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Is it possible to perform the equivalent of "select by location" in the ArcGIS Server JavaScript API v4.x? The use-case is "find features in Layer 1 which are within x kilometres of features in Layer 2".

Here are the options I've considered:

  • a QueryTask with Query.geometry - this will query an entire layer, but only has the option to query against a single geometry object, not another layer
  • GeometryEngine.intersect - only works between 2 geometry objects, not 2 layers
  • The FindExistingLocations spatial analysis service, which seems to require special licensing which I don't have (I don't have access to ArcGIS Portal on this project)
  • Use the GeometryEngine.intersect approach in a JavaScript loop - which would require comparing every feature in both layers against each other (?)

I'm a little surprised that something so commonplace in a desktop GIS doesn't seem to be easily achievable in a web map. Am I missing something obvious?

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In the absence of a better answer, here's what I've come up with.

For each feature in Layer 2:

  • GeometryEngine.buffer the feature's geometry to create the "within X km" buffer
  • run QueryTask.execute() against Layer 1, where query.geometry is the buffer polygon
  • batch the QueryTasks to avoid overloading the server with too many concurrent queries
  • de-duplicate the returned features (if there are overlapping buffers, features will be returned multiple times)
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  • What about adding a GeometryEngine.Union between the buffer and the query? then you get a dissolved buffer and can query only once. Commented Dec 9, 2020 at 11:13
  • That's an excellent suggestion and it may work well for some cases. After testing, however, I found that it's actually a lot slower to run one mega-query than running a series of smaller queries. Also a series of smaller queries means I can show a progress bar. But many thanks for the suggestion Commented Dec 11, 2020 at 3:47
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You can add Sketch widget to create a graphicslayer and use that geometry to select features in target featurelayer. Sketch widget

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  • Thanks for the suggestion. However in my case I want to "find features in Layer 1 which are within x kilometres of features in Layer 2" rather than finding features which intersect with a polygon drawn manually by the user Commented Mar 25, 2021 at 23:10

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