React js check if input file is empty
React js check if input file is empty:To check if an input file is empty in Reactjs, you can utilize the FileReader API. First, access the file input element using its reference or ID. Then, create a new instance of the FileReader class and use its
readAsText() method to read the file. Finally, add an event listener for the load event and check the file's length property. If it's zero, the file is empty; otherwise, it contains content.
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How can I use Reactjs to check if an input file is empty?
This Reactjs code snippet demonstrates how to check if an input file is empty. Upon selecting a file, the handleFileChange function is triggered. It checks if a file is selected and then reads its contents using FileReader. If the file content length is greater than zero, indicating a non-empty file, the setFile function is called with the selected file.
Otherwise, if the file is empty or no file is selected, the setFile function is called with null. The handleSubmit function can be used for further processing or form submission and is triggered by a submit button, which is disabled if no file is selected.
React js check if input file is empty Example
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xxxxxxxxxx <script type="text/babel"> const { useState } = React; const App = () => { const [file, setFile] = useState(null); const handleFileChange = (event) => { const selectedFile = event.target.files[0]; if (selectedFile) { const reader = new FileReader(); reader.onload = () => { const fileContent = reader.result; if (fileContent.length > 0) { // File is not empty setFile(selectedFile); } else { // File is empty setFile(null); } }; reader.readAsText(selectedFile); } else { // No file selected setFile(null); } }; const handleSubmit = (event) => { event.preventDefault(); // Perform the form submission or further processing here }; return ( <div className="container"> <h3>React js check if input file is empty </h3> <input type="file" onChange={handleFileChange} /> <button type="submit" onClick={handleSubmit} disabled={!file}> Submit </button> </div> ); }; ReactDOM.render(<App />, document.getElementById("app")); </script>Output of React js check if input file is empty
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