Running a jQuery function multiple times sequentially (for a Bookmarklet)

Question

I've got the following jQuery code which I use in a Bookmarklet. It clicks on all the buttons on the page (with the class "Unfollow") one by one, with a random time between each one...

javascript: (function() {
    var unfollowButtons = $('button.Unfollow');
    var index = unfollowButtons.length - 1;
    unfollow();

    function unfollow() {
        if (index >= 0) {
            $(unfollowButtons[index--])
                .click();
            setTimeout(unfollow, Math.floor((Math.random() * 1000) + 500));
        }
    }
})();

I'd like to run the above function again twice once it has completed its cycle.

Just running the function again causes that to run in parallel with the first function call.

How do I run the unfollow() function 2 or 3 times without them all running in parallel?

Answer 1

Try it this way (using ES6 Promises):

var runUnfollow = function() {
  return new Promise(function(resolve, reject){
    var index = unfollowButtons.length - 1;

    // fencepost for the loop
    var p = Promise.resolve();

    // we stop execution at `i == 0`
    for (var i = index; i >= 0; i--) {
      // run the promise
      // then set `p` as the next one
      p = p.then(unfollowTimeout.bind(null, i));
    }
    // make sure we run the last execution at `i == 0`.
    p.then(function(){
      resolve();
    })

    function unfollowTimeout(i){
      // return a promise to run `unfollow` and a `setTimeout`
      return new Promise(function(resolve,reject){
         unfollow(i);
         setTimeout(resolve, Math.floor((Math.random() * 1000) + 500));
      })
    }
    function unfollow(i) {
      $(unfollowButtons[i])
        .click();
    }
  })
}

// run three times synchronously
runUnfollow().then(runUnfollow).then(runUnfollow).then(function(){
  //finished
});

// another way to run three times synchronously
p = runUnfollow();
for(i=3; i > 0; i--){
  p = p.then(runUnfollow);
}
p.then(function(){
  //finished
});

// run in parallel
Promise.all([runUnfollow, runUnfollow, runUnfollow])
  .then(function(){
    //finished
  });

EDIT: Went back and read your question again, realized you were trying to run everything multiple times. I've edited to reflect that.

Answer 2

Just reset index and restart after each button is clicked:

javascript: (function() {
    var unfollowButtons = $('button.Unfollow');
    var index = unfollowButtons.length - 1;
    var totalRuns = 3;
    unfollow();

    function unfollow() {
        if (index < 0 && totalRuns) {
            totalRuns--;
            unfollowButtons = $('button.Unfollow');
            index = unfollowButtons.length - 1;
        }

        if (index >= 0) {
            $(unfollowButtons[index--])
                .click();
            setTimeout(unfollow, Math.floor((Math.random() * 1000) + 500));
        }
    }
})();