I have a problem which I don't know is related to the meteor implementation of events or to Javascript events in general.
I have a textbox attached to a "change" event.
Next to it, I have a button attached to a "click" event.
When I do a change in the textbox and click the button, the click event does not fire (only the change event does). So I have to click the button two times for the click event to fire.
In Firefox, it works if I attach a mousedown event instead of the click event to the button. In Chrome it doesn't work either ways.
Minimal code reproducing the problem:
JAVASCRIPT: testevent.js
if (Meteor.isClient) {
Session.set("something", "something");
Template.hello.foo = function() {
return Session.get("foo");
};
Template.hello.something = function() {
return Session.get("something");
}
Template.hello.events({
'click .buttonid' : function () {
console.log("click !");
},
'change .textid' : function (e,t) {
console.log("change !");
var bar = e.target.value;
Session.set("foo",bar);
}
});
}
if (Meteor.isServer) {
Meteor.startup(function () {
// code to run on server at startup
});
}
HTML: testevent.html
<head>
<title>testevent</title>
</head>
<body>
{{> hello}}
</body>
<template name="hello">
<input type="text" class="textid" value="{{foo}}"/>
<input type="button" class="buttonid" value="{{something}}" />
</template>
When I replace class with id the click event fire, but when I have multiple fields with the same id the events work only on one field.
The issue has to do with the hello.foo:
Template.hello.foo = function() {
return Session.get("foo");
};
and the fact that the value of foo is used to reactively populate the text input. If you remove the hello.foo function everything works as expected. When the user clicks the button, the change event fires which sets the "foo" session variable which in turn causes the template to re-render. I think the rendering process clears the remaining event queue, so the click handler never fires.
There are a couple of ways you can fix this. An easy (but crude) way is just to delay setting the session variable in the change event handler. For example:
Meteor.setTimeout(function(){Session.set("foo", bar);}, 100);
Obviously you would need to choose an appropriate delay and that may be browser/data dependent. Alternatively, you can just put the text input in its own template. For example:
<template name="hello">
{{> helloText}}
<input type="button" class="buttonid" value="{{something}}" />
</template>
<template name="helloText">
<input type="text" class="textid" value="{{foo}}"/>
</template>
After binding the events properly to this new template, you will find that helloText will be rendered separately from hello and thus your events will be preserved.
Related
I have an input field and a button. It is necessary that when the button is clicked the input field gets focus.
I need the behaviour to be slightly different depending on whether the input field was focused manually by the user or if it was focused due the button being clicked.
It seems this would be relatively simple, but I couldn't come up with a solution so far. Any ideas very welcome.
$("button").click(function() {
target_input = $("input");
target_input.focus();
});
$("input").focus(function() {
// if focus done manually by user
// do something
// if focus done via button
// do something else
});
Here is a solution that uses no extra variables, instead it checks the event.
$("button").click(function() {
target_input = $("input");
target_input.focus();
});
$("input").focus(function(e) {
// if focus done manually by user
// do something
// if focus done via button
// do something else
if(e.originalEvent.relatedTarget){
// only from button events
}
// here is from all events
});
this e.originalEvent.relatedTarget will return null if we didn't use the button to originate the focus.
remember to add e to the function.
You should be able to use Event.isTrusted for this:
The isTrusted read-only property of the Event interface is a boolean
that is true when the event was generated by a user action, and false
when the event was created or modified by a script or dispatched via
dispatchEvent.
$("input").focus(function(e) {
if(e.isTrusted) {...} else {...}
});
As noted in the comments, neither IE nor Safari like this.
