Is it possible to bind javascript (jQuery is best) event to &quot;change&quot; form input value somehow? 

I know about `.change()` method, but it does not trigger until you (the cursor) leave(s) the input field. I have also considered using `.keyup()` method but it reacts also on arrow keys and so on. 

I need just trigger an action **every time** the text in the input changes, even if it&#39;s only one letter change.

Can jQuery check whether input content has changed?

When I played with `&lt;input type=&quot;range&quot;&gt;`, Firefox triggers an onchange event only if we drop the slider to a new position where Chrome and others triggers onchange events while the slider is dragged.

How can I make it happen on dragging in Firefox?

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    function showVal(newVal){
        document.getElementById(&quot;valBox&quot;).innerHTML=newVal;
    }

&lt;!-- language: lang-html --&gt;

    &lt;span id=&quot;valBox&quot;&gt;&lt;/span&gt;
    &lt;input type=&quot;range&quot; min=&quot;5&quot; max=&quot;10&quot; step=&quot;1&quot; onchange=&quot;showVal(this.value)&quot;&gt;

&lt;!-- end snippet --&gt;



onchange event on input type=range is not triggering in firefox while dragging

I have a hidden text field whose value gets updated via an AJAX response.

    &lt;input type=&quot;hidden&quot; value=&quot;&quot; name=&quot;userid&quot; id=&quot;useid&quot; /&gt;

When this value changes, I would like to fire an AJAX request. Can anyone advise on how to detect the change?

I have the following code, but do not know how to look for the value:

    $(&#39;#userid&#39;).change( function() {  
       	alert(&#39;Change!&#39;); 
    }) 

jQuery - Detect value change on hidden input field

I want to fire the JQuery `change` event when the input text is changed programmatically, for example like this:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    $(&quot;input&quot;).change(function(){
        console.log(&quot;Input text changed!&quot;);
    });
    $(&quot;input&quot;).val(&quot;A&quot;);

&lt;!-- language: lang-html --&gt;

    &lt;script src=&quot;https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js&quot;&gt;&lt;/script&gt;
    &lt;input type=&#39;text&#39; /&gt;

&lt;!-- end snippet --&gt;

But it doesn&#39;t work. How can I make this work? 
    
    

How to fire JQuery change event when input value changed programmatically?

I need to be able to run a function after a selection in made in a `&lt;select&gt;`.  The issue is I&#39;m also binding with @bind and I get a error when I try to use @onchange stating that it is already in use by the @bind.  I tried using @onselectionchange, but that does nothing(doesn&#39;t run the function).  I could forget the @bind and just assign @onchange to a function, but I&#39;m not sure how to pass the selected value to the function. 

I have the following code:

    &lt;select @bind=&quot;@SelectedCustID&quot; @ @onchange=&quot;@CustChanged&quot; class=&quot;form-control&quot;&gt;
        @foreach (KeyGuidPair i in CustList)
        {
            &lt;option value=&quot;@i.Value&quot;&gt;@i.Text&lt;/option&gt;
        }
    &lt;/select&gt;

Thanks.

Blazor: How to use the onchange event in &lt;select&gt; when using @bind also?

In my project I have an `EditText`. I want to count the characters in the `EditText`, and show that number it in a `TextView`. I have written the following code and it works fine. However, my problem is when I click &lt;kbd&gt;Backspace&lt;/kbd&gt; it counts up, but I need to decrement the number. How can I consider &lt;kbd&gt;Backspace&lt;/kbd&gt;?

    tv = (TextView)findViewById(R.id.charCounts);
    textMessage = (EditText)findViewById(R.id.textMessage);
    textMessage.addTextChangedListener(new TextWatcher(){
    	public void afterTextChanged(Editable s) {
    		i++;
    		tv.setText(String.valueOf(i) + &quot; / &quot; + String.valueOf(charCounts));
        }
        public void beforeTextChanged(CharSequence s, int start, int count, int after){}
        public void onTextChanged(CharSequence s, int start, int before, int count){}
    }); 

Counting Chars in EditText Changed Listener

I am a novice at JavaScript and jQuery. I want to show one combobox-A, which is an HTML `&lt;select&gt;` with its selected `id` and contents at the other place on onChange(). 

