在 OpenLayers 6.9.0 中，我使用 fetch WMTSCapabilities 但它不起作用

Question

I use fetch WMTSCapabilities but I get this message: Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'Layer') at Function.rL.source.WMTS.optionsFromCapabilities (ol.js:2)

This is the code I use:

const parser = new ol.format.WMTSCapabilities();
let bgRaster;
fetch('data/WMTSCapabilities.xml')
  .then(function (response) {
    return response.text();
  })
  .then(function (text) {
    const result = parser.read(text);
    const options = ol.source.WMTS.optionsFromCapabilities(result, {
      layer: 'standaard',
      format: 'image/png',
      matrixSet: 'EPSG:28992',
    });
    bgRaster = new ol.layer.Tile({
          opacity: 0.7,
          source: new ol.source.WMTS(options),
          title: 'Kadaster',
          visible: false
        });
  })

Answer 1

Sorry, that I brought my question so bluntly. I didn't realize that my request was more or less a staement. Not my intention. IF you could help me out, I would be very pleased.

Regards Boudewijn van Os

Answer 2

This looks like it is failing at this line in optionsFromCapabilities from the OpenLayers source :

export function optionsFromCapabilities(wmtsCap, config) {
  const layers = wmtsCap['Contents']['Layer'];

Check that you are getting a valid WMTSCapabilities.xml including the Contents tag It should look similar to this xml

Answer 3

Thanks, I've got it working now with another approach, by programming origin,extend and resolution like this:

const size = ol.extent.getWidth(projectionExtent) / 256;
// Er zijn 20 (0 tot 19) zoomniveaus beschikbaar van de WMTS-service voor de BGT-Achtergrondkaart:
let matrixIds = new Array(20);
for (let z = 0; z < 10; ++z) {
    matrixIds[z] = 'EPSG:3857:0' + z;
}
for (let z = 10; z < 20; ++z) {
    matrixIds[z] = 'EPSG:3857:' + z;
}
const bgRaster = new ol.layer.Tile({
  extent: projectionExtent,
  source: new ol.source.WMTS({
 attributions: 'Kaartgegevens: &copy; <a href="https://www.kadaster.nl">Kadaster</a>',
                url: 'https://service.pdok.nl/brt/achtergrondkaart/wmts/v2_0?',
                layer: 'standaard',
                matrixSet: 'EPSG:3857',
                format: 'image/png',
                projection: projection,
                tileGrid: new ol.tilegrid.WMTS({
                    origin: ol.extent.getTopLeft(projectionExtent),
  //                  origin: -285401.92 + "," + 903402.0,
                    resolutions: resolutions,
                    matrixIds: matrixIds
                }),
                style: 'default',
                wrapX: false
  }),
      title: 'Kadaster',
      visible: true
});