当用户完成键入而不是按键时运行 javascript function？

Question

I want to trigger an ajax request when the user has finished typing in a text box. I don't want it to run the function on every time the user types a letter because that would result in A LOT of ajax requests, however I don't want them to have to hit the enter button either.

Is there a way so I can detect when the user has finished typing and then do the ajax request?

Using jQuery here!

Answer 1

So, I'm going to guess finish typing means you just stop for a while, say 5 seconds. So with that in mind, let's start a timer when the user releases a key and clear it when they press one. I decided the input in question will be #myInput.

Making a few assumptions...

//setup before functions
var typingTimer;                //timer identifier
var doneTypingInterval = 5000;  //time in ms, 5 seconds for example
var $input = $('#myInput');

//on keyup, start the countdown
$input.on('keyup', function () {
  clearTimeout(typingTimer);
  typingTimer = setTimeout(doneTyping, doneTypingInterval);
});

//on keydown, clear the countdown 
$input.on('keydown', function () {
  clearTimeout(typingTimer);
});

//user is "finished typing," do something
function doneTyping () {
  //do something
}

Answer 2

The chosen answer above does not work.

Because typingTimer is occassionaly set multiple times (keyup pressed twice before keydown is triggered for fast typers etc.) then it doesn't clear properly.

The solution below solves this problem and will call X seconds after finished as the OP requested. It also no longer requires the redundant keydown function. I have also added a check so that your function call won't happen if your input is empty.

//setup before functions
var typingTimer;                //timer identifier
var doneTypingInterval = 5000;  //time in ms (5 seconds)

//on keyup, start the countdown
$('#myInput').keyup(function(){
    clearTimeout(typingTimer);
    if ($('#myInput').val()) {
        typingTimer = setTimeout(doneTyping, doneTypingInterval);
    }
});

//user is "finished typing," do something
function doneTyping () {
    //do something
}

And the same code in vanilla JavaScript solution:

//setup before functions
let typingTimer;                //timer identifier
let doneTypingInterval = 5000;  //time in ms (5 seconds)
let myInput = document.getElementById('myInput');

//on keyup, start the countdown
myInput.addEventListener('keyup', () => {
    clearTimeout(typingTimer);
    if (myInput.value) {
        typingTimer = setTimeout(doneTyping, doneTypingInterval);
    }
});

//user is "finished typing," do something
function doneTyping () {
    //do something
}

This solution does use ES6 but it's not necessary here. Just replace let with var and the arrow function with a regular function.

Answer 3

It's just one line with underscore.js debounce function:

$('#my-input-box').keyup(_.debounce(doSomething , 500));

This basically says doSomething 500 milliseconds after I stop typing.

For more info: http://underscorejs.org/#debounce

Answer 4

Late answer but I'm adding it because it's 2019 and this is entirely achievable using pretty ES6, no third party libraries, and I find most of the highly rated answers are bulky and weighed down with too many variables.

Elegant solution taken from this excellent blog post.

function debounce(callback, wait) {
  let timeout;
  return (...args) => {
      clearTimeout(timeout);
      timeout = setTimeout(function () { callback.apply(this, args); }, wait);
  };
}

window.addEventListener('keyup', debounce( () => {
    // code you would like to run 1000ms after the keyup event has stopped firing
    // further keyup events reset the timer, as expected
}, 1000))

Answer 5

Yes, you can set a timeout of say 2 seconds on each and every key up event which will fire an ajax request. You can also store the XHR method and abort it on subsequent key press events so that you save bandwith even more. Here's something I've written for an autocomplete script of mine.

var timer;
var x;

$(".some-input").keyup(function () {
    if (x) { x.abort() } // If there is an existing XHR, abort it.
    clearTimeout(timer); // Clear the timer so we don't end up with dupes.
    timer = setTimeout(function() { // assign timer a new timeout 
        x = $.getJSON(...); // run ajax request and store in x variable (so we can cancel)
    }, 2000); // 2000ms delay, tweak for faster/slower
});

Hope this helps,

Marko

Answer 6

var timer;
var timeout = 1000;

$('#in').keyup(function(){
    clearTimeout(timer);
    if ($('#in').val) {
        timer = setTimeout(function(){
            //do stuff here e.g ajax call etc....
             var v = $("#in").val();
             $("#out").html(v);
        }, timeout);
    }
});

full example here: http://jsfiddle.net/ZYXp4/8/

Answer 7

Both top 2 answers doesn't work for me. So, here is my solution:

var timeout = null;

$('#myInput').keyup(function() {
    clearTimeout(timeout);

    timeout = setTimeout(function() {
        //do stuff here
    }, 500);
});

Answer 8

Modifying the accepted answer to handle additional cases such as paste:

