenteditable element. For example, the click event may be bound to the li elements as you can see in the embedded example.
$(document).ready(function() {
function getCurrentNode() {
var node = window.getSelection().getRangeAt(0).commonAncestorContainer;
return node.nodeType === 1 ? node : node.parentNode;
}
$('.outerList').on('click keyup', function (e) {
var $target = $(getCurrentNode()),
$closest = $target.closest('b');
console.log(e.type);
console.log('I am the outer ul');
console.log($target);
// Optional. Filter by clostest selector.
if ($closest.length) {
console.log('Target matches selector', $closest);
}
});
$('.innerElement').on('click', function (e) {
console.log(e.type);
console.log('I am an inner element');
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul contenteditable class="outerList">
<li class="innerElement">Hello</li>
<li class="innerElement"><i>Hello</i></li>
<li class="innerElement"><b><i>Hello</i></b></li>
<li class="innerElement"><b>Hello</b></li>
<li class="innerElement">Hello</li>
<li class="innerElement">Hello</li>
</ul>
Im trying to create a false hover event for my site using jQuery...
I have created the following only all the child elements in my list now return false also as opposed to linking to the correct page...
if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i)) || (navigator.userAgent.match(/iPad/i))) {
$("ul.sf-menu li.i").click(function(e) {
e.preventDefault();
});
}
Has anybody an idea on an alternative method that could work?
HTML
<ul class="sf-menu"> <li>Home<li class="i">Weddings
<ul>
<li>Peel Suite</li>
<li>The Hall</li>
<li>The Grounds</li>
<li>Food & Drink</li>
<li>Pricing</li>
</ul>
</li>
well. without HTML its kind of hard to tell. But you are stopping the default behavior of the browser when the user clicks on the li (and therefor also its children, which I suppose is an anchor/link).
you could check if its a link or an anchor on click and handle it differently;
$("ul.sf-menu li.i").click(function(e) {
if (e.target.nodeName!=="A"){
e.preventDefault();
//do your hover code
}
else{
//do nothing, because the user wants the link to load
}
});
change youre selector so it only matches the first level of listpoints, also i dont see a class i so you might need to drop that from the selector aswell.
$("ul.sf-menu > li")
I have a hierarchy of tags within my HTML which all contain onclick event handlers. The onclick is pushed onto the event stack from the leaf back through the root of the hierarchy. I only want to respond to the leaf onclick event. Can I flush the event stack rather than using a flag?
For instance:
<ul>
<li onclick="nada('1');">1</li>
<li onclick="nada('2');">2
<ul>
<li onclick="nada('2.1');">2.1</li>
<li onclick="nada('2.2');">2.2</li>
<li onclick="nada('2.3');">2.3</li>
</ul>
</li>
<li onclick="nada('4');">4</li>
<li onclick="nada('5');">5</li>
</ul>
Clicking on 2.2 using this function...
function nada(which)
{
alert(which);
}
...will result in two alerts for '2.2' and '2'.
What could I add to the nada function to eliminate the alert for '2'?
To stop the event bubbling up to parent elements you have to tell the event object about it. In IE, you set event.cancelBubble= true. In other browsers, you call event.stopPropagation().
You probably also want to turn off the default link-following action so that the browser doesn't keep jumping up to the top trying to follow the non-existing anchor links like #1. In IE, you set event.returnValue= false. In other browsers, you call event.preventDefault().
The event object is accessible as window.event on IE. On other browsers, it is passed into the event handler function. A way to pass the event into a function that works on both is:
<li onclick="nada('2.1', event);">2.1</li>
function nada(n, event) {
alert(n);
if ('stopPropagation' in event) {
event.stopPropagation();
event.preventDefault();
} else {
event.cancelBubble= true;
event.returnValue= false;
}
}
However it would probably be better all round to put the onclick event on the a element which it usually belongs. This helps for accessibility, as the a element will be focusable and keyboard-operable. And it means you don't have to worry about parents' click handlers being called.
(You can style the a to look like a plain block, if you want.)
You can then also kick out the redundant onclick links with a bit of unobtrusive scripting:
<ul id="nadalist">
<li>1</li>
<li>2
<ul>
<li>2.1</li>
<li>2.2</li>
<li>2.3</li>
</ul>
</li>
<li>4</li>
<li>5</li>
</ul>
<script type="text/javascript">
var links= document.getElementById('nadalist').getElementsByTagName('a');
for (var i= links.length; i-->0;) {
links[i].onclick= function() {
alert(this.hash.substring(1));
return false;
}
}
</script>