Illustrator Script to apply Symbol to end points of selected lines

Hi Mike, grab the small white circle in your symbol and make a second symbol. I need just the white circle by itself to grab its dimensions. Name it "marker".

then select 1 or more path items and run this script

// place destination symbol
// carlos canto
// https://community.adobe.com/t5/illustrator/illustrator-script-to-apply-symbol-to-end-points-of-selected-lines/td-p/10928347?page=1

function main() {
    var idoc = app.activeDocument;
    var sel = idoc.selection;

    var p, pp, marker, endPoint, markerSymbol, endPointSymbol;
    markerSymbol = idoc.symbols['marker'];
    endPointSymbol = idoc.symbols['EndPoint'];

    marker = idoc.symbolItems.add(markerSymbol);

    for (var a=0; a<sel.length; a++) {
        if(sel[a].typename == "PathItem") {
            pp = sel[a].pathPoints;
            p = pp[pp.length-1];

            
            endPoint = idoc.symbolItems.add(endPointSymbol);
            
            endPoint.position = [p.anchor[0]-marker.width/2, p.anchor[1]+marker.height/2];
        }
    }

    marker.remove();

}

main();

There is a pretty easy way to add a circle or shape at the end of your line using your stroke panel. Make sure "show options" is selected on the stroke panel so that you can see the arrow menus. Then you can select your line, and choose what arrow symbol endpoint you'd like to apply.

here's how to add symbols to the canvas william

var idoc = app.activeDocument;
var endPointSymbol = idoc.symbols['EndPoint'];

var symbolInstance = idoc.symbolItems.add(endPointSymbol);

I can't figure out whether it's possible to place a symbol instance into the document via a script.. You can create an action to do so, but it's generic and requires the symbol to be pre-selected in the symbols panel.. So, i hope someone else has some advice on this portion..

But as to the rest of your question, here's a little snippet that shows how to position the symbol relative to an endpoint of a path. (you may need to fiddle with some buffer to get the circle of your symbol to line up properly. as it stands, this snippet will simply align the top left coordinate to the end of the line. So you'll probably need to add or subtract a few points to fine tune the positioning).

function alignSymbolToPathPoint()
{
	var docRef = app.activeDocument;
	var layers = docRef.layers;
	var myPath = layers[0].pageItems[0];
	var symbol = layers[0].pageItems[1];
	myPath.selected = true;

	symbol.position = myPath.selectedPathPoints[0].anchor;

	//use this one instead to get the other end of the path.
	// symbol.position = myPath.selectedPathPoints[myPath.selectedPathPoints.length-1].anchor;

}
alignSymbolToPathPoint();

How do you determine which end of the line is the endpoint and which one is the start point?