Restart SVG animation sequence from Javascript

Question

I'm trying to restart SVG animation sequence from Javascript. Restart-button below will broke SVG animation sequence. How to restart/reset entire sequence?

document.getElementById("button").addEventListener("click", function() {
  document.getElementById("fore").beginElement();
});

<svg version="1.1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 150">
  <path id="track" fill="none" stroke="#000000" stroke-width="1" stroke-dasharray="10,10" d="M 50 100 L 950 50"/>
  <path id="plane" d="M-10 -10 L10 0L-10 10z" fill="red" />

  <animateMotion xlink:href="#plane" 
    id="fore" 
    begin="0s;back.end" 
    dur="2s" 
    fill="freeze" 
    repeatCount="1" 
    rotate="auto" 
    keyPoints="0;1" 
    keyTimes="0;1"
   ><mpath xlink:href="#track" /></animateMotion>
  
  <animateMotion xlink:href="#plane" 
    id="back" 
    begin="fore.end"  
    dur="2s" 
    fill="freeze" 
    repeatCount="1" 
    rotate="auto-reverse" 
    keyPoints="1;0" 
    keyTimes="0;1"
   ><mpath xlink:href="#track" /></animateMotion>
</svg>

<button id="button">RESTART</button>

Answer 1

You can use setCurrentTime on the entire svg element. I added an id of svgEl to the svg node and then when rest is clicked we do:

document.getElementById('svgEl').setCurrentTime(0);

Have a look at this:

document.getElementById("button").addEventListener("click", function() {
  document.getElementById('svgEl').setCurrentTime(0);
});

<svg id="svgEl" version="1.1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 150">
  <path id="track" fill="none" stroke="#000000" stroke-width="1" stroke-dasharray="10,10" d="M 50 100 L 950 50"/>
  <path id="plane" d="M-10 -10 L10 0L-10 10z" fill="red" />

  <animateMotion xlink:href="#plane" 
    id="fore" 
    begin="0s;back.end" 
    dur="2s" 
    fill="freeze" 
    repeatCount="1" 
    rotate="auto" 
    keyPoints="0;1" 
    keyTimes="0;1"
    restart="always"
   ><mpath xlink:href="#track" /></animateMotion>
  
  <animateMotion xlink:href="#plane" 
    id="back" 
    begin="fore.end"  
    dur="2s" 
    fill="freeze" 
    repeatCount="1" 
    rotate="auto-reverse" 
    keyPoints="1;0" 
    keyTimes="0;1"
    restart="always"
   ><mpath xlink:href="#track" /></animateMotion>
</svg>

<button id="button">RESTART</button>