[javascript] Programmatically trigger "select file" dialog box

I have a hidden file input element. Is it possible to trigger its select file dialog box from a button's click event?

I wrap the input[type=file] in a label tag, then style the label to your liking, and hide the input.

<label class="btn btn-default fileLabel" data-toggle="tooltip" data-placement="top" title="Upload">
    <input type="file">
    <span><i class="fa fa-upload"></i></span>
</label>

<style>
    .fileLabel input[type="file"] {
        position: fixed;
        top: -1000px;
    }
</style>

Purely CSS Solution.

The best solution, works in all browsers.. even on mobile.

<div class="btn" id="s_photo">Upload</div>

<input type="file" name="s_file" id="s_file" style="opacity: 0;">';

<!--jquery-->

<script>
    $("#s_photo").click(function() {
        $("#s_file").trigger("click");
    });
</script>

Hiding the input file type causes problems with browsers, opacity is the best solution because it isn't hiding, just not showing. :)

For those who want the same but are using React

openFileInput = () => {
    this.fileInput.click()
}

<a href="#" onClick={this.openFileInput}>
    <p>Carregue sua foto de perfil</p>
    <img src={img} />
</a>
<input style={{display:'none'}} ref={(input) => { this.fileInput = input; }} type="file"/>

I'm not sure how browsers handle clicks on type="file" elements (security concerns and all), but this should work:

$('input[type="file"]').click();

I've tested this JSFiddle in Chrome, Firefox and Opera and they all show the file browse dialog.

Make sure you are using binding to get component props in REACT

class FileUploader extends Component {
  constructor (props) {
    super(props);
    this.handleClick = this.handleClick.bind(this);
  }
   onChange=(e,props)=>{
    const files = e.target.files;
    const selectedFile = files[0];
    ProcessFileUpload(selectedFile,props.ProgressCallBack,props.ErrorCallBack,props.CompleatedCallBack,props.BaseURL,props.Location,props.FilesAllowed);
  }
   handleClick = () => {
    this.refs.fileUploader.click();
  }
  render()
  {
  return(
      <div>
        <button type="button" onClick={this.handleClick}>Select File</button>  
        <input type='file' onChange={(e)=>this.onChange(e,this.props)} ref="fileUploader" style={{display:"none"}} />
      </div>)
  }
}

Natively the only way is by creating an <input type="file"> element and then simulating a click, unfortunately.

There's a tiny plugin (shameless plug) which will take the pain away of having to do this all the time: file-dialog

fileDialog()
    .then(file => {
        const data = new FormData()
        data.append('file', file[0])
        data.append('imageName', 'flower')

        // Post to server
        fetch('/uploadImage', {
            method: 'POST',
            body: data
        })
    })

<div id="uploadButton">UPLOAD</div>
<form action="[FILE_HANDLER_URL]" style="display:none">
     <input id="myInput" type="file" />
</form>
<script>
  const uploadButton = document.getElementById('uploadButton');
  const myInput = document.getElementById('myInput');

  uploadButton.addEventListener('click', () => {
    myInput.click();
  });
</script>

Just for the record, there is an alternative solution that does not require javascript. It is a bit of a hack, exploiting the fact that clicking on a label sets the focus on the associated input.

You need a <label> with a proper for attribute (points to the input), optionnaly styled like a button (with bootstrap, use btn btn-default). When the user clicks the label, the dialog opens, example :

<!-- optionnal, to add a bit of style -->_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<!-- minimal setup -->_x000D_
<label for="exampleInput" class="btn btn-default">_x000D_
  Click me_x000D_
</label>_x000D_
<input type="file" id="exampleInput" style="display: none" />

There is no cross browser way of doing it, for security reasons. What people usually do is overlay the input file over something else and set it's visibility to hidden so it gets triggered on it's own. More info here.

Most answers here are lacking a useful information:

Yes, you can programmatically click the input element using jQuery/JavaScript, but only if you do it in an event handler belonging to an event THAT WAS STARTED BY THE USER!

So, for example, nothing will happen if you, the script, programmatically click the button in an ajax callback, but if you put the same line of code in an event handler that was raised by the user, it will work.

P.S. The debugger; keyword disrupts the browse window if it is before the programmatical click ...at least in chrome 33...

Using jQuery you can call click() to simulate a click.

This worked for me:

$('#fileInput').val('');