Files
openlayers/examples/geojson-vt.js
Tim Schaub 054af09032 Make code prettier
This updates ESLint and our shared eslint-config-openlayers to use Prettier.  Most formatting changes were automatically applied with this:

    npm run lint -- --fix

A few manual changes were required:

 * In `examples/offscreen-canvas.js`, the `//eslint-disable-line` comment needed to be moved to the appropriate line to disable the error about the `'worker-loader!./offscreen-canvas.worker.js'` import.
 * In `examples/webpack/exapmle-builder.js`, spaces could not be added after a couple `function`s for some reason.  While editing this, I reworked `ExampleBuilder` to be a class.
 * In `src/ol/format/WMSGetFeatureInfo.js`, the `// @ts-ignore` comment needed to be moved down one line so it applied to the `parsersNS` argument.
2020-04-06 12:54:09 -06:00

105 lines
2.4 KiB
JavaScript

import GeoJSON from '../src/ol/format/GeoJSON.js';
import Map from '../src/ol/Map.js';
import OSM from '../src/ol/source/OSM.js';
import Projection from '../src/ol/proj/Projection.js';
import VectorTileSource from '../src/ol/source/VectorTile.js';
import View from '../src/ol/View.js';
import {
Tile as TileLayer,
VectorTile as VectorTileLayer,
} from '../src/ol/layer.js';
// Converts geojson-vt data to GeoJSON
const replacer = function (key, value) {
if (value.geometry) {
let type;
const rawType = value.type;
let geometry = value.geometry;
if (rawType === 1) {
type = 'MultiPoint';
if (geometry.length == 1) {
type = 'Point';
geometry = geometry[0];
}
} else if (rawType === 2) {
type = 'MultiLineString';
if (geometry.length == 1) {
type = 'LineString';
geometry = geometry[0];
}
} else if (rawType === 3) {
type = 'Polygon';
if (geometry.length > 1) {
type = 'MultiPolygon';
geometry = [geometry];
}
}
return {
'type': 'Feature',
'geometry': {
'type': type,
'coordinates': geometry,
},
'properties': value.tags,
};
} else {
return value;
}
};
const map = new Map({
layers: [
new TileLayer({
source: new OSM(),
}),
],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
const url = 'data/geojson/countries.geojson';
fetch(url)
.then(function (response) {
return response.json();
})
.then(function (json) {
const tileIndex = geojsonvt(json, {
extent: 4096,
debug: 1,
});
const vectorSource = new VectorTileSource({
format: new GeoJSON({
// Data returned from geojson-vt is in tile pixel units
dataProjection: new Projection({
code: 'TILE_PIXELS',
units: 'tile-pixels',
extent: [0, 0, 4096, 4096],
}),
}),
tileUrlFunction: function (tileCoord) {
const data = tileIndex.getTile(
tileCoord[0],
tileCoord[1],
tileCoord[2]
);
const geojson = JSON.stringify(
{
type: 'FeatureCollection',
features: data ? data.features : [],
},
replacer
);
return 'data:application/json;charset=UTF-8,' + geojson;
},
});
const vectorLayer = new VectorTileLayer({
source: vectorSource,
});
map.addLayer(vectorLayer);
});