topic Re: How to find Begin and End points of a polyline using Arcgis Javascript in ArcGIS JavaScript Maps SDK Questions

How to find Begin and End points of a polyline using Arcgis Javascript

viteboardviteboard — Thu, 26 Sep 2013 12:07:37 GMT

Hello All,

Can anyone say how to get the starting and ending points of a polyline when we draw using Arcgis Javascript api.
Using WebAdf we are having the facility of MapLineEventArgs.BeginMapPoint and MapLineEventArgs.EndMapPoint.
I want to perform few validation basing on this start and end coordinates of polyline

Thank You
Aravind

Re: How to find Begin and End points of a polyline using Arcgis Javascript

JasonZou — Fri, 10 Dec 2021 23:40:00 GMT

You can use polyline.getPoint(pathIndex,pointIndex) function to get the point you need. For instance,

First point of the first path:

polyline.getPoint(0,0)

Last point of the first path:

var lastIdx = polyline.paths[0].length - 1;
var lastPnt = polyline.getPoint(0, lastIdx)

Re: How to find Begin and End points of a polyline using Arcgis Javascript

viteboardviteboard — Thu, 26 Sep 2013 13:10:21 GMT

Thank you..It solved my problem.

Re: How to find Begin and End points of a polyline using Arcgis Javascript

JasonZou — Thu, 26 Sep 2013 13:12:56 GMT

Glad to help. Please consider mark your thread as "Answered" so other people may find it helpful. Thanks.

Re: How to find Begin and End points of a polyline using Arcgis Javascript

JohnGrayson — Fri, 27 Sep 2013 15:30:40 GMT

Careful, the previous solution assumes the geometry is a single-part polyline, which seems to be ok for this use case, but might not work in all situations, like when the geometry is retrieved from an external source like a Map or Feature Service.

var lastPartIdx = polyline.paths.length-1;
var lastPntIdx = polyline.paths[lastPartIdx].length - 1;
var lastPnt = polyline.getPoint(lastPartIdx , lastPntIdx);