Hello,
Can Graphics Layers be Queried? I cannot see anywhere that says that they cannot.
I know that CSV Layers cannot be queried.
Thanks,
Chris
In the 4.xyz API a layer view can be queried for a graphics layer the same way you would query the layer view for a feature layer:
<SPAN class="comment token"><SPAN>// source: </SPAN><A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fdevelopers.arcgis.com%2Fjavascript%2Flatest%2Fapi-reference%2Fesri-layers-FeatureLayer.html" target="_blank">https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-FeatureLayer.html</A></SPAN> <SPAN class="comment token">// returns all the graphics from the layer view</SPAN> view<SPAN class="punctuation token">.</SPAN><SPAN class="token function">whenLayerView</SPAN><SPAN class="punctuation token">(</SPAN>lyr<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">then</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>lyrView<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> lyrView<SPAN class="punctuation token">.</SPAN><SPAN class="token function">watch</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"updating"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>val<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> <SPAN class="keyword token">if</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="operator token">!</SPAN>val<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> <SPAN class="comment token">// wait for the layer view to finish updating</SPAN> lyrView<SPAN class="punctuation token">.</SPAN><SPAN class="token function">queryFeatures</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">then</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>results<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> console<SPAN class="punctuation token">.</SPAN><SPAN class="token function">log</SPAN><SPAN class="punctuation token">(</SPAN>results<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="comment token">// prints all the client-side graphics to the console</SPAN> <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN> <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>
You could pass a Query into layerView.queryFeatures with an extent geometry and the 'intersects' spatial relationship to query for features inside an extent. See Query | API Reference | ArcGIS API for JavaScript 4.3 for more details.
If you're using the 3.xyz API, my bet would be that you could easily write a query method yourself by accessing each graphic in a graphics layer and using the geometry engine to test each one. This is not an approach that scales especially well. I'm not sure if layerView.queryFeatures scales very well either.
Hi @RyanSutcliffe , did you manage to get this to work for querying a GraphicsLayer? Would you be open to sharing a code snippet? Thank you very much!
Taking a second look this morning I see how you can take a collection of graphics and set them as a source for a new FeatureLayer. That way you have access to queryFeatures and related functionality. I thought that a FeatureLayer required a REST endpoint or Map/FeatureService as it's source.
I could be wrong but I don't see how you can get a LayerView class from a GraphicsLayer. Seems a GraphicsLayer creates a GraphicsLayerView which only has queryGraphics(). The example and link above works only for a FeatureLayer. If either of you were indeed able to do the above would love to see a code sample of how you got this: specifically a LayerView from a GraphicsLayer in a map.
Thank you all for the feedback!
Chris,
The simple answer is No. But you could manually query the GL by looping through it's graphics and checking the graphics attributes.
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