PhantomJS - Web Server Module Methods


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In this chapter, we will discuss regarding the various methods of the Web Server Module of PhantomJS.

close

The close method is used to close the webserver.

Syntax

Its syntax is as follows −

var server = require('webserver').create();
server.close();

Example

The following example shows how you can use the close method.

var webserver = require('webserver');
var server = webserver.create();
var service = server.listen(8080,function(request,response){
});

if(service) console.log("server started - http://localhost:" + server.port);
console.log(server.port);
server.close();
console.log(server.port);

The above program generates the following output.

server started - http://localhost:8080 
8080

Here, we have consoled server.port after closing the server. Hence, it will not respond, as the webserver is already closed.

listen

The server.listen method takes the port and callback function with two arguments, which are – Request Object and Response Object.

The Request Object contains the following properties −

  • Method − This defines the method GET /POST.

  • URL − This displays the requested URL.

  • httpVersion − This displays the actual http version.

  • Headers − This displays all the headers with key value pairs.

  • Post − Request body applicable only for the post method.

  • postRaw − If the Content-Type header is set to 'application/x-www-formurlencoded', the original content of the post will be stored in this extra property (postRaw) and then that post will be automatically updated with a URL-decoded version of the data.

The Response Object contains the following properties −

  • Headers − Has all the HTTP headers as key-value pairs. It should be set before calling write for the first time.

  • SetHeader − This sets a specific header.

  • Header (name) − It returns the value of the given header.

  • StatusCode − It sets the returned HTTP status code.

  • SetEncoding (encoding) − This is used to convert data given to write(). By default, data will be converted to UTF-8. Indicate "binary" if data is a binary string. Not required if data is a Buffer (e.g. from page.renderBuffer).

  • Write (data) − It sends data for the response body. Can be called multiple times.

  • WriteHead (statusCode, headers) − It sends a response header to the request. The status code is a 3-digit HTTP status code (e.g. 404). The last arguments and headers are the response headers.

  • Close − It closes the http connection.

  • CloseGracefully − It is similar to close(), but it makes sure the response headers have been sent first.

Syntax

Its syntax is as follows −

var server = require('webserver').create(); 
var listening = server.listen(8080, function (request, response) {} 

Example

Let us take an example to understand how the listen method works.

var page = require('webpage').create(); 
var server = require('webserver').create(); 
var port = 8080; 
var listening = server.listen(8080, function (request, response) { 
   console.log("GOT HTTP REQUEST"); 
   console.log(JSON.stringify(request, null, 4)); 
   
   // we set the headers here 
   response.statusCode = 200; 
   response.headers = {"Cache": "no-cache", "Content-Type": "text/html"};  
 
   // the headers above will now be sent implictly 
   // now we write the body 
   response.write("<html><head><title>Welcone to Phantomjs</title></head>"); 
   response.write("<body><p>Hello World</p></body></html>"); 
   response.close(); 
}); 

if (!listening) { 
   console.log("could not create web server listening on port " + port); 
   phantom.exit(); 
} 

var url = "http://localhost:" + port + "/foo/response.php"; 
console.log("sending request to :" +url); 
page.open(url, function (status) { 
   if (status !== 'success') { 
      console.log('page not opening'); 
   } else { 
      console.log("Getting response from the server:"); 
      console.log(page.content); 
   } 
   
   phantom.exit(); 
});

The above program generates the following output.

sending request to :http://localhost:8080/foo/response.php 
GOT HTTP REQUEST { 
   "headers": {
      "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8", 
      "Accept-Encoding": "gzip, deflate", 
      "Accept-Language": "en-IN,*", 
      "Connection": "Keep-Alive", 
      "Host": "localhost:8080", 
      "User-Agent": "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/538.1 
         (KHTML, like Gecko) PhantomJS/2.1.1 Safari/538.1" 
   }, 
   "httpVersion": "1.1", 
   "method": "GET", 
   "url": "/foo/response.php" 
} 
Getting response from the server: 
<html><head><title>Welcone to Phantomjs</title></head><body><p>Hello World</p></body>
</html> 


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