DocRaptor HTML TO PDF API

How to create a PDF with a Text-Based Watermark

"Draft" or "Confidential" watermarks are common on many PDFs. Fortunately, dynamically generated watermarked documents are easy to make with DocRaptor's HTML to PDF API!

Step 1: Make some Pages

To set up this example, we'll force the creation of three pages with the page-break-after CSS property. This simply adds a line-break after each <div>:

<div style="page-break-after: always;">Page 1</div>
<div style="page-break-after: always;">Page 2</div>
<div style="page-break-after: always;">Page 3</div>

For a document with actual content, you won't need these dummmy page breaks! We just wanted to show the watermark working across multiple pages.

Step 2: Define the Watermark

Let's make a really simple watermark:

<div id="watermark">PREVIEW</div>

Step 3: Add the Watermark

Here's where we leave regular CSS and HTML behind and showcase the power of DocRaptor's PDF engine:

#watermark {
  flow: static(watermarkflow);
}

@page {
   @prince-overlay {
      content: flow(watermarkflow)
   }
}

First, we use our custom flow CSS property to remove the #watermark block from the document flow. We put it into a separate flow that we've named watermarkflow.

When defining custom flows, the HTML for the flow must appear in your HTML code before where you want to use it. For watermarks (and headers/footers), it's best to put the HTML at the top of your HTML code (see our full examples below).

Next, we take newly defined flow and put it into the @prince-overlay page region. This particular page region is overlayed across the entire document page so it's perfect for a watermark. In this example, the same watermark is used on every page but we could also use another custom CSS propery, named pages, to create different watermarks on different pages or hide the watermarks on the intro pages.

Step 4: Style the Watermark

We added a really basic text watermark, so let's class it up with some more CSS styling:

#watermark {
  flow: static(watermarkflow);
  font-size: 120px;
  opacity: 0.5;
  transform: rotate(-30deg);
  text-align: center;
}

And that's all it takes! Just a few line of code to apply a custom PDF watermark. See below for complete PDF generation code examples in various languages.

This watermark code will not work on test documents (meaning it also won't work with our public API key). You must have a DocRaptor account to use watermarks.

Select Your Language

Using DocRaptor's API

Below are the basics of using DocRaptor's HTTP API. It can easily be used in any programming language, but if we don't have a native agent for your language, please let us know! That'll help us write the best examples and agents.

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

To make documents, send a POST request to this URL:

https://YOUR_API_KEY_HERE@api.docraptor.com/docs

Send JSON-encoded API parameters (you'll need to set an HTTP header for Content-Type as application/json). These are the only required parameters:

{
  "type": "pdf",
  "document_content": "Hello World!"
}

Generating the Document with cURL

Here's a completely functional code sample for this tutorial:

cat <<-'DOCUMENT_OPTIONS' > docraptor_parameters.json
  {
    "test": false,
    "document_type": "pdf",
    "document_content": "<div id=\"watermark\">PREVIEW</div><div style=\"page-break-after: always;\">Page 1</div><div style=\"page-break-after: always;\">Page 2</div><div style=\"page-break-after: always;\">Page 3</div><style>#watermark {flow: static(watermarkflow);font-size: 120px;opacity: 0.5;transform: rotate(-30deg);text-align: center;}@page {@prince-overlay {content: flow(watermarkflow)}}</style>"
  }
DOCUMENT_OPTIONS

curl https://YOUR_API_KEY_HERE@api.docraptor.com/docs \
  --fail --silent --show-error \
  --header "Content-Type:application/json" \
  --data @docraptor_parameters.json \
  > text-based-watermark.pdf

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Frameworks supported

  • .NET 4.0 or later
  • Windows Phone 7.1 (Mango)

Dependencies

Installing the .NET Agent

With Nuget:

nuget.exe install DocRaptor

With the Package Manager Console:

Install-Package DocRaptor

You can also download the DLL directly from GitHub.

