README

PDFGenerator allows you to easily generate PDF documents or PNG screenshots of any webpage using PHP.

In the past we have used PhantomJS, wkhtmltopdf and TCPDF to generate PDF's from a given URL or HTML. However, these libraries are no longer actively developed or maintained and lack support for newer features in HTML and CSS. Google Chrome has a built in feature to take a screenshot of a webpage as PDF or PNG format with better support for new features.

Using Amazon Lambda and Amazon API Gateway you can minimize running costs, have scalable performance and flexible security controls. Lambda is used to run a headless Chrome as an on-demand service to take screenshots from any website or submitted HTML content without having to set up a server. You can configure security controls on the API Gateway like API keys, rate limiting, and quota to protect your screenshot service against third parties or inappropriate use.

Puppeteer is used to communicate with Chrome to load content and take screenshots programmatically.

Requirements

To deploy Chrome on Amazon Lambda you will need:

An Amazon AWS account to deploy the Lambda function
Node.js installed on your local machine
Serverless installed on your local machine

To use this library in PHP:

Composer
PHP 7+

Deploying Chrome on Amazon Lambda

Go to the official Node.js website, download and follow the installation instructions to install Node.js on your local machine.
Install the Serverless Framework via npm which was already installed when you installed Node.js.
Open up a terminal and run the following command to install Serverless:

npm install -g serverless

Next, you'll have to set up your credentials so that Serverless is able to connect to your Amazon AWS account to deploy the Lambda function and API Gateway. The easiest way is to create a new IAM user and attach a custom JSON policy to limit the Serverless Framework's access to your AWS account. This way you don't have to sign up for an account on https://serverless.com either.
To limit the Serverless Framework’s access your AWS account, follow these steps to create an IAM User and attach a custom JSON file policy to your new IAM User. This IAM User will have its own set of AWS Access Keys.

Login to your AWS Account and go to the Identity & Access Management (IAM) page.
Click on Users and then Add user. Enter a name in the first field to remind you this User is related to the Service you are deploying with the Serverless Framework, like serverless-servicename-agent1. Enable Programmatic access by clicking the checkbox. Click Next to go through to the Permissions page. Click on Create policy. Select the JSON tab, and add a JSON file. You can use this gist as a guide.
When you are finished, select Review policy. You can assign this policy a Name and Description, then choose Create Policy. Check to make sure everything looks good and click Create user. Later, you can create different IAM Users for different apps and different stages of those apps. That is, if you don't use separate AWS accounts for stages/apps, which is most common.
View and copy the API Key & Secret and replace <your-key-here> and <your-secret-key-here> in the command below and run the command:

serverless config credentials --provider aws --key <your-key-here> --secret <your-secret-key-here>

Navigate to the directory screenshot-service in this repository in your terminal window and install the required packages by running:

npm install

Open screenshot-service/serverless.yml and change the region on line 10 to the region you wish to deploy to on Amazon AWS as well as the corresponding reference to the required Lambda layer on line 27. See https://github.com/shelfio/chrome-aws-lambda-layer and [https://docs.aws.amazon.com/general/latest/gr/rande.html#regional-endpoints]{https://docs.aws.amazon.com/general/latest/gr/rande.html#regional-endpoints} for more information about the available regions and corresponding references for the Lambda layer.

  region: eu-west-3
  ...
    layers: # reference to the already existing layer with Chrome
      - arn:aws:lambda:eu-west-3:764866452798:layer:chrome-aws-lambda:31

Next, deploy the screenshot service to Amazon AWS:

serverless deploy --stage production

In the output of the command about you can find the endpoints for the GET and POST request.

If you haven't configured any API keys yet in the API Gateway for the screenshot service, you can simply copy the endpoint URL of the GET request, append ?filename=screenshot.png&url=[URL of your website] to the endpoint URL and open it in your browser.

Note that you have to set API Key Required to false for the /capture - GET -Method Request in the API to test this without API Keys:

Go to Amazon API Gateway
Open the API for the screenshot service
Click on GET under /capture in the Resources panel
Click on Method Request
Click on the pencil icon next to API Key Required, change the setting from true to false, and click the check mark icon to save the setting.
Click on the Actions button, and choose Deploy API from the menu to redeploy the API to test the GET-request without API Keys.

