How to display a image selected from input type = file in reactJS

Question

I'm trying to display a image selected from my computer in my web app. I referred the following question which addresses the question i'm trying to fix.

How to display selected image without sending data to server?

I have my html part like this

 <div className="add_grp_image_div margin_bottom">
      <img src={img_upload} className="add_grp_image"/>
      <input type="file" className="filetype" id="group_image"/>
      <span className="small_font to_middle">Add group image</span>
      <img id="target"/>
 </div>

I want to display the selected image in

<img id="target"/>

How can i do this?

I referred FileReader docs as well.

https://developer.mozilla.org/en-US/docs/Web/API/FileReader

Answer 1

Hook version:

const [image, setImage] = useState(null)

const onImageChange = (event) => {
 if (event.target.files && event.target.files[0]) {
   setImage(URL.createObjectURL(event.target.files[0]));
 }
}

return (
  <div>
    <input type="file" onChange={onImageChange} className="filetype" />
    <img alt="preview image" src={image}/>
  </div>
)

Class version

render() {
   return (
     <div>
       <input type="file" onChange={onImageChange} className="filetype" />
       <img alt="preview image" src={this.state.image}/>
     <div/>
   )
}

onImageChange = (event) => {
 if (event.target.files && event.target.files[0]) {
   this.setState({image: URL.createObjectURL(event.target.files[0])});
 }
}

Another solution is to use FileReader

onImageChange = (event) => {
  if (event.target.files && event.target.files[0]) {
    let reader = new FileReader();
    reader.onload = (e) => {
      setImage(e.target.result);
    };
    reader.readAsDataURL(event.target.files[0]);
  }
}

Working demo: https://codesandbox.io/s/priceless-cerf-my900b