How can I pass the complete combobox with its select `id`, and how can I pass other parameters on fire of the onChange event?

How to pass parameters on onChange of html select

`&lt;select&gt;` has this API. What about `&lt;input&gt;`?


How do I implement onchange of &lt;input type=&quot;text&quot;&gt; with jQuery?

TLDR: Use defaultChecked instead of checked, working [jsbin][1].

Trying to setup a simple checkbox that will cross out its label text when it is checked.  For some reason handleChange is not getting fired when I use the component.  Can anyone explain what I&#39;m doing wrong?

&lt;!-- language: lang-js --&gt;

    var CrossoutCheckbox = React.createClass({
      getInitialState: function () {
        return {
            complete: (!!this.props.complete) || false
          };
      },
      handleChange: function(){
        console.log(&#39;handleChange&#39;, this.refs.complete.checked); // Never gets logged
        this.setState({
          complete: this.refs.complete.checked
        });
      },
      render: function(){
        var labelStyle={
          &#39;text-decoration&#39;: this.state.complete?&#39;line-through&#39;:&#39;&#39;
        };
        return (
          &lt;span&gt;
            &lt;label style={labelStyle}&gt;
              &lt;input
                type=&quot;checkbox&quot;
                checked={this.state.complete}
                ref=&quot;complete&quot;
                onChange={this.handleChange}
              /&gt;
              {this.props.text}
            &lt;/label&gt;
          &lt;/span&gt;
        );
      }
    });

Usage:

&lt;!-- language: lang-js --&gt;

    React.renderComponent(CrossoutCheckbox({text: &quot;Text Text&quot;, complete: false}), mountNode);

Solution:

Using checked doesn&#39;t let the underlying value change (apparently) and thus doesn&#39;t call the onChange handler.  Switching to defaultChecked seems to fix this:

&lt;!-- language: lang-js --&gt;

    var CrossoutCheckbox = React.createClass({
      getInitialState: function () {
        return {
            complete: (!!this.props.complete) || false
          };
      },
      handleChange: function(){
        this.setState({
          complete: !this.state.complete
        });
      },
      render: function(){
        var labelStyle={
          &#39;text-decoration&#39;: this.state.complete?&#39;line-through&#39;:&#39;&#39;
        };
        return (
          &lt;span&gt;
            &lt;label style={labelStyle}&gt;
              &lt;input
                type=&quot;checkbox&quot;
                defaultChecked={this.state.complete}
                ref=&quot;complete&quot;
                onChange={this.handleChange}
              /&gt;
              {this.props.text}
            &lt;/label&gt;
          &lt;/span&gt;
        );
      }
    });


  [1]: http://jsbin.com/mecimayawe/1/edit?js,output

React Checkbox not sending onChange

What is the easiest and best way to trigger **change** event when setting the value of **select** element.

I&#39;ve expected that executing the following code

    $(&#39;select#some&#39;).val(10);

or

    $(&#39;select#some&#39;).attr(&#39;value&#39;,  10);

would result in triggering the change event, which i think is pretty logic thing to be done. Right?

Well, it isn&#39;t the case. You need to triger change() event by doing this

    $(&#39;select#some&#39;).val(10).change();

or

    $(&#39;select#some&#39;).val(10).trigger(&#39;change&#39;);

but i&#39;m looking for some solution which would trigger change event as soon as select&#39;s value is changed by some javascript code.



Trigger change() event when setting &lt;select&gt;&#39;s value with val() function

    setOnCheckedChangeListener(new OnCheckedChangeListener() {
    			@Override
    			public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    				// How to check whether the checkbox/switch has been checked
    				// by user or it has been checked programatically ?
    
    				if (isNotSetByUser())
    					return;
    				handleSetbyUser();
    			}
    		});

How to implement method `isNotSetByUser()`?


How can I distinguish whether Switch,Checkbox Value is changed by user or programmatically (including by retention)?

What would be the best way to attach an event so on change of a select option a URL. Store the href in an attr and grab it on change?

Onchange open URL via select - jQuery

I&#39;m trying to develop a TextField that update the data on a Firestore database when they change. It seems to work but I need to prevent the onChange event to fire multiple times.

In JS I would use lodash _debounce() but in Dart I don&#39;t know how to do it. I&#39;ve read of some debounce libraries but I can&#39;t figure out how they work.

