How to Ensure GeoJsonLayer's Spatial Reference is the same as View's Spatial Reference

[developerarce]

Hi, I have a pretty interesting task which involves rendering the map with a GeoJSON layer and symbols for the data. I then need to take a screenshot of this map. The map is being rendered off screen on purpose and the screenshot is being taken programmatically via arcGis API. When the view is ready, I go to the desired location of the geojson with 0 animation.

The problem I am having, is the screenshot is empty. I believe the map and geojson with symbol doesn’t appear to be rendered yet. I am watching for the update on the view for when it is done moving to the location and then timing out for 2s. It inconsistently takes a screenshot.

Is there some process to know when the map and all the layers are done rendering? 


So, after further investigation, `queryExtent()` in combination with `goTo()` (https://developers.arcgis.com/javascript/latest/sample-code/featurelayer-queryextent/) is actually zooming in so far that the screen turns white. The GeoJsonLayer I have is definitely big enough that it covers like 10 square meters. However, if I click the Zoom (-) button 3 times, I can see my layer just fine now.

So, I think I know what the issue is. The spatial reference of the GeoJSONLayer is different than the View's spatial reference. Should I be setting the GeoJSONLayer spatial reference to be equal to the View?

[IhabHassan]

Hi @developerarce 

I would suggest checking this code sample: https://developers.arcgis.com/javascript/latest/sample-code/watch-for-changes/

It demonstrate how to check the status of the map view if moving/panning or at stationary. You can extend it to check for layers properties like "loadStatus" to detect if a layer finished loading or still loading.

Regards

Ihab

[developerarce]

So, I think I know what the issue is. The spatial reference of the GeoJSONLayer is different than the View's spatial reference. Should I be setting the GeoJSONLayer spatial reference to be equal to the View?

[MehdiPira1 · Accepted solution]

@developerarce ,

Yes, I'd recommend to make them both have the same spatial reference.

The following link is a good example of how to change view's spatial reference / projection. You can also add the GeoJSONLayer's spatial reference to the dropdown list in the code to check it out:

https://developers.arcgis.com/javascript/latest/sample-code/layers-hosted-imagerytilelayer-landcover...

[developerarce]

Yeah, I think that's my issue with `queryExtent()` because the view is in Web Mercator and the GeoJSONLayer is in WSG84, so when we `gotTo()` on the view using the extent of the GeoJSONLayer. Going to give this a shot really quick.