This works without global variables and it is cross-browser working solution:
$('button').click(function () {
$(this).prev('input').focus()
})
$('input').click(function (e) { // yes, listen to click instead
// original event exists only if input was clicked directly
if (e.originalEvent) {
console.log('manually triggered')
}
})
<div style="background-color: yellow;">
<input type="text">
<button>Focus input</button>
<br>
<input type="text">
<button>Focus input</button>
</div>
<script src="https://unpkg.com/jquery"></script>
I have a dead simple search form:
<div>
<input id="searchArea" type="text" value="" placeholder="Enter your search terms">
<button id="searchButton">Search</button>
</div>
and a snippet of Javascript controlling it:
function searchFunction() {
console.log("This is a POST request being send to the server");
}
$("#searchButton").on("click", function(e) {
e.preventDefault();
searchFunction();
})
$("#searchArea").on("change", function(e) {
e.preventDefault();
searchFunction();
});
The problem is that click and change overlap in functionality and so I get the following:
When I type something in the text box and then click elsewhere in the screen, searchFunction is fired properly but if "elsewhere" becomes the search button, then searchFunction double fires.
My question is this: Once inside the click handler, is there any way to cancel the change handler from firing as well which would otherwise cause searchFunction to double fire?
Mind that searchArea and searchButton don't have a parent-child relationship which means conventional methods like preventDefault and stopPropagation won't work.
You can see it in action in this fiddle.
$(":input").on("change", function(e) {
console.log("change triggered");
$("#section").html("<button id='order'>Order</button>");
registerButtons();
});
function registerButtons() {
$("#order").on("click", function(e) {
console.log("click triggered");
alert("Hello World");
});
$("#order").on("mousedown mouseup", function(e) {
console.log(e.type + " triggered");
});
}
registerButtons();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" value="123"/>
<div id="section">
<button id="order">Order</button>
</div>
I have a web page with a button and some input fields.
On the button an click event is registered
On the input fields an change event is registered
The onChange will trigger an AJAX server call, and the result will replace parts of the web page - including the button. After AJAX result is processed, all listener are registered again.
Now the problem. A user changes the value of an input field, and clicks directly the button - but to slow (lets assume the user needs 500ms for the click), so the onChange event is fired and the page is "updated/replaced". Now the "old" button fires an onMouseDown and the "new" button fires an onMouseUp event - but no onClick.
My current workaround is, to register the two mouseDown/mouseUp events, get the timestamp of the mouse down, and if the mouse up comes in 2 seconds, do what should be done by the onClick.
It is no option to remove the button part from the AJAX response - in worst case the button could be removed and replaced by an user info.
My hope is, that there is a better solution... any ideas?
You can take advantage of the event delegation and set your listener on the container instead of the button.
You are adding a click listener to your old button and your adding a new button to the dom. So the click won't work.
The button wasn't working because for some reason it can't focus when you hover over it. So I added a getFocus method and now it should work.
$("input").on("change", function(e) {
console.log("change triggered");
$("#section").html("<button id='order'>Order</button>");
});
function registerButtons() {
$('#section').on("mouseup", '#order', function(e) {
alert('Clicked!');
});
}
registerButtons();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" value="123"/>
<div id="section">
<button id="order">Order</button>
</div>
I just found out that jQuery provides a sweet API that can be used for event delegation. This way we don't have to manually check for event target. Check it out http://api.jquery.com/on/
$("input").on("change", function(e) {
console.log("change triggered");
$("#section").html("<button id='order'>Order</button>");
});
function registerButtons() {
$("#section").on("click", '#order', function(e) {
console.log("click triggered");
alert("Hello World");
});
$("#section").on('mouseover','#order', function(e){
$(this).focus();
});
}
registerButtons();
I've been working on trying to trigger an onchange listener with java script in Mozilla Firefox. I've found a lot on Stack Overflow posted about this, but nothing seems to be working for my unique case.
