How do I obtain attributes of polygons that intersect another polygon?

HarlanMarshall

I need to get all polygons from a given layer that intersect with a given polygon. In addition to the intersection geometry, I need to know which polygons (IDs) produce those intersections and some other attributes from the intersecting polygons. The geometryEngine.intersect() returns the intersection geometries only. What's the best way to get the attributes along with the geometries?

Thanks to anyone who can help or give me a sample.

ThomasSolow

Okay, you should be able to manually query the feature service for graphics (which will include attributes).

I would load all features when the page loads and then query against those features based on the user input later.  Revised sample:

<SPAN class="comment token">// do this on page load</SPAN>
<SPAN class="keyword token">let</SPAN> featureLayer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">FeatureLayer</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp; url<SPAN class="punctuation token">:</SPAN> <SPAN class="operator token"><</SPAN>FeatureLayer URL<SPAN class="operator token">></SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp; outFields<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">"*"</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

<SPAN class="keyword token">let</SPAN> allPolygons <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
featureLayer<SPAN class="punctuation token">.</SPAN><SPAN class="token function">load</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>fl <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">{</SPAN>
&nbsp; featureLayer<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>results <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp; allPolygons <SPAN class="operator token">=</SPAN> results<SPAN class="punctuation token">.</SPAN>features<SPAN class="punctuation token">;</SPAN>
&nbsp; <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="comment token">// call this when user submits polygon to query against all other</SPAN>
<SPAN class="comment token">// polygons</SPAN>

<SPAN class="keyword token">function</SPAN> <SPAN class="token function">findPolygons</SPAN><SPAN class="punctuation token">(</SPAN>searchPolygon<SPAN class="punctuation token">,</SPAN> graphics<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp; <SPAN class="comment token">// if there's no graphics then there are no intersections</SPAN>
&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>graphics<SPAN class="punctuation token">.</SPAN>length <SPAN class="operator token">===</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp; <SPAN class="comment token">// test each of them using geometryEngine.intersects against the search polygon</SPAN>
&nbsp; <SPAN class="keyword token">return</SPAN> graphics<SPAN class="punctuation token">.</SPAN><SPAN class="token function">filter</SPAN><SPAN class="punctuation token">(</SPAN>graphic <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> geometryEngine<SPAN class="punctuation token">.</SPAN><SPAN class="token function">intersects</SPAN><SPAN class="punctuation token">(</SPAN>graphic<SPAN class="punctuation token">.</SPAN>geometry<SPAN class="punctuation token">,</SPAN> searchPolygon<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>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

I should mention that if the graphics returned by the manual query don't have attributes, you may have to pass in a Query to queryFeatures.  The query needs a .where of "1=1" and an outFields of "*."  Let me know if you run into difficulties with that.