Plantuml website diagram scraper

"I'll play until they have to scrape me off the stage." ~ James Young

Scrape all PlantUML diagrams from the PlantUML website.

Introduction

This repository contains code with the soul purpose of extracting all PlantUML diagrams from the PlantUML website that can be used as test material for PlantUML Themes^[1].

TL;DR

Use the already scraped diagrams in build/diagrams/

To generate them again:

• Run the project code
• See the project output

Run the project code

git clone https://github.com/potherca-blog/plantuml-website-diagram-scraper.git
cd plantuml-website-diagram-scraper/
composer install
bash ./cli/run.sh ./build/

See the project output

tree -vFL 2 --dirsfirst

.
├── build/
│   ├── diagrams/               <─ 5. The ouput diagrams     ─> Used in PlantUML Themes
│   ├── plantuml-images/        <─ 2. The downloaded images
│   ├── plantuml.com/           <─ 1. The downloaded website
│   └── diagrams.txt            <─ 3. The extracted diagrams
├── cli/
│   └── run.sh
├── web/                        <─ 4. Compare images with diagrams
│   ├── plantuml-diagrams.php
│   └── plantuml-images.php
└── README.md                   <─ 0. You are here

6 directories, 5 files

Installation

To install this project, download the source code and install the dependencies:

git clone https://github.com/potherca-blog/plantuml-website-diagram-scraper.git
cd plantuml-website-diagram-scraper/
composer install

Usage

The extraction is done taking the following steps:

1. Download the PlantUML website (so we only hit their servers once per page).
2. Dowload the images used in the website
3. Grab the diagrams from the local HTML pages
4. Compare the result of the diagrams with that of the dowloaded images
5. Output diagrams to separate files

The resulting diagrams can then be used as source for PlantUML Themes.

All of these steps can be executed by running the cli/run.sh shell script.

Inner workings

1. Download the PlantUML website

The PlantUML website is downloaded using wget:

# src/download_pages.sh
wget                            \
    --convert-links             \
    --directory-prefix='build/' \
    --domains 'plantuml.com'    \
    --force-directories         \
    --html-extension            \
    --no-clobber                \
    --no-parent                 \
    --no-verbose                \
    --page-requisites           \
    --recursive                 \
    --wait=0.05                 \
    'plantuml.com'

2. Dowload the images

The images are grabbed from the HTML pages from local PlantUML website and downloaded using parallel and wget:

# src/download_images.sh
find 'build/plantuml.com' -name '*.html' \
    -exec grep -R -a -P -o 'http://s.plantuml.com/img[pw]/[^"]+\.png' {} \+ \
    | cut -d':' -f2- \
    | parallel --gnu "wget --no-verbose --directory-prefix=build/plantuml-images {}"

3. Grab the diagrams

The diagrams are also grabbed from the HTML pages from local PlantUML website:

# extract_diagrams.sh
find  'build/plantuml.com' \
    -name '*.html' \
    -exec \
        grep -R -a -P -z -o \
            '(?s)(@|@)startuml.+?@enduml' {} \+ \
    > "build/diagrams.txt"

4. Compare the result

By serving and surfing the content of the web/ directory, it is possible to compare the images as they they are used in the manual to the result of the generated diagrams.

The easiest way to to this is using PHP's built-in webserver:

 php -S "${IP:=127.0.0.1}:${PORT:=8080}" -t ./web/

The images used in the manual are now available at: http://${IP}:${PORT}/plantuml-diagrams.php.

The result of the rendered diagrams are now available at: http://${IP}:${PORT}/plantuml-images.php

5. Output diagrams

Once the result has been verified, the diagrams can be ouput as individual files:

php ./web/plantuml-diagrams.php

Please note that only the files that are visible when visiting http://${IP}:${PORT}/plantuml-diagrams.php will be stored as diagrams in build/diagrams.

Done

The individual diagrams will now be available in build/diagrams/

---

Footnotes

1. The PlantUML Themes project is yet to be open sourced. When it is, it will be linked from here.