Polymer core-input committedValue event - javascript

I'm using the attribute committedValue of core-input element of Polymer like this:
<paper-input is="core-input" type="text" name="data_in" id="data_in" value="{{current_data_in}}" committedValue="{{committed_data_in}}"></paper-input>
It works fine, and it solves the problem of listening to some keypress + blur events to determine the input is "committed".
My problem is that I'd like to erase the contents of the input box value after the value were committed. I can't find any way to listen to this event.
Is there any built-in event that being triggered after a value is committed?

Ok, I found a way to do it and it includes observing the committedValue like this:
<script>
Polymer('chat-element', {
ready: function() {
this.committed_data_in = "";
this.current_data_in = "";
},
observe: {
'committed_data_in': 'modelUpdated'
},
modelUpdated: function(oldValue, newValue) {
console.log(oldValue, newValue);
}
});

Related

HTML onchange event sometimes fires twice on input checkbox element

This happens to me in Chrome 79.0.
CodePen replicating the issue:
https://codepen.io/puckowski/pen/eYmEbVz
I have a basic input element which looks like:
<input type="checkbox">
In JavaScript, I define an onchange property like so:
let eventObj = {
onchange: function() { console.log('event fired'); }
}
I then set my input element's onchange property like so:
for (let [k, v] of Object.entries(eventObj)) {
vType = typeof v;
if (vType === 'function') {
inputElem[k] = v; // inputElem is the correct element in the document and not undefined
}
}
Effectively, inputElem is defined by:
inputElem = document.getElementById('foo');
The onchange event is bound only once per the method above.
When I click on the checkbox, sometimes the onchange event fires once, sometimes it fires twice.
This doesn't seem to be an event bubbling issue. If I change the bound function to the following:
function(evt) { console.log('event fired'); evt.stopPropagation(); }
The onchange event will still fire twice occasionally.
Any ideas as to what is going on? Is this perhaps a element focus issue?
Here is what worked fine for me:
function(evt) {
console.log('event fired');
evt.stopImmediatePropagation();
}

vue.js keyup, keydown events one character behind

I'm using the keydown/keyup events which call a javascript function that prints the value of input box to the console (and also the value of the currentTarget field of the event), and I am noticing it is a character late. For example, if I type hello into the input box, I only see hell in the console, until I press another key and then I see hello, even though by this point I've typed hello1. Why is this? And is there anyway around it?
Here's the HTML:
<input type="text" class="form__field" v-model="keywords" v-on:keyup.enter="queryForKeywords" v-on:keydown="queryForKeywords">
And the JS:
queryForKeywords: function(event) {
var self = this;
if (this.keywords.length > 2) {
console.log("keywords value: " + this.keywords);
console.log("event value: " + event.currentTarget.value);
}
Because you are depending on the input's v-model to update the keywords property, the value won't update until the Vue component has re-rendered.
You can access the updated value of keywords in a callback passed to this.$nextTick like in this example:
new Vue({
el: '#app',
data() {
return { keywords: '' }
},
methods: {
queryForKeywords: function(event) {
this.$nextTick(() => {
if (this.keywords.length > 2) {
console.log("keywords value: " + this.keywords);
}
});
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.min.js"></script>
<div id="app">
<input type="text" class="form__field" v-model="keywords" v-on:keyup.enter="queryForKeywords" v-on:keydown="queryForKeywords">
</div>
The real problem doesn't has to do with vue.js at all
The problem hides behind the keydown event!
So when the event fires, the input value is NOT updated yet. Fiddle example
MDN - keydown event
In general, keydown it is used for informing you which key is pressed. And you can access it like this:
document.addEventListener('keydown', logKey);
function logKey(e) {
console.log(e.key)
}
As solution, you can use the keyup event: Fiddle
My recommendation is to use a custom v-model using :value and the #input event.
<input type="text" :value="keywords" #input="queryForKeywords">
And the script:
data: {
keywords: ''
},
methods: {
queryForKeywords(event) {
const value = event.target.value
this.keywords = value
if (value.length > 2) {
console.log("keywords value: " + this.keywords);
}
}
}
See it in action
The currently accepted answer is for an old version of vue, in the latest versions should be used #input instead of keypress or keyup.

