topic Re: Webapp- Show points within a selected polygon in ArcGIS JavaScript Maps SDK Questions

Webapp- Show points within a selected polygon

RickeyFight — Wed, 31 Dec 2014 17:11:02 GMT

I have over 3 million points. I cannot have my server displaying all these points on a map a the same time.

What I want to do is when a building is selected, show all points within that polygon.

I know about this example:

Select with Feature Layer | ArcGIS API for JavaScript

I am not sure that will work because I don't want a buffer I want to use another Layer.

Thank you

Re: Webapp- Show points within a selected polygon

KellyHutchins — Wed, 31 Dec 2014 18:06:47 GMT

Yep you can use the same idea as the sample you linked to but instead of using a buffer you'll just use the geometry of the other layer. Here's an example that selects all the points within a census block group.

Select with feature layer

If you look at the code you'll see that we setup a click handler for the block feature layer and when its clicked we query the point feature layer using the clicked geometry.

Re: Webapp- Show points within a selected polygon

RickeyFight — Wed, 31 Dec 2014 20:01:10 GMT

That should work!

Thank you!

Re: Webapp- Show points within a selected polygon

RickeyFight — Thu, 16 Apr 2015 17:24:33 GMT

I was wondering if there is a way to have the selected census block highlighted as well?

It would be nice to know the boundary is for the block.

Is there a reason why when a geocoder is added it will not zoom to location?

Thank you!

Re: Webapp- Show points within a selected polygon

RobertScheitlin__GISP — Thu, 16 Apr 2015 18:09:07 GMT

Rickey,

Here is an updated version that adds the select block as well

Select with feature layer

Re: Webapp- Show points within a selected polygon

RickeyFight — Thu, 16 Apr 2015 18:45:36 GMT

Robert Scheitlin, GISP

That is exactly what I was looking for thank you!

Re: Webapp- Show points within a selected polygon

RickeyFight — Mon, 20 Apr 2015 15:04:21 GMT

So I am using polygons not points. Some polygons (soils) overlap some of the boundaries(taxlots).

For the life of me I cannot figure out how to change the color to indicate what polygon is selected(cyan outline).

It is confusing because there are so many features being selected.

The red taxlot is a boundary. Then two different features (soils) overlap that polygon are selected, indicated by a red dash.

When I select either polygon a cyan outline appears. This works when the map is zoomed out but when it is zoomed in it is impossible to tell what one is selected.

How do i change the color of the soils layer to indicate which one is selected?

Thank you

Re: Webapp- Show points within a selected polygon

RobertScheitlin__GISP — Mon, 20 Apr 2015 16:02:26 GMT

Rickey,

If I am understanding your concern then all you need to do is set the soil layer selection symbol. Look in the existing code for "setSelectionSymbol" for an example of the code syntax.

Re: Webapp- Show points within a selected polygon

RickeyFight — Mon, 20 Apr 2015 16:34:19 GMT

Robert,

Thank you for the quick reply!

I found the "setSelectionSymbol" you are talking about. When I add a color it changes the color of both polygons(soils) not the selected one.

// selection symbol used to draw the selected census block points within the buffer polygon

var symbol3 = new SimpleFillSymbol(SimpleFillSymbol.STYLE_SOLID,

new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT,

new Color([247, 34, 101]), 2), new Color([247, 34, 101, 0.25]));

censusPoints.setSelectionSymbol(symbol3);

I am looking for the selected one (cyan border) to change fill color when selected.

Re: Webapp- Show points within a selected polygon

RobertScheitlin__GISP — Mon, 20 Apr 2015 16:46:28 GMT

Rickey,

You have do the setSelectionSymbol for the soils layer the cyan outline is the selection symbol.

Re: Webapp- Show points within a selected polygon

helenchu — Mon, 09 May 2016 18:15:21 GMT

Thanks for the updated version. It's exactly what I'm looking for except that I'd like to have the grid table for the point attribute data. Best if it's edible table. If you know there's a webapp builder widget for it please let me know.

Much appreciated