pdf-generator-service - DEPRECATED

There is no replacemrnt platform service provided at this time.

There are 2 common approaches to generating PDFs:

Use HTML to build a view, then turn that into a PDF. This is useful if the PDF you want to generate is a copy of a web page.
Generate a PDF without using HTML as an intermediary. A PDF is very different to a web page, especially if you expect a user to print the PDF. And the PDF should have its own design consideration. In some cases the end user of the PDF may be an entirely different user to the one creating the PDF. In the case of print and post forms for example, the PDF needs to mostly work for the person processing the form.

Performance issues with PNG image files

GhostScript is used to convert PDF to PDF/A format but but has a bug that results in slow conversion, poor rendering and large resulting files.
using gif format files instead of png avoids this issue

Endpoint URLs

POST /pdf-generator-service/pdf-generator/generate

Service Definitions

All requests use the HTTP POST method

PDF Generator Service

Functionality

* Generates a PDF based on the submitted html
* Generated PDF must be PDF/A 1 or PDF/A 2 compliant
* Generated PDF must match the HTML page from which it was generated

Request

* html-www-urlencoded-form with a required field 'html' that contains the html to be converted and an optional 'force-pdfa' boolean field to enforce PDF/A generation.
* post Content-Type: application/json {"html": "<html><title>Some Html</title></html>", "force-pdfa":"false"}

Response

* HTTP 200 OK with a generated and downloadable PDF
* HTTP 400 Bad Request for invalid/error scenarios

Run the application locally

Install wktohtml https://wkhtmltopdf.org/downloads.html version 0.12.3
Install Ghostscript https://ghostscript.com/
Check alias for ghostscript is ```gs
Check parameters in application.conf after "PdfGenerator Service config - use these values for local running only"

To run the application execute

sbt ~run 9852

The endpoints can then be accessed with the base url http://localhost:9852/pdf-generator-service/pdf-generator/generate

Tips on installing application on Ubuntu

This command will install ghostscript:

sudo apt-get install ghostscript

This command will install wkhtmltopdf:

sudo apt-get install wkhtmltopdf

We then need to add this symbolic link so that the service finds the program:

sudo ln -s /usr/bin/wkhtmltopdf /usr/local/bin

If you need to check the logs of the generator service, you may find it useful to use this command to remove the graphite warnings:

sm --start PDF_GENERATOR_SERVICE --appendArgs '{"PDF_GENERATOR_SERVICE":["-Dmicroservice.metrics.graphite.enabled=false"]}' -f

This command will bring up the logs of the pdf-generator-service:

sm --logs PDF_GENERATOR_SERVICE

GitHub API Token

You will need to generate a Personal Access Token (PAT) called GITHUB_API_TOKEN and store is a system variable by following the instructions on the GitHub page.

License

This code is open source software licensed under the Apache 2.0 License

hmrc/pdf-generator-service