Pure Javascript listen to input value change

Is there any way I can create a constant function that listens to an input, so when that input value changes, something is triggered immediately?
I am looking for something using pure javascript, no plugins, no frameworks and I can't edit the HTML.
Something, for example:
When I change the value in the input MyObject, this function runs.
Any help?
This is what events are for.
HTMLInputElementObject.addEventListener('input', function (evt) {
something(this.value);
});
As a basic example...
HTML:
<input type="text" name="Thing" value="" />
Script:
/* event listener */
document.getElementsByName("Thing")[0].addEventListener('change', doThing);
/* function */
function doThing(){
alert('Horray! Someone wrote "' + this.value + '"!');
}
Here's a fiddle: http://jsfiddle.net/Niffler/514gg4tk/
Actually, the ticked answer is exactly right, but the answer can be in ES6 shape:
HTMLInputElementObject.oninput = () => {
console.log('run'); // Do something
}
Or can be written like below:
HTMLInputElementObject.addEventListener('input', (evt) => {
console.log('run'); // Do something
});
Default usage
el.addEventListener('input', function () {
fn();
});
But, if you want to fire event when you change inputs value manualy via JS you should use custom event(any name, like 'myEvent' \ 'ev' etc.) IF you need to listen forms 'change' or 'input' event and you change inputs value via JS - you can name your custom event 'change' \ 'input' and it will work too.
var event = new Event('input');
el.addEventListener('input', function () {
fn();
});
form.addEventListener('input', function () {
anotherFn();
});
el.value = 'something';
el.dispatchEvent(event);
https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events
Another approach in 2021 could be using document.querySelector():
const myInput = document.querySelector('input[name="exampleInput"]');
myInput.addEventListener("change", (e) => {
// here we do something
});
This sounds exactly like the problem I had.
And I would have stated the same question, but I guess it's the same wrong question...
IMHO it's just 'onchange' mistaken as 'oninput' which are 2 different things.
Give me a lot of minus for this statement, I dont care, but I guess it may help one or the other ...
HTML form input contain many events. Refer from MDN document, on the sidebar go to Events menu and expand it. You will see many useful events such as beforeinput, change, copy, cut, input, paste, and drag drop events.
iput & change.
The beforeinput, and input events are fired by order when you type the form input value.
When the form input value has changed and you lost focus on that input, the change event is fired.
Cut, copy, paste.
When you cut (CTRL+X on keyboard shortcut) the input value, the cut, beforeinput, input events are fired.
When you copy (CTRL+C on keyboard shortcut), the copy event is fired alone.
When you paste the value from clipboard (CTRL+V on keyboard shortcut), the paste, beforeinput, input events are fired.
JS change value.
To change input value by JavaScript and make important events work, you need to dispatch at least 2 events by order. One is input and two is change. So that you can focus your code to listened to input or change event. It's easier this way.
Here is all sample code.
(() => {
let inputText = document.getElementById('text');
let submitBtn = document.getElementById('submit');
let triggerJSBtn = document.getElementById('button');
submitBtn.addEventListener('click', (event) => {
event.preventDefault(); // just prevent form submitted.
});
triggerJSBtn.addEventListener('click', (event) => {
const thisTarget = event.target;
event.preventDefault();
inputText.value = thisTarget.innerText;
inputText.dispatchEvent(new Event('input'));
inputText.dispatchEvent(new Event('change'));
});
inputText.addEventListener('beforeinput', (event) => {
const thisTarget = event.target;
console.log('beforeinput event. (%s)', thisTarget.value);
});
inputText.addEventListener('input', (event) => {
const thisTarget = event.target;
console.log('input event. (%s)', thisTarget.value);
});
inputText.addEventListener('change', (event) => {
const thisTarget = event.target;
console.log('change event. (%s)', thisTarget.value);
});
inputText.addEventListener('cut', (event) => {
const thisTarget = event.target;
console.log('cut event. (%s)', thisTarget.value);
});
inputText.addEventListener('copy', (event) => {
const thisTarget = event.target;
console.log('copy event. (%s)', thisTarget.value);
});
inputText.addEventListener('paste', (event) => {
const thisTarget = event.target;
console.log('paste event. (%s)', thisTarget.value);
});
})();
/* for beautification only */
code {
color: rgb(200, 140, 50);
}
small {
color: rgb(150, 150, 150);
}
<form id="form">
<p>
Text: <input id="text" type="text" name="text">
</p>
<p>
Text 2: <input id="text2" type="text" name="text2"><br>
<small>(For lost focus after modified first input text so the <code>change</code> event will be triggered.)</small>
</p>
<p>
<button id="submit" type="submit">
Submit
</button>
<button id="button" type="button">
Trigger JS to set input value.
</button>
</p>
<p>Press F12 to view results in your browser console.</p>
</form>
Please press F12 to open browser's console and see result there.
Each time a user inputs some value, do something.
var element = document.getElementById('input');
element.addEventListener('input', function() {
// Do something
});
Keydown, keyup, input are events that fire immediately when input changes,
I would use keydown or input events to get the changed value from the input box.
const myObject = document.getElementById('Your_element_id');
myObject.addEventListener('keydown', function (evt) {
// your code goes here
console.log(myObject.value);
});
If you would like to monitor the changes each time there is a keystroke on the keyboard.
const textarea = document.querySelector(`#string`)
textarea.addEventListener("keydown", (e) =>{
console.log('test')
})
instead of id use title to identify your element and write the code as below.
$(document).ready(()=>{
$("input[title='MyObject']").change(()=>{
console.log("Field has been changed...")
})
});

