The httpServerResponse.writableFinished is an inbuilt application programming interface of class ServerResponse within http module which is used to check if all the data has been flushed or not.
Syntax:
response.writableFinished
Parameters: This property does not accept any arguments as a parameter.
Return Value: This property returns true if and only if all the data has been flushed or not.
Example 1: Filename: index.js
// Node.js program to demonstrate the
// response.writableFinished APi
// Importing http module
const http = require('http');
// Setting up PORT
const PORT = process.env.PORT || 3000;
// Creating http Server
const httpServer = http.createServer(
function (request, response) {
// Checking all the data has been flushed
// or not by using writableFinished API
const value = response.writableFinished;
// Display the result
// by using end() api
response.end("Data has been flushed : "
+ value, 'utf8', () => {
console.log("displaying the result...");
// Closing the server
httpServer.close(() => {
console.log("server is closed")
})
});
});
// Listening to http Server
httpServer.listen(PORT, () => {
console.log("Server is running at port 3000...");
});
Run the index.js file using the below command:
node index.js
Console output:
Server is running at port 3000... displaying the result... displaying the result... server is closed server is closed
Browser Output: Paste the localhost address http://localhost:3000/. In the search bar of the browser.
Data has been flushed : false
Example 2: Filename: index.js
// Node.js program to demonstrate the
// response.writableFinished APi
// Importing http module
const http = require('http');
// Request and response handler
const http2Handlers = (request, response) => {
// checking all the data has been flushed or not
// by using writableFinished API
const value = response.writableFinished;
// display result
// by using end() api
response.end("Data has been flushed : "
+ value, 'utf8', () => {
console.log("displaying the result...");
const value1 = response.writableFinished;
console.log("Data has been flushed " + value1);
httpServer.close(() => {
console.log("server is closed")
})
});
};
// Creating http Server
const httpServer = http.createServer(
http2Handlers).listen(3000, () => {
console.log("Server is running at port 3000...");
});
Run the index.js file using the below command:
node index.js
Console Output:
Server is running at port 3000... displaying the result... Data has been flushed true
Browser Output: Paste the localhost address http://localhost:3000/. In the search bar of the browser.
Data has been flushed : false
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http.html#http_response_writablefinished