That&#39;s my code, it&#39;s only a test so something may be strange:

    import &#39;package:flutter/material.dart&#39;;
    import &#39;package:cloud_firestore/cloud_firestore.dart&#39;;
    
    
    class ClientePage extends StatefulWidget {
    
      String idCliente;
    
    
      ClientePage(this.idCliente);
    
      @override
      _ClientePageState createState() =&gt; new _ClientePageState();
    
      
    }
    
    class _ClientePageState extends State&lt;ClientePage&gt; {
    
      TextEditingController nomeTextController = new TextEditingController();
    
    
      void initState() {
        super.initState();
    
        // Start listening to changes 
        nomeTextController.addListener(((){
            _updateNomeCliente(); // &lt;- Prevent this function from run multiple times
        }));
      }
    
    
      _updateNomeCliente = (){
    
        print(&quot;Aggiorno nome cliente&quot;);
        Firestore.instance.collection(&#39;clienti&#39;).document(widget.idCliente).setData( {
          &quot;nome&quot; : nomeTextController.text
        }, merge: true);
    
      }
    
    
    
      @override
      Widget build(BuildContext context) {
    
        return new StreamBuilder&lt;DocumentSnapshot&gt;(
          stream: Firestore.instance.collection(&#39;clienti&#39;).document(widget.idCliente).snapshots(),
          builder: (BuildContext context, AsyncSnapshot&lt;DocumentSnapshot&gt; snapshot) {
            if (!snapshot.hasData) return new Text(&#39;Loading...&#39;);
    
            nomeTextController.text = snapshot.data[&#39;nome&#39;];
    
    
            return new DefaultTabController(
              length: 3,
              child: new Scaffold(
                body: new TabBarView(
                  children: &lt;Widget&gt;[
                    new Column(
                      children: &lt;Widget&gt;[
                        new Padding(
                          padding: new EdgeInsets.symmetric(
                            vertical : 20.00
                          ),
                          child: new Container(
                            child: new Row(
                              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                              children: &lt;Widget&gt;[
                                new Text(snapshot.data[&#39;cognome&#39;]),
                                new Text(snapshot.data[&#39;ragionesociale&#39;]),
                              ],
                            ),
                          ),
                        ),
                        new Expanded(
                          child: new Container(
                            decoration: new BoxDecoration(
                              borderRadius: BorderRadius.only(
                                topLeft: Radius.circular(20.00),
                                topRight: Radius.circular(20.00)
                              ),
                              color: Colors.brown,
                            ),
                            child: new ListView(
                              children: &lt;Widget&gt;[
                                new ListTile(
                                  title: new TextField(
                                    style: new TextStyle(
                                      color: Colors.white70
                                    ),
                                    controller: nomeTextController,
                                    decoration: new InputDecoration(labelText: &quot;Nome&quot;)
                                  ),
                                )
                              ]
                            )
                          ),
                        )
                      ],
                    ),
                    new Text(&quot;La seconda pagina&quot;),
                    new Text(&quot;La terza pagina&quot;),
                  ]
                ),
                appBar: new AppBar(
                  title: Text(snapshot.data[&#39;nome&#39;] + &#39; oh &#39; + snapshot.data[&#39;cognome&#39;]),
                  bottom: new TabBar(          
                    tabs: &lt;Widget&gt;[
                      new Tab(text: &quot;Informazioni&quot;),  // 1st Tab
                      new Tab(text: &quot;Schede cliente&quot;), // 2nd Tab
                      new Tab(text: &quot;Altro&quot;), // 3rd Tab
                    ],
                  ),
                ),
              )
            );
            
          },
        );
    
        print(&quot;Il widget id &#232;&quot;);
        print(widget.idCliente);
        
      }
    }





How to debounce Textfield onChange in Dart?

**What I&#39;m trying to do:**

I am trying to pass a string from a child component to the handleChange function of a parent component.