Make sure to set API Key Required to true after you have verified that the screenshot service works in order to prevent unauthorized use or access.

For example: https://##########.execute-api.eu-west-3.amazonaws.com/dev/capture?filename=screenshot.png&url=https://www.google.com/finance/quote/TSLA:NASDAQ?hl=en returns a screenshot of the Tesla stock on Google Finance:

Securing your screenshot service

To protect the screenshot service against unauthorized use or access you can set up API Keys for the API Gateway. If you do not set up API Keys for the screenshot service other people may be able to use your installation to create screenshots which will add to your bill. It is important that you secure your API Gateway.

Make sure to redeploy the API for the API Key requirement to take effect!

See https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-setup-api-key-with-console.html on how to set up API Keys.

Installation of this library

composer require viavario\pdfgenerator

Usage

<?php
include_once __DIR__.'/vendor/autoload.php';

use viavario\pdfgenerator\PDFGenerator;

// This is invoke URL of the API Gateway or the endpoint returned by the
// serverless deploy command without `capture` at the end
$endpoint = 'https://##########.execute-api.eu-west-3.amazonaws.com/dev/';
$apiKey = '<your-api-key>'; // Your API Key configured in the API Gateway
$filename = 'screenshot.pdf'; // Change to screenshot.png to get a PNG image

$generator = new PDFGenerator($endpoint, $apiKey);
$generator->setURL('https://google.com')
    ->setFilename($filename)
    ->setMargins('1.5cm')
    ->setFormat('A4')
    // The screenshot service automatically increases the height of the viewport
    // to take a full page screenshot
    ->setViewportSize(1920, 1080)
    ->setOrientation(PDFGenerator::ORIENTATION_PORTRAIT);

try {
    $tempfile = $generator->generate();
    // Change the Content-Type to image/png if you changed the extension of the
    // filename to .png
    header('Content-Type: application/pdf');
    echo $tempfile;
}
catch (\Exception $e) {
    echo $e->getMessage();
}

Methods

Name	Description
__construct	Class constructor.
displayHeaderFooter	Display the footer and header template.
generate	Generate a screenshot.
omitBackground	Hides default white background and allows capturing screenshots with transparency. Defaults to false.
preferCSSPageSize	Give any CSS @page size declared in the page priority over what is declared in width and height or format options. Defaults to false, which will scale the content to fit the paper size.
printBackground	Set to true to print backgrounds.
setContent	Sets the content.
setFilename	Sets the filename.
setFooterTemplate	Sets the Footer template.
setFormat	Sets the format of the page.
setHeaderTemplate	Sets the Header template.
setHttpAuthentication	Sets the HTTPAuthentication username and password.
setMargins	Sets the margins for the page.
setOrientation	Set the page orientation.
setURL	Set the URL.
setViewportSize	Sets the viewport height and viewport width.

PDFGenerator::__construct

Description

public __construct (string $endpoint, string $apiKey)

Class constructor.

Parameters

(string) $endpoint : The endpoint URL
(string) $apiKey : The API key for the AWS Lambda function

Return Values

void

PDFGenerator::displayHeaderFooter

Description

public displayHeaderFooter (bool $displayHeaderFooter)

Display the footer and header template.

Parameters

(bool) $displayHeaderFooter : set to true to display the header and footer in the PDF document

Return Values

PDFGenerator

PDFGenerator::generate

Description

public generate (string $filename)

Generate a screenshot.

Parameters

(string) $filename : The filename to write to (defaults to null which will cause the method to return binary data)

Return Values

mixed

If no filename is specified, then the generated file is returned as binary data.
If a filename is specified, then true is returned when the file was written
successfully, or false otherwise.

PDFGenerator::omitBackground

Description

public omitBackground (bool $omitBackground)

Hides default white background and allows capturing screenshots with transparency. Defaults to false.

