How to set attribute d pf path element in Angular 2?

I am working on a Angular2 Project.

  class Coordinate {
      x:number;
      y:number;
    }

    class Data {
     .....
     coordinates: Array<Coordinate>;
     .........
    }

This is a service file. I am using this service to access data in my Component's .ts file.

I want to use coordinates array to draw polyline on svg. In the template file, I am trying to set attribute 'd' of path element but can't figure out the right syntax to do so.

Following is the section of .html file of the component

<div>
 <svg>
  <path [[How am I supposed to set the d attribute here]]/>
 </svg>
</div>

Solution

In Angular svg requires some special treatment. This is a very good article about the issue: http://teropa.info/blog/2016/12/12/graphics-in-angular-2.html

Now in your case in the template it should be:

<div>
 <svg viewBox="0 0 480 480" preserveAspectRatio="xMidYMid meet" width="100%" height="100%" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <svg:g>
      <svg:path [attr.d]="yourVarThatStoresPathString"></svg:path>
    </svg:g>
  </svg>
</div>

In your ts file you should add logic that results in path string (like for example yourVarThatStoresPathString = "M0,0 480,0 480,480 0,480 0,0").

So if you have array of coordinates (x,y) you might need a function that translates that into such a string. Also in SVG there are additional literas (letters) used to identify specifics around a coordinate like M0,0 - means move pencil to 0,0 and start drawing, or Z after the coordinate may mean - link this last coordinate with the first.

Just as example:

let pathPoints = [
            {
                l: "M",
                x: 135.00,
                y: 245.00,
                s: " "
            },
            {
                l: "",
                x: 135.00,
                y: 110.00,
                s: " "
            },
            {
                l: "",
                x: 345.00,
                y: 110.00,
                s: " "
            },
            {
                l: "",
                x: 345.00,
                y: 245.00,
                s: " "
            },
            {
                l: "",
                x: 345.00,
                y: 380.00,
                s: " "
            },
            {
                l: "",
                x: 135.00,
                y: 380.00,
                s: " "
            },
            {
                l: "",
                x: 135.00,
                y: 245.00,
                s: "Z"
            },
]

l = letters, s - spacer I use for convenience.

constructPath(pathPoints) {
  let pathD = "";
  pathPoints.forEach((coordinate) => {
    pathD = pathD + coordinate.l + coordinate.x + "," + coordinate.y + item.s;
    });
  return pathD;
  }
}

This is of course a bit pseudo code but should give you a direction.