I wonder if anybody else is having this issue. I'm using Firefox 4 and I'm debugging a function from an onclick event using Firebug. Now, to be sure, I checked the stack and it clearly shows that an onclick event was fired. However, when I type "event" (without quotse) in the watch pane, it says it's undefined. Why? Now it recognizes "Event", but not "event". Is anybody else having this issue?
Thank you.
When debugging inside of your event function, add a watch for arguments[0]; this is the event object you are looking for.
Modern, standards-compliant browsers don't use a window.event object in the manner that some versions of Internet Explorer do.
In these browsers, the event is passed to the event handler as an argument. So if you do something like the following...
function foo(bar) {
// do stuff
}
document.getElementById("myElement").onclick = foo;
...then when #myElement is clicked, the browser will execute foo(bar), where bar is the event object. If you need to see the event object's details, you would have to set a breakpoint inside of foo and add a watch for bar or for arguments[0].
Related
For HTML inputs (notably, textarea), I can send a fake jQuery event to my input while testing in Jasmine and observe behavior that would occur in a browser if that same event were initiated by a user.
For example,
var $input = $('textarea');
var e = new jQuery.Event('keydown', { which: 13 });
$input.trigger(e);
This code would find my input and send a fake enter keydown during the test, and event handlers update the page in Jasmine. Then I can check values of elements on the page, or assess whether my spies have been called.
Unfortunately, this doesn't seem to work with Quill. I have verified that the input exists, that the input is focused, that my onEnter handler exists, etc. Yet, I have been struggling to figure out how to use a simulated/automated event to test this library.
Any help is greatly appreciated ^_^
I want to get the list of all events for any particular component dynamically. For example : If I take a Textfield , how can I get all possible events that are mentioned in ExtJs API Doc. so that user can choose and assign the event for any component.
component.events
Contains the list you need. You could have found out by yourself reading the source of addEvents method, which is linked from any event you wanted to find in a list.
For those still wanting an answer to this, https://coderwall.com/p/jnqupq/easily-capture-all-events-on-a-component-in-extjs has provided a nice means of doing so.
When debugging an ExtJS application, you'll often find it useful to listen to all events fired by a specific component. There is actually a handy built-in static method to do this called Ext.util.Observable.capture().
Here's a handy snippet that simply logs the event name and all arguments:
Ext.util.Observable.capture(myObj, function(evname) {console.log(evname, arguments);})
Even better, if you're currently inspecting your component's main element in your browser's developer tools, you can do this:
Ext.util.Observable.capture(Ext.getCmp($0.id), function(evname) {console.log(evname, arguments);})
Where $0 is the currently selected element. Should work fine in Chrome, Firefox, Opera, Safari.
If you don't want those logs to pollute your console anymore, simply call releaseCapture on your object:
Ext.util.Observable.releaseCapture(myObj);
This removes all captures on a given object so you don't have to reference your listener explicitly (which was likely an anonymous function :)).
Bonus tip: also be sure to check out the observe method which does something similar but allows you to listen to all events fired by all instances of a given class.
$('#my-view').on('show', showHandler)
Doesn't work. Using data-show is not an option either because the code that sets/unsets the event is within class that is instantiated later. Also creating the view programatically and passing in the event handler doesn't work because I need to set the event on/off at different times.
Is this not possible with kendoUI? If not, why? This seems like such an incredibly obvious feature to relay those events to the element themselves similar to what is possible with jquery ui widgets.
This works:
var view = $('#my-view');
var widget = kendo.widgetInstance(view);
widget.bind('show', showHandler);
Better answer, just delegate the events yourself so the code in the question actually works:
<div data-role="view" ... data-show="onShow">...</div>
and
function onShow () {
this.element.trigger('show');
}
Now the it works :). The problem I still has was that 'show' isn't triggered when a view is first shown if it is the first view shown. Er, so yeah I had to add some extra code for that too like this:
if ($('#my-view').is(':visible')) {
$('#my-view').trigger('show');
}
Lame but it works.
I was under the impression that jQuery's on event handler was meant to be able to 'listen' for dynamically created elements AND that it was supposed to replace the behavior of live. However, what I have experienced is that using on is not capturing the click event whereas using live is succeeding!
