How to View an Uploaded File in React JS?

You can view an uploaded file in React JS by using the FileReader API. Here's a breakdown of the process:

1. Obtain the File Object

• When a user uploads a file, you get a File object. This object contains information about the uploaded file, including its name, size, and type.

2. Create a FileReader Object

• Create a new FileReader object.

3. Use the FileReader API

• The FileReader API provides methods for reading the contents of a file. The most common method is readAsDataURL(). This method reads the file as a data URL, which is a base64 encoded string that represents the file's content.

4. Handle the Result

• The FileReader object has an onload event that fires when the file has been read successfully. This event provides the result property, which contains the data URL.

Example:

function handleFileChange(event) {
  const file = event.target.files[0];
  const reader = new FileReader();

  reader.onload = (e) => {
    const dataUrl = e.target.result;
    // You can now use the dataUrl to display the image in an <img> tag.
    // For example:
    document.getElementById('imagePreview').src = dataUrl;
  };

  reader.readAsDataURL(file);
}

Practical Considerations:

• Image Preview: You can use the data URL to display an image preview in an <img> tag.
• File Type: You can use the file.type property to determine the file type and display it accordingly.
• Error Handling: You should handle potential errors using the onerror event of the FileReader object.