Parameters

(bool) $omitBackground : set to true to omit white backgrounds

Return Values

PDFGenerator

PDFGenerator::preferCSSPageSize

Description

public preferCSSPageSize (bool $preferCSSPageSize)

Give any CSS @page size declared in the page priority over what is declared in width and height or format options. Defaults to false, which will scale the content to fit the paper size.

Parameters

(bool) $preferCSSPageSize : set to true to enqble CSS page size

Return Values

PDFGenerator

PDFGenerator::printBackground

Description

public printBackground (bool $printBackground)

Set to true to print backgrounds.

Parameters

(bool) $printBackground : Set to true to print backgrounds

Return Values

PDFGenerator

PDFGenerator::setContent

Description

public setContent (string $content)

Sets the content.

Parameters

(string) $content : the HTML content to take a screenshot of

Return Values

PDFGenerator

PDFGenerator::setFilename

Description

public setFilename (string $filename)

Sets the filename.

Parameters

(string) $filename : Set the filename for the output. Only extensions .pdf and .png are allowed.

Return Values

PDFGenerator

PDFGenerator::setFooterTemplate

Description

public setFooterTemplate (string $html)

Sets the Footer template.

Should be valid HTML markup with following classes used to inject printing values into them:

date formatted print date
title document title
url document location
pageNumber current page number
totalPages total pages in the document

Parameters

(string) $html : HTML Markup

Return Values

PDFGenerator

PDFGenerator::setFormat

Description

public setFormat (void)

Sets the format of the page.

The format options are:

Letter: 8.5in x 11in
Legal: 8.5in x 14in
Tabloid: 11in x 17in
Ledger: 17in x 11in
A0: 33.1in x 46.8in
A1: 23.4in x 33.1in
A2: 16.54in x 23.4in
A3: 11.7in x 16.54in
A4: 8.27in x 11.7in
A5: 5.83in x 8.27in
A6: 4.13in x 5.83in

Parameters

This function has no parameters.

Return Values

PDFGenerator

PDFGenerator::setHeaderTemplate

Description

public setHeaderTemplate (string $html)

Sets the Header template.

Should be valid HTML markup with following classes used to inject printing values into them:

date formatted print date
title document title
url document location
pageNumber current page number
totalPages total pages in the document

Parameters

(string) $html : HTML Markup

Return Values

PDFGenerator

PDFGenerator::setHttpAuthentication

Description

public setHttpAuthentication (void)

Sets the HTTPAuthentication username and password.

Parameters

This function has no parameters.

Return Values

PDFGenerator

PDFGenerator::setMargins

Description

public setMargins (string $margins, string $right, string $bottom, string $left)

Sets the margins for the page.

Parameters

(string) $margins : Top margin, or all margins
(string) $right : Right margin
(string) $bottom : bottom margin
(string) $left : Left margin

Return Values

PDFGenerator

return this instance

PDFGenerator::setOrientation

Description

public setOrientation (string $orientation)

Set the page orientation.

Parameters

(string) $orientation : PDFGenerator::ORIENTATION_LANDSCAPE or PDFGenerator::ORIENTATION_PORTRAIT

Return Values

PDFGenerator

PDFGenerator::setURL

Description

public setURL (string $url)

Set the URL.

Parameters

(string) $url : the URL of the page to take a screenshot of

Return Values

PDFGenerator

PDFGenerator::setViewportSize

Description

public setViewportSize (void)

Sets the viewport height and viewport width.

Parameters

This function has no parameters.

Return Values

PDFGenerator

viavario / pdfgenerator

Maintainers

Details

README

Requirements

Deploying Chrome on Amazon Lambda

Securing your screenshot service

Installation of this library

Usage

Methods

PDFGenerator::__construct

PDFGenerator::displayHeaderFooter

PDFGenerator::generate

PDFGenerator::omitBackground

PDFGenerator::preferCSSPageSize

PDFGenerator::printBackground

PDFGenerator::setContent

PDFGenerator::setFilename

PDFGenerator::setFooterTemplate

PDFGenerator::setFormat

PDFGenerator::setHeaderTemplate

PDFGenerator::setHttpAuthentication

PDFGenerator::setMargins

PDFGenerator::setOrientation

PDFGenerator::setURL

PDFGenerator::setViewportSize