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I am adding layers to my map dynamically based on whats available in the MapServer. I am looping over them so I can add them in the LayerControl. My issue is that I dont have access to the layers outside of the scope of the function which I need to run a map.hasLayer() function. What can I do to access the layers outside the fetch function to perform removeLayer and other things?

let url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Energy/Infrastructure/MapServer";
  let serviceUrl = url+'?f=pjson';
  fetch(serviceUrl, {method:"get"})
  .then(function(response) {
    return response.json();
  })
  .then(function(esriService) {
    esriService.layers.forEach(function(layer) {
      let layerName = layer.name.replace(/\s/g, "");
      let fullName = layer.name // return string
      layerName = L.esri.dynamicMapLayer({
        url: url,
        layers: [layer.id]
      }).addTo(map);
      layerControl.addOverlay(layerName, fullName)
    })
  });

map.on('click', function (e) {
  if (!map.hasLayer(mydefinedlayer)) {
    console.log("Layer not displayed on map")
  } else {
    console.log("Layer displayed on map")
  }
});

1 Answer 1

3

Just keep their names in an array in the window object, such as:

window.dynamicLayerNames = [];
let url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Energy/Infrastructure/MapServer";
  let serviceUrl = url+'?f=pjson';
  fetch(serviceUrl, {method:"get"})
  .then(function(response) {
    return response.json();
  })
  .then(function(esriService) {
    esriService.layers.forEach(function(layer) {
      let layerName = layer.name.replace(/\s/g, "");
      let fullName = layer.name // return string
      layerName = L.esri.dynamicMapLayer({
        url: url,
        layers: [layer.id]
      }).addTo(map);
      layerControl.addOverlay(layerName, fullName);
      window.dynamicLayerNames.push(layerName);
    })
  });
3
  • Thanks will have a go with that. Not sure if the hasLayer() function can take the layer itself or if it has to be the variable name of the layer
    – geogrow
    Feb 9, 2019 at 11:38
  • I think it did work, that you. That will move me forward
    – geogrow
    Feb 9, 2019 at 12:07
  • Method map.hasLayer() requires layer object. It worked because what you call layerName in your code is actually layer object.
    – TomazicM
    Feb 9, 2019 at 12:12

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