wikiparser/README.md

wikiparser

Extracts articles from Wikipedia database dumps for embedding into the mwm map files created by the Organic Maps generator.

Extracted articles are identified by Wikipedia article titles in url or text form (language-specific), and Wikidata QIDs (language-agnostic). OpenStreetMap commonly stores these as wikipedia*= and wikidata= tags on objects.

Configuring

article_processing_config.json should be updated when adding a new language. It defines article sections that are not important for users and should be removed from the extracted HTML.

Usage

To use with the map generator, see the run.sh script and its own help documentation. It handles preparing the inputs, using multiple dumps, and re-running to convert titles to QIDs and extract them across languages.

To run the wikiparser manually or for development, see below.

First, install the rust language tools

For best performance, use --release when building or running.

You can run the program from within this directory using cargo run --release --.

Alternatively, build it with cargo build --release, which places the binary in ./target/release/om-wikiparser.

Run the program with the --help flag to see all supported arguments.

$ cargo run --release -- --help
Extract article HTML from Wikipedia Enterprise HTML dumps.

Expects an uncompressed dump connected to stdin.

Usage: om-wikiparser [OPTIONS] <OUTPUT_DIR>

Arguments:
  <OUTPUT_DIR>
          Directory to write the extracted articles to

Options:
      --write-new-ids <WRITE_NEW_IDS>
          Append to the provided file path the QIDs of articles matched by title but not QID.

          Use this to save the QIDs of articles you know the url of, but not the QID. The same path can later be passed to the `--wikidata-ids` option to extract them from another language's dump.

  -h, --help
          Print help (see a summary with '-h')

  -V, --version
          Print version

FILTERS:
      --wikidata-ids <WIKIDATA_IDS>
          Path to file that contains a Wikidata QID to extract on each line (e.g. `Q12345`)

      --wikipedia-urls <WIKIPEDIA_URLS>
          Path to file that contains a Wikipedia article url to extract on each line (e.g. `https://lang.wikipedia.org/wiki/Article_Title`)

It takes as inputs:

• A wikidata enterprise JSON dump, extracted and connected to stdin.
• A file of Wikidata QIDs to extract, one per line (e.g. Q12345), passed as the CLI flag --wikidata-ids.
• A file of Wikipedia article titles to extract, one per line (e.g. https://$LANG.wikipedia.org/wiki/$ARTICLE_TITLE), passed as a CLI flag --wikipedia-urls.
• A directory to write the extracted articles to, as a CLI argument.

As an example of manual usage with the map generator:

• Assuming this program is installed to $PATH as om-wikiparser.
• Download the dumps in the desired languages (Use the files with the format ${LANG}wiki-NS0-${DATE}-ENTERPRISE-HTML.json.tar.gz). Set DUMP_DOWNLOAD_DIR to the location they are downloaded.
• Run a maps build with descriptions enabled to generate the id_to_wikidata.csv and wiki_urls.txt files.
• Run the following from within the intermediate_data subdirectory of the maps build directory:

# Transform intermediate files from generator.
cut -f 2 id_to_wikidata.csv > wikidata_ids.txt
tail -n +2 wiki_urls.txt | cut -f 3 > wikipedia_urls.txt
# Enable backtraces in errors and panics.
export RUST_BACKTRACE=1
# Set log level to debug
export RUST_LOG=om_wikiparser=debug
# Begin extraction.
for dump in $DUMP_DOWNLOAD_DIR/*-ENTERPRISE-HTML.json.tar.gz
do
  tar xzf $dump | om-wikiparser \
    --wikidata-ids wikidata_ids.txt \
    --wikipedia-urls wikipedia_urls.txt \
    descriptions/
done