How to get the spatialReference of a Basemap

NicoleSchmidt

Is there a way to get access to the spatialReference of the basemap?  This seems like it should be simple.  I should be able to create the basemap from the portalId and check the spatial reference to predict whether the load will fail.  I have tried checking baselayers, I have tried calling .load on the basemap and .load on the baselayers then checking the spatialReference.   It is still null.

Will Esri eventually handle changing spatial references of a mapview when a user chooses a basemap that is in a different spatial reference from the currently loaded mapView?

RobertScheitlin__GISP

Nicole,

   I don't know how to do it without loading the portal item. Here is my code for loading the item and checking the spatialReference:

<SPAN class="operator token"><</SPAN><SPAN class="operator token">!</SPAN>DOCTYPE html<SPAN class="operator token">></SPAN>
<SPAN class="operator token"><</SPAN>html<SPAN class="operator token">></SPAN>
<SPAN class="operator token"><</SPAN>head<SPAN class="operator token">></SPAN>
&nbsp; <SPAN class="operator token"><</SPAN>meta charset<SPAN class="operator token">=</SPAN><SPAN class="string token">"utf-8"</SPAN><SPAN class="operator token">></SPAN>
&nbsp; <SPAN class="operator token"><</SPAN>meta name<SPAN class="operator token">=</SPAN><SPAN class="string token">"viewport"</SPAN> content<SPAN class="operator token">=</SPAN><SPAN class="string token">"initial-scale=1,maximum-scale=1,user-scalable=no"</SPAN><SPAN class="operator token">></SPAN>
&nbsp; <SPAN class="operator token"><</SPAN>title<SPAN class="operator token">></SPAN>Load a basic WebMap <SPAN class="operator token">-</SPAN> <SPAN class="number token">4.5</SPAN><SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>title<SPAN class="operator token">></SPAN>

&nbsp; <SPAN class="operator token"><</SPAN>style<SPAN class="operator token">></SPAN>
&nbsp;&nbsp;&nbsp; html<SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp; body<SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp; #viewDiv <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; padding<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; margin<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; height<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">100</SPAN><SPAN class="operator token">%</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; width<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">100</SPAN><SPAN class="operator token">%</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp; <SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>style<SPAN class="operator token">></SPAN>

&nbsp; <SPAN class="operator token"><</SPAN>link rel<SPAN class="operator token">=</SPAN><SPAN class="string token">"stylesheet"</SPAN> href<SPAN class="operator token">=</SPAN><SPAN class="string token"><SPAN>"</SPAN><A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.5%2Fesri%2Fcss%2Fmain.css" target="_blank">https://js.arcgis.com/4.5/esri/css/main.css</A><SPAN>"</SPAN></SPAN><SPAN class="operator token">></SPAN>

&nbsp; <SPAN class="operator token"><</SPAN>script src<SPAN class="operator token">=</SPAN><SPAN class="string token"><SPAN>"</SPAN><A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.5%2F" target="_blank">https://js.arcgis.com/4.5/</A><SPAN>"</SPAN></SPAN><SPAN class="operator token">></SPAN><SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>script<SPAN class="operator token">></SPAN>

&nbsp; <SPAN class="operator token"><</SPAN>script<SPAN class="operator token">></SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="token function">require</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="string token">"esri/views/MapView"</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="string token">"esri/WebMap"</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="string token">"esri/portal/PortalItem"</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="string token">"dojo/domReady!"</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; MapView<SPAN class="punctuation token">,</SPAN> WebMap<SPAN class="punctuation token">,</SPAN> PortalItem
&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">/************************************************************
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * Creates a new WebMap instance. A WebMap must reference
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * a PortalItem ID that represents a WebMap saved to
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * arcgis.com or an on-premise portal.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * To load a WebMap from an on-premise portal, set the portal
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * url with esriConfig.portalUrl.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ************************************************************/</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> webmap <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">WebMap</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; portalItem<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">{</SPAN> <SPAN class="comment token">// autocasts as new PortalItem()</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; id<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"f2e9b762544945f390ca4ac3671cfa72"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">/************************************************************
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; * Set the WebMap instance to the map property in a MapView.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ************************************************************/</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> view <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">MapView</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; map<SPAN class="punctuation token">:</SPAN> webmap<SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; container<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"viewDiv"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; view<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><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> item <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">PortalItem</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; id<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"6d4b8b5b8a174c20b55b0934941030f4"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; item<SPAN class="punctuation token">.</SPAN><SPAN class="token function">load</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; item<SPAN class="punctuation token">.</SPAN><SPAN class="token function">fetchData</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"json"</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>rslt<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; console<SPAN class="punctuation token">.</SPAN><SPAN class="token function">info</SPAN><SPAN class="punctuation token">(</SPAN>rslt<SPAN class="punctuation token">.</SPAN>spatialReference<SPAN class="punctuation token">.</SPAN>wkid<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp; <SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>script<SPAN class="operator token">></SPAN>
<SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>head<SPAN class="operator token">></SPAN>

<SPAN class="operator token"><</SPAN>body<SPAN class="operator token">></SPAN>
&nbsp; <SPAN class="operator token"><</SPAN>div id<SPAN class="operator token">=</SPAN><SPAN class="string token">"viewDiv"</SPAN><SPAN class="operator token">></SPAN><SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>div<SPAN class="operator token">></SPAN>
<SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>body<SPAN class="operator token">></SPAN>

<SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>html<SPAN class="operator 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>‍</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><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>