**What currently works:**

I have a parent React JS class with the following method:

    handleChange(event) {
  
        console.log(event.target.value);
    }

In the render function I have the following:

    &lt;Child handleChange={this.handleChange.bind(this)} /&gt;

In the Child class I have:

    &lt;fieldset onChange={this.props.handleChange}&gt;
        &lt;div&gt;Tag 1: &lt;input id=&quot;tag1&quot; value={tags[0]} /&gt;&lt;/div&gt;
        &lt;div&gt;Tag 2: &lt;input id=&quot;tag2&quot; value={tags[1]} /&gt;&lt;/div&gt;
        &lt;div&gt;Tag 3: &lt;input id=&quot;tag3&quot; value={tags[2]} /&gt;&lt;/div&gt;
    &lt;/fieldset&gt;

This works fine.

**What I am trying to do instead:**

I am attempting to add a `section` parameter to the handleChange function as follows:

    handleChange(section, event) {
        console.log(section);
        console.log(event.target.value);
    }

And in the Child class I have:

    &lt;fieldset onChange={this.props.handleChange(&quot;tags&quot;)}&gt;
        &lt;div&gt;Tag 1: &lt;input id=&quot;tag1&quot; value={tags[0]} /&gt;&lt;/div&gt;
        &lt;div&gt;Tag 2: &lt;input id=&quot;tag2&quot; value={tags[1]} /&gt;&lt;/div&gt;
        &lt;div&gt;Tag 3: &lt;input id=&quot;tag3&quot; value={tags[2]} /&gt;&lt;/div&gt;
    &lt;/fieldset&gt;

I now get the error:

    Uncaught TypeError: Cannot read property &#39;target&#39; of undefined

This error is being thrown in my second console.log statement.

What am I doing wrong? 

Also, I am considering making the `section` parameter optional. If so, is there an easy way to do this? It seems like it might not be possible if the event parameter needs to be last.


Passing an additional parameter with an onChange event

I&#39;m trying to embrace jQuery 100% with it&#39;s simple and elegant API but I&#39;ve run into an inconsistency between the API and straight-up HTML that I can&#39;t quite figure out.

I have an AJAX file uploader script (which functions correctly) that I want to run each time the file input value changes.  Here&#39;s my working code:

    &lt;input type=&quot;file&quot; size=&quot;45&quot; name=&quot;imageFile&quot; id=&quot;imageFile&quot; onchange=&quot;uploadFile()&quot;&gt;

When I convert the `onchange` event to a jQuery implementation:

    $(&#39;#imageFile&#39;).change(function(){ uploadFile(); });

the result isn&#39;t the same.  With the `onchange` attribute the `uploadFile()` function is called anytime the value is changed as is expected.  But with the jQuery API `.change()` event handler, the event only fires the first time a value is change.  Any value change after that is ignored.  This seems wrong to me but surely this can&#39;t be an oversight by jQuery, right?

Has anyone else encountered the same issue and do you have a workaround or solution to the problem other than what I&#39;ve described above?  

jQuery change method on input type=&quot;file&quot;

Currently the onChange event on my range inputs is firing at each step.

Is there a way to stop this event from firing until the user has let go of the slider?

I&#39;m using the range to create a search query. I want to be able to run the search every time the form is changed but issuing a search request at each step of the slider&#39;s movement is too much.

----------

Here&#39;s the code as it stands:

HTML:

    &lt;div id=&quot;page&quot;&gt;
        &lt;p&gt;Currently viewing page &lt;span&gt;1&lt;/span&gt;.&lt;/p&gt;
        &lt;input class=&quot;slider&quot; type=&quot;range&quot; min=&quot;1&quot; max=&quot;100&quot; step=&quot;1&quot; value=&quot;1&quot; name=&quot;page&quot; /&gt;
    &lt;/div&gt;

JavaScript:

    $(&quot;.slider&quot;).change(function() {
        $(&quot;#query&quot;).text($(&quot;form&quot;).serialize());
    });

Does that help?

onChange event for HTML5 range

I need to capture when a select box changes, should be simple!