The tricky aspect of my situation is that I am not only dynamically creating content but I'm doing it via an AJAX .get() call, and inserting the resultant HTML into a modal .dialog() jQueryUI popup.
Here is a simplified version of what I was trying to accomplish (wrapped in $(document).ready(...) ):
$.get("getUserDataAjax.php", queryString, function(formToDisplay) {
$("#dialog").dialog({
autoOpen: true,
modal: true,
buttons...
}).html(formToDisplay);
});
$(".classThatExistsInFormToDisplay").on("click", function() {
alert("This doesn't get called");
});
From the documentation for on I found this which which was how I was approaching writing my on event:
$("p").on("click", function(){
alert( $(this).text() );
});
However, for some reason, live will work as I expect -- whereas on is failing me.
This isn't a question for "how can I make it work" because I have found that on will succeed (capture clicks) if I declare it inside the function(formToDisplay) callback.
My question is: what is wrong with on that it isn't finding my dynamically created elements within a modal popup? My jQuery instance is jquery-1.7.2. jQueryUI is 1.8.21.
Here are two jsFiddles that approximate the issue. Click the word "Test" in both instances to see the different behavior. The only difference in code is replacing on for live.
Where the click is captured by live.
Where the click is NOT captured by on (click 'Test - click me' to see nothing happen).
I realize I may just be using on inappropriately or asking it to do something that was not intended but I want to know why it is not working (but if you have something terribly clever, feel free to share). Thanks for your wisdom!
Update / Answer / Solution:
According to user 'undefined', the difference is that on is not delegated all the way from the top of the document object whereas live does/is.
As Claudio mentions, there are portions of the on documentation that reference dynamically created elements and that what you include in the $("") part of the query needs to exist at runtime.
Here is my new solution: Capture click events on my modal dialog, which, although it does not have any content when the event is created at runtime, will be able to find my content and element with special class that gets generated later.
$("#dialog").on("click", ".classThatExistsInFormToDisplay", function() {
... //(success! Event captured)
});
Thanks so much!
live delegates the event from document object, but on doesn't, if you want to delegate the event using on method, you should delegate the event from one of static parents of the element or document object:
$(document).on("click", ".clickHandle", function() {
alert("Content clicked");
});
The problem is that the element to which you attach the event has to exist.
You have to use on like this to capture clicks on p tags created dynamically
$("#existingContainerId").on("click", "p", function(){
alert( $(this).text() );
});
if you have no relevant existing container to use, you could use $("body") or $(document)
If selector is omitted or is null, the event handler is referred to as direct or directly-bound. The handler is called every time an event occurs on the selected elements, whether it occurs directly on the element or bubbles from a descendant (inner) element.
When a selector is provided, the event handler is referred to as delegated. The handler is not called when the event occurs directly on the bound element, but only for descendants (inner elements) that match the selector. jQuery bubbles the event from the event target up to the element where the handler is attached (i.e., innermost to outermost element) and runs the handler for any elements along that path matching the selector.
Event handlers are bound only to the currently selected elements; they must exist on the page at the time your code makes the call to .on(). To ensure the elements are present and can be selected, perform event binding inside a document ready handler for elements that are in the HTML markup on the page. If new HTML is being injected into the page, select the elements and attach event handlers after the new HTML is placed into the page. Or, use delegated events to attach an event handler, as described next
Take a look to section Direct and delegated events here for more details
This code:
function attachDateNavEventHandler() {
$('.ui-datepicker-title option').each(function () {
$(this).mouseup(setFlag);
});
attaches the event fine in FF but not in IE 8 or Chrome. I'm working with the jQuery datepicker and want to set a flag if the user navigates with the month or year drop-downs. I can't seem to attach to the onchange event of the selects. I think there must be an internal block on those events. I also had trouble using a simple click
Any suggestions mooooooost welcome :).
Try:
$(this).on('mouseup', setFlag);
Though this is basically the same thing you have.
I have a feeling that the options themselves may have the funny business. Options can't do everything that a typical HTML element can, but I'm not certain of the limitations on what browsers.
What about setting an on change on the whole select itself instead of trying to listen for mouseup events of each individual option.
$('.ui-datepicker-title').change(