Is there a way to configure the Basemap Gallery to import basemaps from gallery in another Portal?

[FranklinAlexander]

We are migrating all of our web applications (mostly built with WAB or EB developer) from on premise servers to Azure Cloud (ArcGIS Enterprise) servers. This also means that all of the associated data, web maps, etc. will also be migrated which requires re-sourcing the applications and all associated widgets to the newly migrated maps and data. This cannot be done from within the developer environment (gui) which leaves us with 2 options. Rebuild the applications in the EB Dev version registered to the portal to where the associated maps and data have been migrated, or use a code editor to modify the app config files with the new map ids, and layer urls. Since we have over 20 apps to migrate, the first option is not viable and I have been successful modifying the config files without breaking the apps. The side effect to this strategy is that that I am now editing an application in a version of EB developer registered in a portal that doesn't match the portal where the map and data are located. Because of this, even though I created a custom BM Gallery containing US Edition basemaps in the target portal, I have no way of importing them into the Basemap Widget. Also, unlike the success I had with the web map and other data sources, modifying the BM Gallery json in the config file doesn't work for some reason. I also tried adding the basemaps by URL, but I don't know exactly how to configure the URL correctly. I can tell you that if I paste the URL into a browser window it take me to the ArcGIS Portal Directory page for the item and the BM Gallery is also shared with the public. Appreciate any ideas on how to proceed, or does this require a custom Basemap Gallery widget? Not sure what's going on under the hood with the Basemap Gallery and I really don't have the time to try and modify the widget code.

[TonghuiMing · Accepted solution]

Hi @FranklinAlexander, based on the screenshot, you added the portal/AGOL item URL, which would not be recognized by the basemap gallery widget, as expected. Have you tried using the URL of the basemap layer itself? The acceptable types include imagery layers, imagery tile layers, map image layers, tile layers, or vector tile layers.

In addition, you may find this helpful - https://developers.arcgis.com/rest/basemap-styles/ 

Hope it helps with your case.

[FranklinAlexander]

@TonghuiMing Thanks for the response and the suggestion. I did find a URL for the World Topographic Map (US Edition), but when I copy and paste the URL from the item details into the URL input, it ends up being the wrong map (see map below). 

This layer contains the 'Gulf of Mexico' label and according to the item description should contain the 'Gulf of America' label. 

I was able to find the URLs for the US Edition basemaps, but it was no small task and have copied them to a spreadsheet for future reference. lol  The only way I was able to find URLs to the US Edition maps was to load them one at a time into the map viewer and follow the link in the Information property which leads to the root.json of the basemap. Be nice if there was an Esri docs page that listed the URLs for these basemaps, I always find them to be challenging to work with. 

However, what I said above about the Topo URL is still perplexing to me.