    	$(&#39;#multiid&#39;).change(function(){
		alert(&#39;Change Happened&#39;);
	});

But it does not work, I suspected the problem is that the select box does not exist on document ready it is created only if needed, so I created it empty in HTML, populated it with code as a test but that didn&#39;t work either.

    function buildmulti(id,name,price) {
		// build action items for action bar
		var optlist = $(&#39;&lt;select&gt;&lt;/select&gt;&#39;).attr(&#39;id&#39;, &#39;multiid&#39;).attr(&#39;name&#39;, &#39;multiid&#39;);
		optlist.append(&#39;&lt;option value=&quot;0&quot;&gt;Select Size&lt;/option&gt;&#39;);
		$.each(option, function(index, val) {
			if(val.prodID *1  == id * 1) {
				v = val.ID;
				fprice = price * 1 + val.pricechange * 1;
				t = name + &#39; - &#39; + val.variation +  &#39; - &#39; + currency + (fprice).toFixed(2);
				optlist.append(&#39;&lt;option value=&quot;&#39; + v + &#39;&quot;&gt;&#39; + t + &#39;&lt;/option&gt;&#39;);
			}
		})
		$(&#39;#addbasket&#39;).append(optlist);
	};

it&#39;s probably another bracket out of place, but I can&#39;t find it!

Jquery select change not firing

I am quite new to React and after going through some tutorials, I was trying the below code of mine. 

I made one component, passed props to it from a store, on `componentWillMount` I make a new state for component. Rendering is fine till now.

Next I bound my `state` to value of an input box and I have `onChange` listener as well. Still, I can&#39;t change my values in the field.

Since, I am from Angular background, I am assuming binding input&#39;s value to state like below will automatically update the property `name` in `state` object. Am I wrong here?

        
    componentWillMount(){
        this.setState({
    	    updatable : false,
        	name : this.props.name,
        	status : this.props.status
        });
    }

    //relevant DOM from component&#39;s render function
    &lt;input className=&quot;form-control&quot; type=&quot;text&quot; value={this.state.name} id={&#39;todoName&#39; + this.props.id} onChange={this.onTodoChange.bind(this)}/&gt;
    
    onTodoChange(){
        console.log(this);
        //consoling &#39;this&#39; here, shows old values only.
        //not sure how and even if I need to update state here.
        // Do I need to pass new state to this function from DOM
        //TODO: send new data to store
    }

My `onTodoChange` function console the value of `this` which has same value of state as while initializing. How do I go about changing state by typing in input boxes, so that I can send them to the stores?

Why can&#39;t I change my input value in React even with the onChange listener

I have the following markup:

    &lt;select onchange=&quot;jsFunction()&quot;&gt;
        &lt;option value=&quot;1&quot;&gt;1&lt;/option&gt;
        &lt;option value=&quot;2&quot;&gt;2&lt;/option&gt;
        &lt;option value=&quot;3&quot;&gt;3&lt;/option&gt;
    &lt;/select&gt;


When a user pulls down the combobox and selects the same option that was previously selected (or doesn&#39;t change the selection at all), JavaScript doesn&#39;t regard it as an `onchange` event. So, the `jsFunction()` is not called. But I want the `jsFunction()` called even in this case. How can I achieve this?
 

How to fire a change event on a HTMLSelectElement if the new value is the same as the old?

I have a situation, where there are two fields. `field1` and `field2`. All I want
to do is empty `field2` when `field1` is changed and vice versa. So at the end only
one field has content on it.

    field1 = (EditText)findViewById(R.id.field1);
    field2 = (EditText)findViewById(R.id.field2);
    
    field1.addTextChangedListener(new TextWatcher() {
      
       public void afterTextChanged(Editable s) {}
     
       public void beforeTextChanged(CharSequence s, int start,
    	 int count, int after) {
       }
     
       public void onTextChanged(CharSequence s, int start,
    	 int before, int count) {
    	  field2.setText(&quot;&quot;);
       }
      });
    
    field2.addTextChangedListener(new TextWatcher() {
      
       public void afterTextChanged(Editable s) {}
     
       public void beforeTextChanged(CharSequence s, int start,
    	 int count, int after) {
       }
     
       public void onTextChanged(CharSequence s, int start,
    	 int before, int count) {
    	 field1.setText(&quot;&quot;);
       }
      });

It works fine if I attach `addTextChangedListener` to `field1` only, but when
I do it for both fields the app crashes. Obviously because they try to change
each other indefinitely. Once `field1` changes it clears `field2` at this moment
`field2` is changed so it will clear `field1` and so on...

Can someone suggest any solution?


All Onchange Solutions on Gang of Coders

Total of 20 Onchange Solutions