Change-Event for div [duplicate]

I want to run a function when a user edits the content of a div with contenteditable attribute. What's the equivalent of an onchange event?
I'm using jQuery so any solutions that uses jQuery is preferred. Thanks!
2022 update
As pointed out in the comments, this doesn't answer the question asked, which wanted the equivalent of the change event rather than the input event. However, I'll leave it here as is.
Original answer
I'd suggest attaching listeners to key events fired by the editable element, though you need to be aware that keydown and keypress events are fired before the content itself is changed. This won't cover every possible means of changing the content: the user can also use cut, copy and paste from the Edit or context browser menus, so you may want to handle the cut copy and paste events too. Also, the user can drop text or other content, so there are more events there (mouseup, for example). You may want to poll the element's contents as a fallback.
UPDATE 29 October 2014
The HTML5 input event is the answer in the long term. At the time of writing, it is supported for contenteditable elements in current Mozilla (from Firefox 14) and WebKit/Blink browsers, but not IE.
Demo:
document.getElementById("editor").addEventListener("input", function() {
console.log("input event fired");
}, false);
<div contenteditable="true" id="editor">Please type something in here</div>
Demo: http://jsfiddle.net/ch6yn/2691/
Here is a more efficient version which uses on for all contenteditables. It's based off the top answers here.
$('body').on('focus', '[contenteditable]', function() {
const $this = $(this);
$this.data('before', $this.html());
}).on('blur keyup paste input', '[contenteditable]', function() {
const $this = $(this);
if ($this.data('before') !== $this.html()) {
$this.data('before', $this.html());
$this.trigger('change');
}
});
The project is here: https://github.com/balupton/html5edit
Consider using MutationObserver. These observers are designed to react to changes in the DOM, and as a performant replacement to Mutation Events.
Pros:
Fires when any change occurs, which is difficult to achieve by listening to key events as suggested by other answers. For example, all of these work well: drag & drop, italicizing, copy/cut/paste through context menu.
Designed with performance in mind.
Simple, straightforward code. It's a lot easier to understand and debug code that listens to one event rather than code that listens to 10 events.
Google has an excellent mutation summary library which makes using MutationObservers very easy.
Cons:
Requires a very recent version of Firefox (14.0+), Chrome (18+), or IE (11+).
New API to understand
Not a lot of information available yet on best practices or case studies
Learn more:
I wrote a little snippet to compare using MutationObserers to handling a variety of events. I used balupton's code since his answer has the most upvotes.
Mozilla has an excellent page on the API
Take a look at the MutationSummary library
non jQuery quick and dirty answer:
function setChangeListener (div, listener) {
div.addEventListener("blur", listener);
div.addEventListener("keyup", listener);
div.addEventListener("paste", listener);
div.addEventListener("copy", listener);
div.addEventListener("cut", listener);
div.addEventListener("delete", listener);
div.addEventListener("mouseup", listener);
}
var div = document.querySelector("someDiv");
setChangeListener(div, function(event){
console.log(event);
});
I have modified lawwantsin 's answer like so and this works for me. I use the keyup event instead of keypress which works great.
$('#editor').on('focus', function() {
before = $(this).html();
}).on('blur keyup paste', function() {
if (before != $(this).html()) { $(this).trigger('change'); }
});
$('#editor').on('change', function() {alert('changed')});
Two options:
1) For modern (evergreen) browsers:
