Help with function in JavaScript.

Question

Can someone help me with understanding why the addLayer() function is not working in my code. In the console it says it is not defined. JS API 4.18. I’m a bit new to JS and self-taught coder. So please bear with me. I can only get it to work when the addLayer() is outside of the

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Anonymous User · Answer

It's all good I really appericate the time you put into this.

But yeah I removed that second Portal Item.

I know how to create the Layer and add it to the map. It's not in the code I provided, It's just a simple console log. The key is to get that function to be added to each Portal Item (in for ForEach) button created when the createGallery function is triggered.

JeffreyWilkerson · Answer

I'm not familiar with the Portal object.  I looked at the 4.18 version and it doesn't have much of an example.  It seems you are doing what it says, initially, which is to create the Portal object, setup the query params and then run the query.  Not sure where the map is getting set (if at all) in that example.  In your code, after you create the Portal object and then set the query params and run the query, you then set up the Map and MapView.  Nowhere do I see the creation of a Featurelayer or other object that you can add to the Map to create a layer.  If the portal id that you obfuscated is supposed to be a Map with a Layer in it then I don't see a need to then create the Map and MapView.

Not sure if I can help you here, but to my previous points, there are 2 'portal.load' events that you should try to combine into 1 to see if that helps.  And the 'addLayer' functions are just that, functions that need to be called, not events.  If you are trying to get a reference to when the layer gets added, you may try something like:

// This function fires each time a layer view is created for a layer in
// the map of the view.
view.on("layerview-create", function(event) {
  // The event contains the layer and its layer view that has just been
  // created. Here we check for the creation of a layer view for a layer with
  // a specific id, and log the layer view
  if (event.layer.id === "satellite") {
    // The LayerView for the desired layer
    console.log(event.layerView);
  }
});

But I don't really see anywhere that a layer is being added.

If the item being reference is a layer, you might try getting it as a PortalItem and then adding it to the map, as in:

// to access the portal item at this url
// http://www.arcgis.com/home/item.html?id=d7892b3c13b44391992ecd42bfa92d01
var item = new PortalItem({
  id: "d7892b3c13b44391992ecd42bfa92d01"
});
if (item.isLayer) {
  Layer.fromPortalItem({
    portalItem: item
  }).then(addLayerToMap);
}

Sorry I can't help further.

Anonymous User · Answer

Thanks for the reply. 
I have those function in there 3 x because I was just showing that I tried different locations.

Yeah I'm just trying to get the function to work before I work on the actual Add Layer functions.

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