Edit

Example of using the OSM XML source.

OSM XML vector data is loaded dynamically from a the Overpass API using a bbox strategy. Note that panning and zooming will eventually lead to "Too many requests" errors from the Overpass API.

main.js
import Map from 'ol/Map';
import OSMXML from 'ol/format/OSMXML';
import VectorSource from 'ol/source/Vector';
import View from 'ol/View';
import XYZ from 'ol/source/XYZ';
import {Circle as CircleStyle, Fill, Stroke, Style} from 'ol/style';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer';
import {bbox as bboxStrategy} from 'ol/loadingstrategy';
import {transformExtent} from 'ol/proj';

let map = null;

const styles = {
  'amenity': {
    'parking': new Style({
      stroke: new Stroke({
        color: 'rgba(170, 170, 170, 1.0)',
        width: 1,
      }),
      fill: new Fill({
        color: 'rgba(170, 170, 170, 0.3)',
      }),
    }),
  },
  'building': {
    '.*': new Style({
      zIndex: 100,
      stroke: new Stroke({
        color: 'rgba(246, 99, 79, 1.0)',
        width: 1,
      }),
      fill: new Fill({
        color: 'rgba(246, 99, 79, 0.3)',
      }),
    }),
  },
  'highway': {
    'service': new Style({
      stroke: new Stroke({
        color: 'rgba(255, 255, 255, 1.0)',
        width: 2,
      }),
    }),
    '.*': new Style({
      stroke: new Stroke({
        color: 'rgba(255, 255, 255, 1.0)',
        width: 3,
      }),
    }),
  },
  'landuse': {
    'forest|grass|allotments': new Style({
      stroke: new Stroke({
        color: 'rgba(140, 208, 95, 1.0)',
        width: 1,
      }),
      fill: new Fill({
        color: 'rgba(140, 208, 95, 0.3)',
      }),
    }),
  },
  'natural': {
    'tree': new Style({
      image: new CircleStyle({
        radius: 2,
        fill: new Fill({
          color: 'rgba(140, 208, 95, 1.0)',
        }),
        stroke: null,
      }),
    }),
  },
};

const vectorSource = new VectorSource({
  format: new OSMXML(),
  loader: function (extent, resolution, projection, success, failure) {
    const epsg4326Extent = transformExtent(extent, projection, 'EPSG:4326');
    const client = new XMLHttpRequest();
    client.open('POST', 'https://overpass-api.de/api/interpreter');
    client.addEventListener('load', function () {
      const features = new OSMXML().readFeatures(client.responseText, {
        featureProjection: map.getView().getProjection(),
      });
      vectorSource.addFeatures(features);
      success(features);
    });
    client.addEventListener('error', failure);
    const query =
      '(node(' +
      epsg4326Extent[1] +
      ',' +
      Math.max(epsg4326Extent[0], -180) +
      ',' +
      epsg4326Extent[3] +
      ',' +
      Math.min(epsg4326Extent[2], 180) +
      ');rel(bn)->.foo;way(bn);node(w)->.foo;rel(bw););out meta;';
    client.send(query);
  },
  strategy: bboxStrategy,
});

const vector = new VectorLayer({
  source: vectorSource,
  style: function (feature) {
    for (const key in styles) {
      const value = feature.get(key);
      if (value !== undefined) {
        for (const regexp in styles[key]) {
          if (new RegExp(regexp).test(value)) {
            return styles[key][regexp];
          }
        }
      }
    }
    return null;
  },
});

const key = 'Get your own API key at https://www.maptiler.com/cloud/';
const attributions =
  '<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' +
  '<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>';

const raster = new TileLayer({
  source: new XYZ({
    attributions: attributions,
    url: 'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
    maxZoom: 20,
  }),
});

map = new Map({
  layers: [raster, vector],
  target: document.getElementById('map'),
  view: new View({
    center: [739218, 5906096],
    maxZoom: 19,
    zoom: 17,
  }),
});
index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>OSM XML</title>
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/[email protected]/dist/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>
package.json
{
  "name": "vector-osm",
  "dependencies": {
    "ol": "7.0.0"
  },
  "devDependencies": {
    "vite": "^3.0.3",
    "@babel/core": "latest"
  },
  "scripts": {
    "start": "vite",
    "build": "vite build"
  }
}