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

using DocRaptor.Client;
using DocRaptor.Model;
using DocRaptor.Api;
using System;
using System.IO;

class DocRaptorExample
{
    static void Main(string[] args)
    {
        DocApi docraptor = new DocApi();
        // this key works in test mode!
        docraptor.Configuration.Username = "YOUR_API_KEY_HERE";

        try
        {
            Doc doc = new Doc(
                name: "text-based-watermark",
                test: false, // test documents are free but watermarked
                documentType: Doc.DocumentTypeEnum.Pdf,
                documentContent: System.IO.File.ReadAllText(@"text-based-watermark-content.html") 
                // documentUrl: "https://docraptor.com/examples/invoice.html", 
                // javascript: true, 
                // princeOptions: new PrinceOptions(
                //     media: "print", // @media 'screen' or 'print' CSS
                //     baseurl: "https://yoursite.com" // the base URL for any relative URLs
                // )
            );

            byte[] document = docraptor.CreateDoc(doc);
            File.WriteAllBytes("text-based-watermark.pdf", document);
            Console.WriteLine("Successfully created text-based-watermark.pdf!");
        } catch (DocRaptor.Client.ApiException error) {
            Console.Write(error.ErrorContent);
        }
    }
}

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Install the Java Agent

Add the com.docraptor package to your project. For example, with Maven you'd add the DocRaptor package to your pom.xml:

<dependency>
  <groupId>com.docraptor</groupId>
  <artifactId>docraptor</artifactId>
  <version>3.0.0</version>
</dependency>

And then install it:

mvn install com.docraptor

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

import com.docraptor.*;
import java.io.*;
import java.net.*;
import java.nio.file.*;

public class DocRaptorExample {

  public static void main(String[] args) throws Exception {
    DocApi docraptor = new DocApi();
    ApiClient client = docraptor.getApiClient();
    client.setUsername("YOUR_API_KEY_HERE"); // this key works in test mode!

    try {
      Doc doc = new Doc();
      doc.setTest(false); // test documents are free but watermarked
      doc.setDocumentType(Doc.DocumentTypeEnum.PDF);

      doc.setDocumentContent(new String(Files.readAllBytes(Paths.get("text-based-watermark-content.html"))));

      // doc.setDocumentUrl("https://docraptor.com/examples/invoice.html");
      // doc.setJavascript(true);
      // PrinceOptions princeOptions = new PrinceOptions();
      // princeOptions.setMedia("print"); // @media 'screen' or 'print' CSS
      // princeOptions.setBaseurl("https://yoursite.com"); // the base URL for any relative URLs
      // doc.setPrinceOptions(princeOptions);

      byte[] document = docraptor.createDoc(doc);

      // createDoc() returns a binary string
      FileOutputStream file = new FileOutputStream(
        "text-based-watermark.pdf"
      );
      file.write(document);
      file.close();
      System.out.println("Successfully created text-based-watermark.pdf!");
    } catch (ApiException error) {
      System.err.println(error);
      System.err.println(error.getCode());
      System.err.println(error.getMessage());
      System.err.println(error.getResponseBody());
    }
  }
}

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

The DocRaptor JavaScript Library

The DocRaptor JavaScript library makes it easy to create PDFs with JavaScript. The library does not require jQuery, but you can use jQuery to define your document content. When a PDF is requested, the library constructs a hidden form and submits it to the DocRaptor API. The form is necessary to trigger the browser download window.

This library exposes your API key in your website source code. This code should never be used in a publicly-accessible location, instead try using our referrer-based API or a server-side agent such as PHP or Ruby.

JavaScript Example

<html>
  <head>
    <script src="https://docraptor.com/docraptor-1.0.0.js"></script>
    <script>
      var downloadDocumentFrom = function(selector) {
        // this key works in test mode!
        DocRaptor.createAndDownloadDoc("YOUR_API_KEY_HERE", {
          name: "text-based-watermark",
          test: false, // test documents are free but watermarked
          document_type: "pdf",
          document_content: document.querySelector(selector).innerHTML
          // document_url: "https://docraptor.com/examples/invoice.html",
          // javascript: true,
          // prince_options: {
          //   media: "print", // @media 'screen' or 'print' CSS
          //   baseurl: "https://yoursite.com", // the base URL for any relative URLs
          // }
        });
      };
    </script>
    <style>
      @media print {
        #download-button {
          display: none;
        }
      }
    </style>
  </head>
  <body>
    <div id="watermark">PREVIEW</div>
    <div style="page-break-after: always;">Page 1</div>
    <div style="page-break-after: always;">Page 2</div>
    <div style="page-break-after: always;">Page 3</div>

