More info on Maps and Layers

[Rob]

My requirements:

• Ability for user to add shapes (rectangle, square, circle) or image to a map.
• Ability for the user to move that shape around on a map (drag and drop).
• Ability for the user to save all the placed shape geolocations.
• Ability to read the saved shape geolocations and place them on the map.

I did a little research on your Map control and it does seem to support layers and a specific layer  type called "shape".  However, when I look at the code sample I don't see any way to define the shape (circle, rectangle, etc.) nor provide dimensions for the shape (L X W) nor have a bitmap/image as a shape?

I also didn't see any drag and drop support?

Could I get answers to these questions and/or point me to documentation that supports my requirements?

Cheers, Rob.

[Dimo]

Hello Rob,

Indeed, the listed requirements are currently not supported. I am sorry if this forces you to look for another third-party component. In addition -

• We have a feature request about drawing shapes on the Map, but it covers API for drawing by the application, and not by the user.
• The Shape layer works with GeoJSON data. The linked specification describes how to define shapes like points, polygons, etc.

Regards,
Dimo
Progress Telerik

[Rob]

Thanks for the response Dimo.  To clarify, the shapes will be predefined, the user will not draw or create the shapes, they will select predefined shapes and place them on a map.

Look at the GeoJSON data it seems this might work:

{
           "type": "Feature",
           "geometry": {
               "type": "Polygon",
               "coordinates": [
                   [
                       [100.0, 0.0],
                       [101.0, 0.0],
                       [101.0, 1.0],
                       [100.0, 1.0],
                       [100.0, 0.0]
                   ]
               ]
           }

But it sounds like you don't support drag/move of these shapes and placement on the map?

Do you have any recommendations for alternate controls/tools that might work with Blazor and easy to implement?  We currently operate Blazor server-side but I guess we can do hybrid if needed.  I'm not a fan of JS (in fact I hate it) but that said, if we have to use JS then so be it.

[Dimo]

If shape dragging is not a strict must, then a lot easier option is to select a shape from outside the Map and then click on the Map to place it - the component will tell you where the user clicked.

Otherwise, a custom drag and drop implementation will require you to infer Map coordinates from JavaScript pointer events, which will be quite an adventure, to put it mildly.