This repository contains 2 programs which shall do the same thing.
- One written in Python
- On written in Rust.
The Python version is developed to a partially useful state, described below.
The Rust version is an "exercise" for me. I wantedn to explore how achieve the same functionality in Rust. It is not yet finished, but i am convinced that it can be done in a very similar way.
Current resume:
- Rust is a little more difficult as a language (at least for me and currently).
- The ecosystem is comparable to Python in many respects.
Program to extract approach charts into pdf documents from the German AIP-VFR.
The pdfs are formatted in a way that most of them can be directly printed as an A5-foldable approach chart. This is true for the common three-piece apprach charts for small airports.
For IFR airports and perhaps some VFR fields the pdf is currently unusable. (Working on it...) In this case you can still create your own documents from the downloaded images using LibreOffice, OpenOffice, MS-Word or whatever program works for you.
It is only useful for iterating over a subsection of the AD part. It is not yet possible to fetch all charts of the AD part without fetching lots of unneccessary pages.
When doing too many fetches from one IP address, the AIP website will block that address. I am not sure whether the limit allows to fetch all charts, so a selection mechanism should be esablished...
Perhaps the blockade can be avoided by throttling the fetches.
The German AIP-VFR is organized in a tree-structure, resembling the chapters of the AIP.
The AIP website is quite regularly organized and easy to parse. All relevant tags are decorated with distinct css and other attributes and thus simple to address.
There are "folder-links", which point to a sub-page, and there are "document-links", which point to html documents containing the final data.
This data is always a PNG image with the chart or text.
The program iterates the tree, creates the respective folders in the file system and, for the documents, downloads the image files. Due to a restriction in the next step, the PNG files are converted to JPEG before saving them.
Then, it assembles the images into a PDF document per folder. For most small airports, this is usable as a neatly foldable A5 approach chart. For some (ifr and e.g. EDHE) it will currently be crap.
The AIP website uses the concept or "permalinks", i.e. known links which do not change between AIP cycles. These links are addressing small "stub" pages which redirect into the "real" tree (with monthly changing adresses.) The redirect mechanism might be a bit unusual, it is handled be a "reload" instruction.
This redirect is recognized and handled by the program too, so you can use any permalink as entry point for the scan.