    <style>
      #watermark {
        flow: static(watermarkflow);
        font-size: 120px;
        opacity: 0.5;
        transform: rotate(-30deg);
        text-align: center;
      }

      @page {
        @prince-overlay {
          content: flow(watermarkflow);
        }
      }
    </style>
    <button id="download-button" type="button" onclick="downloadDocumentFrom('html')">Download Document</button>
  </body>
</html>

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

DocRaptor & Node.js

The best way to use DocRaptor with Node.js is directly through our HTTP API. In this example, we'll use the axios module, but you can obviously use any HTTP client you'd like.

Install the Axios Module

npm install axios

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

const axios = require("axios");
const fs = require("fs");

const document_content = `
  <div id="watermark">PREVIEW</div>
  <div style="page-break-after: always;">Page 1</div>
  <div style="page-break-after: always;">Page 2</div>
  <div style="page-break-after: always;">Page 3</div>

  <style>
    #watermark {
      flow: static(watermarkflow);
      font-size: 120px;
      opacity: 0.5;
      transform: rotate(-30deg);
      text-align: center;
    }

    @page {
       @prince-overlay {
          content: flow(watermarkflow)
       }
    }
  </style>
`;

config = {
  url: "https://api.docraptor.com/docs",
  method: "post",
  responseType: "arraybuffer", //IMPORTANT! Required to fetch the binary PDF
  headers: {
    "Content-Type": "application/json"
  },
  data: {
    user_credentials: "YOUR_API_KEY_HERE", // this key works in test mode!
    doc: {
      test: false, // test documents are free but watermarked
      document_type: "pdf",
      document_content: document_content
      // document_url: "https://docraptor.com/examples/invoice.html",
      // javascript: true,
      // prince_options: {
      //   media: "print", // @media 'screen' or 'print' CSS
      //   baseurl: "https://yoursite.com", // the base URL for any relative URLs
      //   }
    }
  }
};

axios(config)
  .then(function(response) {
    fs.writeFile(
      "text-based-watermark.pdf",
      response.data,
      "binary",
      function(writeErr) {
        if (writeErr) throw writeErr;
        console.log("Saved text-based-watermark.pdf!");
      }
    );
  })
  .catch(function(error) {
    // DocRaptor error messages are contained in the response body
    // Since the response is binary encoded, let's decode
    var decoder = new TextDecoder("utf-8");
    console.log(decoder.decode(error.response.data));
  });

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Installing the PHP Agent

composer require docraptor/docraptor

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

<?php

require_once __DIR__ . "/vendor/autoload.php";

$docraptor = new DocRaptor\DocApi();
# this key works in test mode!
$docraptor->getConfig()->setUsername("YOUR_API_KEY_HERE");

$document_content = <<<DOCUMENT_CONTENT
  <div id="watermark">PREVIEW</div>
  <div style="page-break-after: always;">Page 1</div>
  <div style="page-break-after: always;">Page 2</div>
  <div style="page-break-after: always;">Page 3</div>

  <style>
    #watermark {
      flow: static(watermarkflow);
      font-size: 120px;
      opacity: 0.5;
      transform: rotate(-30deg);
      text-align: center;
    }

    @page {
       @prince-overlay {
          content: flow(watermarkflow)
       }
    }
  </style>
DOCUMENT_CONTENT;

try {
    $doc = new DocRaptor\Doc();
    $doc->setTest(false); # test documents are free but watermarked
    $doc->setDocumentType("pdf");
    $doc->setDocumentContent($document_content);
    # $doc->setDocumentUrl("https://docraptor.com/examples/invoice.html");
    # $doc->setJavascript(true);
    # $prince_options = new DocRaptor\PrinceOptions();
    # $doc->setPrinceOptions($prince_options);
    # $prince_options->setMedia("print"); # @media 'screen' or 'print' CSS
    # $prince_options->setBaseurl("https://yoursite.com"); # the base URL for any relative URLs