//setup before functions
var typingTimer;                //timer identifier
var doneTypingInterval = 2000;  //time in ms, 2 second for example
var $input = $('#myInput');

// updated events 
$input.on('input propertychange paste', function () {
    clearTimeout(typingTimer);
    typingTimer = setTimeout(doneTyping, doneTypingInterval);      
});

//user is "finished typing," do something
function doneTyping () {
  //do something
}

Answer 9

Declare the following delay function:

var delay = (function () {
    var timer = 0;
    return function (callback, ms) {
        clearTimeout(timer);
        timer = setTimeout(callback, ms);
    };
})()

and then use it:

let $filter = $('#item-filter');
$filter.on('keydown', function () {
    delay(function () {            
        console.log('this will hit, once user has not typed for 1 second');            
    }, 1000);
});    

Answer 10

I like Surreal Dream's answer but I found that my "doneTyping" function would fire for every keypress, ie if you type "Hello" really quickly; instead of firing just once when you stop typing, the function would fire 5 times.

The problem was that the javascript setTimeout function doesn't appear to overwrite or kill the any old timeouts that have been set, but if you do it yourself it works! So I just added a clearTimeout call just before the setTimeout if the typingTimer is set. See below:

//setup before functions
var typingTimer;                //timer identifier
var doneTypingInterval = 5000;  //time in ms, 5 second for example

//on keyup, start the countdown
$('#myInput').on("keyup", function(){
    if (typingTimer) clearTimeout(typingTimer);                 // Clear if already set     
    typingTimer = setTimeout(doneTyping, doneTypingInterval);
});

//on keydown, clear the countdown 
$('#myInput').on("keydown", function(){
    clearTimeout(typingTimer);
});

//user is "finished typing," do something
function doneTyping () {
    //do something
}

NB I would have liked to have just added this as a comment to Surreal Dream's answer but I'm a new user and don't have enough reputation. Sorry!

Answer 11

I don't think keyDown event is necessary in this case (please tell me why if I'm wrong). In my (non-jquery) script similar solution looks like that:

var _timer, _timeOut = 2000; 



function _onKeyUp(e) {
    clearTimeout(_timer);
    if (e.keyCode == 13) {      // close on ENTER key
        _onCloseClick();
    } else {                    // send xhr requests
        _timer = window.setTimeout(function() {
            _onInputChange();
        }, _timeOut)
    }

}

It's my first reply on Stack Overflow, so I hope this helps someone, someday:)

Answer 12

I was implementing the search at my listing and needed it to be ajax based. That means that on every key change, searched results should be updated and displayed. This results in so many ajax calls sent to server, which is not a good thing.

After some working, I made an approach to ping the server when the user stops typing.

This solution worked for me:

$(document).ready(function() {
    $('#yourtextfield').keyup(function() {
        s = $('#yourtextfield').val();
        setTimeout(function() { 
            if($('#yourtextfield').val() == s){ // Check the value searched is the latest one or not. This will help in making the ajax call work when client stops writing.
                $.ajax({
                    type: "POST",
                    url: "yoururl",
                    data: 'search=' + s,
                    cache: false,
                    beforeSend: function() {
                       // loading image
                    },
                    success: function(data) {
                        // Your response will come here
                    }
                })
            }
        }, 1000); // 1 sec delay to check.
    }); // End of  keyup function
}); // End of document.ready

You will notice that there is no need to use any timer while implementing this.

Answer 13

agree with the @going 's answer. Another similar solution that worked for me is the one below. The only difference is that I am using .on("input"...) instead of keyup. This only captures changes in the input. other keys like Ctrl, Shift etc. are ignored

var typingTimer;                //timer identifier
var doneTypingInterval = 5000;  //time in ms (5 seconds)

//on input change, start the countdown

$('#myInput').on("input", function() {    
    clearTimeout(typingTimer);
    typingTimer = setTimeout(function(){
        // doSomething...
    }, doneTypingInterval);
});

Answer 14

I feel like the solution is somewhat a bit simpler with the input event:

var typingTimer;
var doneTypingInterval = 500;

$("#myInput").on("input", function () {
    window.clearTimeout(typingTimer);
    typingTimer = window.setTimeout(doneTyping, doneTypingInterval);
});

function doneTyping () {
    // code here
}

Answer 15

Well, strictly speaking no, as the computer cannot guess when the user has finished typing. You could of course fire a timer on key up, and reset it on every subsequent key up. If the timer expires, the user hasn't typed for the timer duration - you could call that "finished typing".

If you expect users to make pauses while typing, there's no way to know when they are done.

