generate the value of key dynamically in localforage

Question

I'm using localForage to store data offline. While adding key-value to store with setItem method, i want to generate the value of key like activity_1, activity_2, activity_3, etc, and this are generated when i submit the form. So for every form that i submit it should generate the key value differently.

Here is the code for that:

var getActivity = document.getElementById('getActivity'),
    fetchVal = document.getElementById('fetchVal'),
    log_form = document.getElementById('log_form');

function activityArr() {
  var i = 1;
  if(i > 0){
    var keyVal = 'activity_' + i;
  }
  i++;
  return keyVal;
}

log_form.addEventListener('submit', function(e){
  e.preventDefault();
  localforage.setItem(activityArr(), getActivity.value)
    .then(function (val) {
      console.log(val);
    }).catch(function(err){
      console.log(err);
    });
    localforage.keys().then(function(keys) {
    console.log(keys);
}).catch(function(err) {
    console.log(err);
});
});

Here's the codepen link for reference.

But in my case it generates key 'activity_1' for every form that i submit. So it overrides the previous value that is stored at 'activity_1'.

Just try to submit the form 2-3 times, and open your developer console to see the result.

How do i generate keys differently whenever i submit the form.

Answer 1

Don't make the i variable local. Every time the function is called, the i variable is reset to 1.

var i = 1;
function activityArr() {
  if(i > 0){
    var keyVal = 'activity_' + i;
  }
  i++;
  return keyVal;
}