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 ^_^
Related
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
I have an app that has several different types of form elements which all post data to the server with jQuery AJAX.
What I want to do is:
Show a loader during AJAX transmission
Prevent the user from submitting twice+ (clicking a lot)
This is easy to do on a one off basis for every type of form on the site (comments, file upload, etc). But I'm curious to learn if that is a more global way to handle this?
Something that's smart enough to say:
If a form is submitting to the server and waiting for a response, ignore all submits
Show a DISABLED class on the submitted / clicked item
Show a loading class on the class="spinner" which is closest to the submit item clicked
What do you think? Good idea? Done before?
Take a look at the jQuery Global Ajax Event Handlers.
In a nutshell, you can set events which occur on each and every AJAX request, hence the name Global Event Handlers. There are a few different events, I'll use ajaxStart() and ajaxComplete() in my code sample below.
The idea is that we show the loading, disable the form & button on the ajaxStart() event, then reenable the form and hide the loading element inside the ajaxComplete() event.
var $form = $("form");
$form.ajaxStart(function() {
// show loading
$("#loading", this).show();
// Add class of disabled to form element
$(this).addClass("disabled");
// Disable button
$("input[type=submit]", this).attr("disabled", true);
});
And the AJAX complete event
$form.ajaxComplete(function() {
// hide loading
$("#loading", this).hide();
// Remove disabled class
$(this).removeClass("disabled");
// Re-enable button
$("input[type=submit]", this).removeAttr("disabled");
});
You might need to attach to the ajaxError event as well in case an AJAX call fails since you might need to clean up some of the elements. Test it out and see what happens on a failed AJAX request.
P.S. If you're calling $.ajax or similar ($.getJSON), you can still set these events via $.ajaxStart and $.ajaxComplete since the AJAX isn't attached to any element. You'll need to rearrange the code a little though since you won't have access to $(this).
I believe you have to do 2 for sure and 3 to improve usability of your app. It is better to keep backend dumb but if you have a security issue you should handle that too.
I've been working on Chrome Extension for a website for the past couple of days. It's coming along really nicely but I've encountered a problem that you might be able to help with.
Here's an outline of what the extension does (this functionality is complete):
A user can enter their username and password into the extensions popup - and verify their user account for the particular website
When a user browses http://twitter.com a content script is dynamically included that manipulates the DOM to include an extra button next to each tweet displayed.
When a user clicks this button they are presented with a dialog box
I've made a lot of progress but here is my problem:
When a user visits Twitter the content script is activated and all tweets on the page get my new button - but if the user then clicks 'More...' and dynamically loads the next 20 tweets... these new additions to the page DOM do not get affected by the content script (because it is already loaded).
I could add an event listener to the 'More...' button so it then triggers the original content script again (and adds the new button) but i would have to predict the length of twitter's ajax request response.
I can't tap into their Ajax request that pulls in more tweets and call my addCurateButton() function once the request is complete.
What do you think is the best solution? (if there is one)
What you want to do is to re-execute your content-script every time the DOM is changed. Luckily there is an event for that. Have a look at the mutation event called DOMNodeInserted.
Rewrite your content script so that it attaches an event listener to the body of the DOM for the DOMNodeInserted event. See the example below:
var isActive = false;
/* Your function that injects your buttons */
var inject = function() {
if (isActive) {
console.log('INFO: Injection already active');
return;
}
try {
isActive = true;
//inject your buttons here
//for the sake of the example I just put an alert here.
alert("Hello. The DOM just changed.");
} catch(e) {
console.error("ERROR: " + e.toString());
} finally {
isActive = false;
}
};
document.body.addEventListener("DOMNodeInserted", inject, false);
The last line will add the event listener. When a page loads the event is triggered quite often so you should define a boolean (e.g. var isActive), that you initialize to false. Whenever the inject function is run check whether isActive == true and then abort the injection to not execute it too often at the same time.
Interacting with Ajax is probably the hardest thing to coax a content script to do, but I think you’re on the right track. There are a couple different approaches I’ve taken to solving this problem. In your case, though, I think a combination of the two approaches (which I’ll explain last) would be best.
Attach event listeners to the DOM to detect relevant changes. This solution is what you’ve suggested and introduces the race condition.
Continuously inspect the DOM for changes from inside a loop (preferably one executed with setInterval). This solution would be effective, but relatively inefficient.
The best-of-both-worlds approach would be to initiate the inspection loop only after the more button is pressed. This solution would both avoid the timing issue and be efficient.
You can attach an event-handler on the button, or link that is used for fetching more results. Then attach a function to it such that whenever the button is clicked, your extension removes all the buttons from DOM and starts over inserting them, or check weather your button exists in that particular class of DOM element or not and attach a button if it doesn't.
Working on a Wicket application that adds markup to the DOM after onLoad via Wicket's built-in AJAX for an auto-complete widget. We have an IE6 glitch that means I need to reposition the markup coming in, and I am trying to avoid tampering with the Wicket javascript... blah blah blah... here's what I'm trying to do:
New markup arrives in the DOM (I
don't have access to a callback)
Somehow I know this, so I fire my
code.
I tried this, hoping the new tags would trigger onLoad events:
$("selectorForNewMarkup").live("onLoad", function(){ //using jQuery 1.4.1
//my code
});
...but have become educated that onLoad only fires on the initial page load. Is there another event fired when elements are added to the DOM? Or another way to sense changes to the DOM?
Everything I've bumped into on similar issues with new markup additions, they have access to the callback function on .load() or similar, or they have a real javascript event to work with and live() works perfectly.
Is this a pipe dream?
.live() doesn't work like this, it's a common misconception. .live() creates an event handler at the DOM root and waits for events to bubble up to it. If the selector matches the event target, .live() will fire the bound event.
It doesn't look for new objects and bind events to them in any way, rather it just listens for a bubble, and doesn't care when that object was added to the DOM.
You need to fire whatever code is needed to run manually when your load operation completes.
What will this is the livequery plug-in, look specifically at the livequery( matchedFn ) call.
You can do something like this:
$('#myID').livequery(function() { $(this).offset()...stuff });
i guess this is what you are looking for http://ananthakumaran.github.com/2010/02/19/wicket-post-ajax-handling.html
After I load a page through a WebBrowser, and I click a link that fires an AJAX script, I need to detect when the AJAX java script finishes loading HTML changes into a div. Since no DocumentCompleted event is fired when the AJAX script is run, I don't know when it finish running. Is there a way I can attach an event to be raised after I know 100% that the javascript finished changing the div?
The project is in C#.
Thanks
I did something similar recently (using jQuery):
$('#mydiv').change(function(){
// do stuff
}
);
Granted, I also use jQuery to set the HTML of that div. I suppose one non-jQuery approach for you could be to set HTML through your own function, which in turn can fire an onchange event.
#New in town: From my experience that is not correct. I use this on multiple DIVs that never get focus in the first place, and it works well and consistently. The normal behavior is as you describe, and normally only applies to the INPUT and SELECT elements, but this is not the case with jQuery.
There is no event. You must patch the JavaScript callback that the browser runs when the reply for the AJAX request comes in. This will contains code like "div.innerHTML = ...". Just put your code below that.