Convert ESRI styles to OpenLayers styles

Info

This module can convert ESRI style definition to OpenLayers style function. ESRI style definition must be in JSON format - https://developers.arcgis.com/documentation/common-data-types/renderer-objects.htm

Getting started

Import as ES6 module:

import { createStyleFunction, createStyleFunctionFromUrl } from 'ol-esri-style';

// create a new vector layer
const vector = new VectorLayer({
  ...
});
const proj = map.getView().getProjection();

// set layer style directly from the layer URL
// Passing the projection is need for labeling features. Visible resolutions for
// the labels are calculated using map projection units.
createStyleFunctionFromUrl('arcgis_server_layer_url', proj).then(styleFunction => {
  vector.setStyle(styleFunction);
});

// You can also retrieve the layer info yourself and use it to create the style
// function
fetch(`${arcgis_server_layer_url}?f=json`)
    .then(res => res.json())
    .then(json => createStyleFunction(json, proj))
    .then(styleFunction => {
        vector.setStyle(styleFunction);
    });

You can modify the styles before applying them to the features:

// set layer style
createStyleFunctionFromUrl('arcgis_server_layer_url').then(styleFunction => {
  vector.setStyle((feature, resolution) => {
    const styles = styleFunction(feature, resolution);

    // modify styles

    return styles;
  });
});