PhantomJS - Screen Capture


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PhantomJS is very helpful in taking a screenshot of a webpage and converting a webpage into a PDF. We have given here a simple example to demonstrate how it works.

Example

var page = require('webpage').create();
page.open('http://phantom.org/',function(status){
   page.render('phantom.png');
   phantom.exit();
});

Execute the above program and the output will be saved as phantom.png.

Optimal Solution

Convert Webpages into PDFs

PhantomJS also helps to convert webpages into PDFs with header and footer added to it. Take a look at the following example to understand how it works.

var wpage = require('webpage').create(); 
var url = "https://en.wikipedia.org/wiki/Main_Page"; 
var output = "test.pdf"; 

wpage.paperSize = { 
   width: screen.width+'px', 
   height: '1500px', 
   
   margin: {
      'top':'50px', 
      'left':'50px', 
      'rigtht':'50px' 
   }, 
   orientation:'portrait', 
   header: { 
      height: "1cm", 
      contents: phantom.callback(function(pageNumber, nPages) { 
         return "<h5>Header <b>" + pageNumber + " / " + nPages + "</b></h5>"; 
      }) 
   }, 
   footer: { 
      height: "1cm", 
      contents: phantom.callback(function(pageNumber, nPages) {   
         return "<h5>Footer <b>" + pageNumber + " / " + nPages + "</b></h5>"; 
      }) 
   } 
} 
wpage.open(url, function (status) { 
   if (status !== 'success') { 
      console.log('Page is not opening'); 
      phantom.exit(); 
   } else { 
      wpage.render(output); 
      phantom.exit();     
   } 
});

The above program generates the following output.

The above will convert the page into pdf and will be saved in test.pdf

Convert a Canvas to an Image

Phantomjs can easily convert a Canvas to an Image. Take a look at the following example to understand how it works.

var page = require('webpage').create(); 
page.content = '<html><body><canvas id="surface" width="400" height="400"></canvas></body></html>'; 

page.evaluate(function() {
   var context,e1; 
   el = document.getElementById('surface'); 
   
   context = el.getContext('2d'); 
   context.font = "30px Comic Sans MS"; 
   context.fillStyle = "red"; 
   context.textAlign = "center"; 
   context.fillText("Welcome to PhantomJS ", 200, 200); 
   
   document.body.style.backgroundColor = 'white'; 
   document.body.style.margin = '0px'; 
}); 
page.render('canvas.png'); 
phantom.exit(); 

The above program generates the following output.

Welcome Phantomjs

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