The "input" event would act as an alternative "change" event.
https://developer.mozilla.org/en-US/docs/Web/Events/input
document.querySelector('div').addEventListener('input', (e) => {
// Do something with the "change"-like event
});
or
<div oninput="someFunc(event)"></div>
or (with jQuery)
$('div').on('click', function(e) {
// Do something with the "change"-like event
});
2) To account for IE11 and modern (evergreen) browsers:
This watches for element changes and their contents inside the div.
https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver
var div = document.querySelector('div');
var divMO = new window.MutationObserver(function(e) {
// Do something on change
});
divMO.observe(div, { childList: true, subtree: true, characterData: true });
const p = document.querySelector('p')
const result = document.querySelector('div')
const observer = new MutationObserver((mutationRecords) => {
result.textContent = mutationRecords[0].target.data
// result.textContent = p.textContent
})
observer.observe(p, {
characterData: true,
subtree: true,
})
<p contenteditable>abc</p>
<div />
Here's what worked for me:
var clicked = {}
$("[contenteditable='true']").each(function(){
var id = $(this).attr("id");
$(this).bind('focus', function() {
// store the original value of element first time it gets focus
if(!(id in clicked)){
clicked[id] = $(this).html()
}
});
});
// then once the user clicks on save
$("#save").click(function(){
for(var id in clicked){
var original = clicked[id];
var current = $("#"+id).html();
// check if value changed
if(original != current) save(id,current);
}
});
This thread was very helpful while I was investigating the subject.
I've modified some of the code available here into a jQuery plugin so it is in a re-usable form, primarily to satisfy my needs but others may appreciate a simpler interface to jumpstart using contenteditable tags.
https://gist.github.com/3410122
Update:
Due to its increasing popularity the plugin has been adopted by Makesites.org
Development will continue from here:
https://github.com/makesites/jquery-contenteditable
Non JQuery answer...
function makeEditable(elem){
elem.setAttribute('contenteditable', 'true');
elem.addEventListener('blur', function (evt) {
elem.removeAttribute('contenteditable');
elem.removeEventListener('blur', evt.target);
});
elem.focus();
}
To use it, call on (say) a header element with id="myHeader"
makeEditable(document.getElementById('myHeader'))
That element will now be editable by the user until it loses focus.
In Angular 2+
<div contentEditable (input)="type($event)">
Value
</div>
#Component({
...
})
export class ContentEditableComponent {
...
type(event) {
console.log(event.data) // <-- The pressed key
console.log(event.path[0].innerHTML) // <-- The content of the div
}
}
To avoid timers and "save" buttons, you may use blur event wich fires when the element loses focus. but to be sure that the element was actually changed (not just focused and defocused), its content should be compared against its last version. or use keydown event to set some "dirty" flag on this element.
Here is the solution I ended up using and works fabulously. I use $(this).text() instead because I am just using a one line div that is content editable. But you may also use .html() this way you dont have to worry about the scope of a global/non-global variable and the before is actually attached to the editor div.
$('body').delegate('#editor', 'focus', function(){
$(this).data('before', $(this).html());
});
$('#client_tasks').delegate('.task_text', 'blur', function(){
if($(this).data('before') != $(this).html()){
/* do your stuff here - like ajax save */
alert('I promise, I have changed!');
}
});
You need to use input event type
Demo
HTML
<div id="editor" contenteditable="true" >Some text here</div>
JS
const input = document.getElementById('editor');
input.addEventListener('input', updateValue);
function updateValue(e) {
console.log(e.target);