    $response = $docraptor->createDoc($doc);

    # createDoc() returns a binary string
    file_put_contents("text-based-watermark.pdf", $response);
    echo "Successfully created text-based-watermark.pdf!";
} catch (DocRaptor\ApiException $error) {
    echo $error . "\n";
    echo $error->getMessage() . "\n";
    echo $error->getCode() . "\n";
    echo $error->getResponseBody() . "\n";
}

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Installing the Python Agent

pip install --upgrade docraptor

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

import docraptor

doc_api = docraptor.DocApi()
# this key works in test mode!
doc_api.api_client.configuration.username = 'YOUR_API_KEY_HERE'

document_content = r"""
    <div id="watermark">PREVIEW</div>
    <div style="page-break-after: always;">Page 1</div>
    <div style="page-break-after: always;">Page 2</div>
    <div style="page-break-after: always;">Page 3</div>

    <style>
      #watermark {
        flow: static(watermarkflow);
        font-size: 120px;
        opacity: 0.5;
        transform: rotate(-30deg);
        text-align: center;
      }

      @page {
         @prince-overlay {
            content: flow(watermarkflow)
         }
      }
    </style>
"""

try:
    response = doc_api.create_doc({
        'test': False,  # test documents are free but watermarked
        'document_type': 'pdf',
        'document_content': document_content,
        # 'document_url': 'https://docraptor.com/examples/invoice.html',
        # 'javascript': True,
        # 'prince_options': # {
        #    'media': 'print', # @media 'screen' or 'print' CSS
        #    'baseurl': 'https://yoursite.com', # the base URL for any relative URLs
        # },
    })

    # create_doc() returns a binary string
    with open('text-based-watermark.pdf', 'w+b') as f:
        binary_formatted_response = bytearray(response)
        f.write(binary_formatted_response)
        f.close()
    print('Successfully created text-based-watermark.pdf!')
except docraptor.rest.ApiException as error:
    print(error.status)
    print(error.reason)
    print(error.body)

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Installing the Ruby Agent

Add or require the docraptor gem to your project or script.

Generating the Document

The API key shown here, YOUR_API_KEY_HERE, actually works! Use it for testing without creating an account. The only requirement is test mode must be used (test parameter set to true).

require "docraptor"

DocRaptor.configure do |config|
  config.username = "YOUR_API_KEY_HERE" # this key works in test mode!
end

docraptor = DocRaptor::DocApi.new

document_content = <<~'DOCUMENT_CONTENT'
  <div id="watermark">PREVIEW</div>
  <div style="page-break-after: always;">Page 1</div>
  <div style="page-break-after: always;">Page 2</div>
  <div style="page-break-after: always;">Page 3</div>

  <style>
    #watermark {
      flow: static(watermarkflow);
      font-size: 120px;
      opacity: 0.5;
      transform: rotate(-30deg);
      text-align: center;
    }

    @page {
       @prince-overlay {
          content: flow(watermarkflow)
       }
    }
  </style>
DOCUMENT_CONTENT

begin
  response = docraptor.create_doc(
    test: false, # test documents are free but watermarked
    document_type: "pdf",
    document_content: document_content,
    # document_url: "https://docraptor.com/examples/invoice.html",
    # javascript: true,
    # prince_options: {
    #   media: "print", # @media 'screen' or 'print' CSS
    #   baseurl: "https://yoursite.com", # the base URL for any relative URLs
    # }
  )

  # create_doc() returns a binary string
  File.write("text-based-watermark.pdf", response, mode: "wb")
  puts "Successfully created text-based-watermark.pdf!"
rescue DocRaptor::ApiError => error
  puts "#{error.class}: #{error.message}"
  puts error.code
  puts error.response_body
  puts error.backtrace[0..3].join("\n")
end

Downloads

Here are all the files you need to follow this tutorial:

Related Tutorials & Documentation

See the complete PDF tutorial list or review the documentation for additional info, such as generating asynchronous documents.

Ready to get started? Try DocRaptor for free with unlimited test documents.