I've created this HTML with a onchange listener from an onchange event using this helpful post (JavaScript OnChange Listener position in HTML markup). Here's my code:
<HTML>
<head>
<script type="text/javascript">
window.onload= function () {
if(window.addEventListener) {
document.getElementsByClassName('search-box')[0].addEventListener('change', loadXMLDoc, false);
} else if (window.attachEvent){
document.getElementsByClassName('search-box')[0].attachEvent("onchange", loadXMLDoc);
}
function loadXMLDoc(){
alert('It worked');
}
}
function addTextCallListener() {
var searchBox = document.getElementsByClassName("search-box")[0];
searchBox.value = "Hello";
}
</script>
</head>
<BODY>
<input type="text" class="search-box" placeholder="Player Search">
<br \>
<button type="button" onclick="addTextCallListener()">Click Me!</button>
</BODY>
</HTML>
I also saved it as this jsfiddle (for some reason I had to keep it all together for it to work, I couldn't break it up into js and html).
https://jsfiddle.net/josephfedor42/crogL0zd/1/
If you play with this jsfiddle you can see that entering text and pressing enter will trigger the listener and the pop up with the message “It worked” will appear.
But if the button “Click Me!” is pressed it only changes the value of the text box, and the onchange listener is not called.
I realize I could easily add an onchange event to this button. But I want to to trigger the listener by programatically/ superficially using javascript in my addTextCallListener() function.
I've tried the simple stuff, like calling
searchBox.onchange();
searchBox.focus();
searchBox.click();
And a combination of these to add and remove the focus. But it doesn't seem to work. I've found quite a few posts on triggering an onchange event, but nothing that works in Firefox.
Any help would be appreciated.
Thanks for that link of a possible duplicated question. I had checked out that link before.
But I gave it a try again. I saved the jsfiddle from them both and neither one work.
My implementation of Dorian's answer
https://jsfiddle.net/josephfedor42/zaakd3dj/
My implementation of Alsciende's answer
https://jsfiddle.net/josephfedor42/xhs6L6u2/
emphasize mine
According to the mdn page about the change event,
The change event is fired for <input>, <select>, and <textarea>
elements when a change to the element's value is committed by the
user.
and to whatwg specs :
When the input and change events apply (which is the case for all
input controls other than buttons and those with the type attribute in
the Hidden state), the events are fired to indicate that the user has
interacted with the control.
Therefore, setting the value of an input is not an action "committed by the user" nor a sign that "the user has interacted with the control", since it was made by the code.
So, even if the specifications for this event are kind of unclear, the event should not fire when you change its value by code.
Something like this should work:
function addTextCallListener() {
var searchBox = document.getElementsByClassName("search-box")[0];
searchBox.value = "Hello";
//fire the event
if (document.createEvent) {
searchBox.dispatchEvent('change');
} else {
searchBox.fireEvent("onchange");
}
}
Here is the code I needed to add to my function addTextCallListener:
var evObj = document.createEvent('HTMLEvents');
evObj.initEvent( 'change', true, true );
searchBox.dispatchEvent(evObj);
I updated the jsfiddle. The working code is here https://jsfiddle.net/josephfedor42/crogL0zd/7/
Replace onchange with change in this part:
document.getElementsByClassName('search-box')[0].attachEvent("onchange", loadXMLDoc);
I have an input text box and a button on a page.
have an onchange event on the text box and an onclick on the button. Each event triggers a totally separate unrelated method.
The problem is as follows:
if the user makes changes to the text box, then right away goes to click on the button - the onchange is triggered but I lose the onclick.
can I avoid this? I need both events to happen.
Thanks
Updated:
I tried a very simple test locally:
<input type="text" onchange="alert1();"/>
<input type="button" onclick="alert2();"/>
where the js is :
<script type="text/javascript">
function alert1()
{
alert("1");
}
function alert2()
{
alert("2");
}
</script>
changing the text and right away clicking on the button only triggers the first event. Is there a way to force the second event to happen?
An alert (along with other modal dialogs) is a bit of a special case, since it suspends execution of the remainder of the script until the user clicks OK. This is why your second handler falls through the cracks.
If you did something like document.write('foo') in your handlers instead, you wouldn't have this problem.
Try this,
function showAlert1() {
setTimeout(function(){ alert("ONE") }, 250);
}
function showAlert2() {
setTimeout(function(){ alert("TWO") }, 250);
}
It buffers the execution of each function so that the button's onclick can be triggered.