(Unless of course you can tell from the data when they are done)

Answer 16

I just figured out a simple code to wait for user to finish typing:

step 1.set time out to null then clear the current timeout when the user is typing.

step 2.trigger clear timeout to the variable define before keyup event is triggered.

step 3.define timeout to the variable declared above;

<input type="text" id="input" placeholder="please type" style="padding-left:20px;"/>
<div class="data"></div>

javascript code

var textInput = document.getElementById('input');
var textdata = document.querySelector('.data');
// Init a timeout variable to be used below
var timefired = null;

// Listen for keystroke events
// Init a timeout variable to be used below
var timefired = null;// Listen for keystroke events
textInput.onkeyup = function (event) {
clearTimeout(timefired);
timefired = setTimeout(function () {
    textdata.innerHTML = 'Input Value:'+ textInput.value;
  }, 600);
};

Answer 17

 const inText = document.getElementById('inText') const outText = document.getElementById('outText') const delay = 1000 let timer inText.addEventListener('input', code => { clearTimeout(timer); timer = setTimeout(x => { outText.innerHTML = inText.value }, delay, code) })

 <textarea id='inText'>edit this and...</textarea> <pre id='outText'>see the results after you stop typing for one second</pre>

Answer 18

This is the a simple JS code I wrote:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="pt-br" lang="pt-br">
<head><title>Submit after typing finished</title>
<script language="javascript" type="text/javascript">
function DelayedSubmission() {
    var date = new Date();
    initial_time = date.getTime();
    if (typeof setInverval_Variable == 'undefined') {
            setInverval_Variable = setInterval(DelayedSubmission_Check, 50);
    } 
}
function DelayedSubmission_Check() {
    var date = new Date();
    check_time = date.getTime();
    var limit_ms=check_time-initial_time;
    if (limit_ms > 800) { //Change value in milliseconds
        alert("insert your function"); //Insert your function
        clearInterval(setInverval_Variable);
        delete setInverval_Variable;
    }
}

</script>
</head>
<body>

<input type="search" onkeyup="DelayedSubmission()" id="field_id" style="WIDTH: 100px; HEIGHT: 25px;" />

</body>
</html>

Answer 19

Why not just use onfocusout?

https://www.w3schools.com/jsreF/event_onfocusout.asp

If it's a form, they will always leave focus of every input field in order to click the submit button so you know no input will miss out on getting its onfocusout event handler called.

Answer 20

You can use the onblur event to detect when the textbox loses focus: https://developer.mozilla.org/en/DOM/element.onblur

That's not the same as "stops typing", if you care about the case where the user types a bunch of stuff and then sits there with the textbox still focused.

For that I would suggest tying a setTimeout to the onclick event, and assuming that after x amount of time with no keystrokes, the user has stopped typing.

Answer 21

Multiple timers per page

All the other answers only work for one control ( my other answer included). If you have multiple controls per page (eg in a shopping cart) only the last control where the user typed something will get called . In my case this is certainly not the wished behaviour - each control should have its own timer.

To solve this, you simply have to pass an ID to the function and maintain a timeoutHandles dictionary as in the following code:

Function Declaration:

var delayUserInput = (function () {
    var timeoutHandles = {};    
    return function (id, callback, ms) {        
        if (timeoutHandles[id]) {
            clearTimeout(timeoutHandles[id]);
        }

        timeoutHandles[id] = setTimeout(callback, ms);             
    };
})();

Function Usage:

  delayUserInput('yourID', function () {
     //do some stuff
  }, 1000);

Answer 22

If there is necessity for the user to move away from the field, we can use "onBlur" instead of Onchange in Javascript

  <TextField id="outlined-basic"  variant="outlined" defaultValue={CardValue} onBlur={cardTitleFn} />

If that is not necessary setting timer would be the good option.

Answer 23

If you are looking for a specific length (such as a zipcode field):

$("input").live("keyup", function( event ){
if(this.value.length == this.getAttribute('maxlength')) {
        //make ajax request here after.
    }
  });

Answer 24

Not sure if my needs are just kind of weird, but I needed something similar to this and this is what I ended up using:

$('input.update').bind('sync', function() {
    clearTimeout($(this).data('timer'));            
    $.post($(this).attr('data-url'), {value: $(this).val()}, function(x) {
        if(x.success != true) {
            triggerError(x.message);    
        }
    }, 'json');
}).keyup(function() {
    clearTimeout($(this).data('timer'));
    var val = $.trim($(this).val());
    if(val) {
        var $this = $(this);
        var timer = setTimeout(function() {
            $this.trigger('sync');
        }, 2000);
        $(this).data('timer', timer);
    }
}).blur(function() {
    clearTimeout($(this).data('timer'));     
    $(this).trigger('sync');
});

Which allows me to have elements like this in my application:

<input type="text" data-url="/controller/action/" class="update">

Which get updated when the user is "done typing" (no action for 2 seconds) or goes to another field (blurs out of the element)

