open2json

Collect and merge drinking fountains from wikidata and OpenStreetMap

Demo

A working version of the code can be found here: link

Using open2json in a front-end project

If your code runs in the browser without transpiling, then include the prepackaged code in your HTML head:

<script src='https://github.com/mmmatthew/open2json/dist/open2json.min.js'></script>

You can then obtain data asynchronously:

<script>

    // create provider
    let provider = new open2json.Provider();

    // perform query (on osm and wikidata simultaneously. results are conflated to gether.)
    // calling without arguments uses default options and a bounding box for Basel, Switzerland
    provider.query()
    .then(data => {
        // do something with the data (it is a geojson)
    })
    .catch(error => {
        // if an error occurs you can do something with it here.
    })

</script>

Using open2json via npm install

> npm install --save open2json

You can then use open2json in your code:

var open2json = require('open2json');

// define options to use everywhere
var options = {};

let provider = new open2json.Provider(options); // etc.

Options

The query function takes an optional options argument with the following default values:

• overpassTagFilters (array of strings): Array of tag filters for querying OSM as defined here.
• overpassUrl (string): Url root for overpass. There are several defined here
• overpassTimeout (number): Number of seconds before overpass query should time out.
• wdLangs (string): List of language codes to be used for obtaining object label from Wikidata, in order of preference.
• wdEntityClasses (array of strings): Array of Wikidata entity IDs for filtering results
• wdImageWidth (integer): width of image for which a url is to be provided
• conflateRadius (integer): Wikidata objects are matched with the closest OpenStreetMap object that is within this distance (in meters)

The default values for these options are defined as follows:

const defaultOptions = {   
  overpassTagFilters: [
    'amenity=drinking_water',
    'drinking_water=yes',
  ],
  overpassUrl: 'https://z.overpass-api.de/api/interpreter',
  wdLangs: 'en,de,fr,it,es',
  wdEntityClasses: [
    'Q1630622', // drinking water fountain (Q1630622)
    'Q483453', // fountain (Q483453)
    'Q43483', // water well (Q43483)
  ],
  wdImageWidth: 350, // width in pixels of image to return (just url)
  conflateRadius: 10, // search radius for fountains, in meters
}

Using unit functions

var open2json = require('open2json')

var bbox = {
    lonMin: 8.53,
    latMin: 47.37,
    lonMax: 8.55,
    latMax: 47.38
};

var options = {
    overpassTagFilters: [
    'drinking_water=yes'
  ]
};

var standardWikiGeoJson, standardOsmGeoJson;

// just get data from wikidata without any processing
open2json.queryWikidata(bbox, options).then(wikidataJson => {
    // standardize a typical Wikidata response
    standardWikiGeoJson = open2json.standardizeWikidata(wikidataJson);
})

// just get data from Osm without any processing
open2json.queryOsm(bbox, options).then(OsmJson => {
    // standardize a typical Osm response
    standardOsmGeoJson = open2json.standardizeOsm(OsmJson);
})

// conflate two standardized geojsons. This can only be run once both GeoJsons have been loaded
var conflated = open2json.conflate(standardOsmGeoJson, standardWikiGeoJson);

Read the docs

Find the docs here: link

• query OpenStreetMap: link
• query Wikidata: link
• standardize OpenStreetMap: link
• standardize Wikidata: link
• conflate: link
• do everything at once with the query method of Provider: link

For contributors

Build open2json

• install NodeJS
• clone this repo
• in the directory that the code was cloned into, run npm install in the command line
• to build the module, run npm run build. This transpiles the TypeScript to Javascript (output into /lib directory) and packages the module for loading into a module (output into /dist/webpack directory). Additionally, the documentation is generated in the dist/docs directory.

Other commands

• test the code: run npm run test
• increment the package version: run npm version [patch | minor | major]
• publish to npm: run npm run publish

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