}
know more
The onchange event doesn't fires when an element with the contentEditable attribute is changed, a suggested approach could be to add a button, to "save" the edition.
Check this plugin which handles the issue in that way:
Creating a quick and dirty jQuery contentEditable Plugin
Using DOMCharacterDataModified under MutationEvents will lead to the same. The timeout is setup to prevent sending incorrect values (e.g. in Chrome I had some issues with space key)
var timeoutID;
$('[contenteditable]').bind('DOMCharacterDataModified', function() {
clearTimeout(timeoutID);
$that = $(this);
timeoutID = setTimeout(function() {
$that.trigger('change')
}, 50)
});
$('[contentEditable]').bind('change', function() {
console.log($(this).text());
})
JSFIDDLE example
I built a jQuery plugin to do this.
(function ($) {
$.fn.wysiwygEvt = function () {
return this.each(function () {
var $this = $(this);
var htmlold = $this.html();
$this.bind('blur keyup paste copy cut mouseup', function () {
var htmlnew = $this.html();
if (htmlold !== htmlnew) {
$this.trigger('change')
}
})
})
}
})(jQuery);
You can simply call $('.wysiwyg').wysiwygEvt();
You can also remove / add events if you wish
A simple answer in JQuery, I just created this code and thought it will be helpful for others too
var cont;
$("div [contenteditable=true]").focus(function() {
cont=$(this).html();
});
$("div [contenteditable=true]").blur(function() {
if ($(this).html()!=cont) {
//Here you can write the code to run when the content change
}
});
For me, I want to check the input is valid or not.
If valid, then update, Otherwise show an error message and keep the value as same as before.
Skill: When you edit done, usually, it will trigger the blur event.
Example
<span contenteditable="true">try input somethings.</span>
<script>
const elem = document.querySelector(`span`)
let oldValue = elem.innerText
elem.onkeydown = (keyboardEvent) => {
if (keyboardEvent.key === "Enter") {
elem.blur() // set focusout
}
}
elem.onblur = (e) => {
const curValue = elem.innerText
if (curValue === oldValue) {
return
}
if (curValue.length <= 50) { // 👈 Input your conditions.
// 👇 fail
elem.innerText = oldValue
// (Optional) Add error message
elem.insertAdjacentHTML("beforeend", `<span style="margin-left:5px;color:red">error length=${curValue.length}. Must greater than 50. undo to the previous value.</span>`)
const errMsg = elem.querySelector(`span`)
setTimeout(() => errMsg.remove(), 3500) // wait 3.5 second, and then remove it.
return
}
// 👇 OK, update
oldValue = curValue
}
</script>
Check this idea out.
http://pastie.org/1096892
I think it's close. HTML 5 really needs to add the change event to the spec. The only problem is that the callback function evaluates if (before == $(this).html()) before the content is actually updated in $(this).html(). setTimeout don't work, and it's sad. Let me know what you think.
Based on #balupton's answer:
$(document).on('focus', '[contenteditable]', e => {
const self = $(e.target)
self.data('before', self.html())
})
$(document).on('blur', '[contenteditable]', e => {
const self = $(e.target)
if (self.data('before') !== self.html()) {
self.trigger('change')
}
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

javascript: How to clean an input box when another input value changed?

I made one input (#child)auto suggestion base on another input(#parent). When the #parent input value changed, I want to clean the #child's value. I would like to learn how to do this, thanks!
You could subscribe to the onchange event of the parent and then clear the value of the child:
window.onload = function() {
// the document has loaded => we could access the DOM
// we subscribe to the onchange event pf the parent:
document.getElementById('parentId').onchange = function() {
// and when this event is triggered we clean the child
// element value
document.getElementById('childId').value = '';
};
};

Categories

Resources