Answer 25

If you need wait until user is finished with typing use simple this:

$(document).on('change','#PageSize', function () {
    //Do something after new value in #PageSize       
});

Complete Example with ajax call - this working for my pager - count of item per list:

$(document).ready(function () {
    $(document).on('change','#PageSize', function (e) {
        e.preventDefault();
        var page = 1;
        var pagesize = $("#PageSize").val();
        var q = $("#q").val();
        $.ajax({
            url: '@Url.Action("IndexAjax", "Materials", new { Area = "TenantManage" })',
            data: { q: q, pagesize: pagesize, page: page },
            type: 'post',
            datatype: "json",
            success: function (data) {
                $('#tablecontainer').html(data);
               // toastr.success('Pager has been changed', "Success!");
            },
            error: function (jqXHR, exception) {
                ShowErrorMessage(jqXHR, exception);
            }
        });  
    });
});    

Answer 26

Once you detect focus on the text box, on key up do a timeout check, and reset it each time it's triggered.

When the timeout completes, do your ajax request.

Answer 27

Simple and easy to understand.

var mySearchTimeout;
$('#ctl00_mainContent_CaseSearch').keyup(function () {
   clearTimeout(mySearchTimeout);
   var filter = $(this).val();
   mySearchTimeout = setTimeout(function () { myAjaxCall(filter); }, 700);
   return true;
});

Answer 28

For passing parameters to your function along with ES6 syntax.

$(document).ready(() => {
    let timer = null;
     $('.classSelector').keydown(() => {
     clearTimeout(timer); 
     timer = setTimeout(() => foo('params'), 500);
  });
});

const foo = (params) => {
  console.log(`In foo ${params}`);
}

Answer 29

Not a direct answer bu if someone looking for an AngularJS solution. I wrote a directive according to the popular solutions here.

 app.directive("ngTypeEnds", ["$timeout", function ($timeout) {
    return function (scope, element, attrs) {
        var typingTimer;               
        element.bind("keyup", function (event) {
            if (typingTimer)
                $timeout.cancel(typingTimer);
            if (angular.element(element)[0].value) {
                typingTimer = $timeout(function () {
                    scope.$apply(function () {
                        scope.$eval(attrs.ngTypeEnds);
                    });
                }, 500);
            }
            event.preventDefault();
        });
    };
}]);

Answer 30

You guys have heard of closures in javascript ?!

it's very simple and straightforward just compare you current input value with the old value that the setTimeOut function closes over, and voila, you're done.

let timer;
$('#myInput').on('keyup', function() {
  window.clearTimeout(timer);
  // here is the closures javascript magic happens.
  const value = $(this).val();
  timer = setTimeout(() => {
    if(value === $(this).val() && $(this).val()!== ''){
        alert($(this).val());
    }
  }, 500);
})

Answer 31

I needed mine to run for a specific control and this worked for me :

function debounce(func, timeout) {
            let timer;
            return (...args) => {
                clearTimeout(timer);
                timer = setTimeout(() => { func.apply(this, args); }, timeout);
            };
        }

$('#txtFilterClientCode').keyup(debounce(function () {
            console.log("Test");
        }, 1000));

Answer 32

Here is a solution that fires after 1 second of not typing, but also fires instantly when the input is blank. This is useful when clearing search results after the user deletes the input query. This solution also supports copying and pasting into the search box. The $(() => { ... }); wrapping the top portion of code simply means "do this when the page is loaded" in simple Jquery terms.

var searchTimer;
var searchInterval = 1000;

$(() => {
    $('#search-box').on('input', (event) => {
        clearTimeout(searchTimer);
        searchTimer = setTimeout(() => {
            searchContacts(event.target.value);
        }, (event.target.value.length > 0) ? searchInterval : 0);
    });
});

function searchContacts(val) {
    console.log('searching: ' + val);
}

Answer 33

for alpine.js users <input @input.debounce.500ms="fn()">

Answer 34

Wow, even 3 comments are pretty correct!

1. Empty input is not a reason to skip function call, eg I remove waste parameter from url before redirect

2. .on ('input', function() { ... }); should be used to trigger keyup , paste and change events

3. definitely .val() or .value must be used

4. You can use $(this) inside event function instead of #id to work with multiple inputs

5. (my decision) I use anonymous function instead of doneTyping in setTimeout to easily access $(this) from n.4, but you need to save it first like var $currentInput = $(this);

EDIT I see that some people don't understand directions without the possibility to copy-paste ready code. Here you're

var typingTimer;
//                  2
$("#myinput").on('input', function () {
    //             4     3
    var input = $(this).val();
    clearTimeout(typingTimer);
    //                           5
    typingTimer = setTimeout(function() {
        // do something with input
        alert(input);
    }, 5000);      
});