Practicing with Javascript Loops or Optimization

Question

I'm still trying to practice making my code smaller. I know there's gotta be a better way to write this out using a loop. Can someone help me out?

Template.project.helpers({
  cell1: function() {
    return Session.get('cell1');
  },
  cell2: function() {
    return Session.get('cell2');
  },
  cell3: function() {
    return Session.get('cell3');
  },
  cell4: function() {
    return Session.get('cell4');
  },
  cell5: function() {
    return Session.get('cell5');
  },
  cell6: function() {
    return Session.get('cell6');
  },
  cell7: function() {
    return Session.get('cell7');
  },
  cell8: function() {
    return Session.get('cell8');
  },
  cell9: function() {
    return Session.get('cell9');
  }
});

There probably is, if it were clear what you want to *do*. An anonymous object, wrapped in parentheses -- none of these functions can ever be called. — Paul Roub, Dec 03 '15 at 16:06
since the code is 99% alike, why not a common method that is `cell: function (index) { Session.get('cell' + index); }` — epascarello, Dec 03 '15 at 16:09
Question is probably better suited for http://codereview.stackexchange.com/ — epascarello, Dec 03 '15 at 16:10
@epascarello CR wants full, working code for review and possible improvement. This would be rejected without first being edited into something useful. — Paul Roub, Dec 03 '15 at 16:13
What is this code actually? A parameter list for a function call? — Teemu, Dec 03 '15 at 16:14
@PaulRoub Which would be easy to stub out to make it valid on there. People do not know that place exists... — epascarello, Dec 03 '15 at 16:18
sorry I've updated to make it less anonymous, my bad @PaulRoub — jaruesink, Dec 03 '15 at 16:42

mk. · Accepted Answer · 2015-12-03T17:20:31.957

1

Try this:

var cells = {};
for (i = 1; i <= 9; i++) {
  cells["cell" + i] = function(cell) {
      return function() {
        Session.get("cell" + cell);
      }
  }(i);
}

The only tricky part is that if you don't include that secondary function, with its own closure, your function will use the outer closure and the value of cell will be 9 in all cases.

edited Dec 03 '15 at 17:20

answered Dec 03 '15 at 16:14

mk.

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this was close, the cells["cell" + cell] needed to be cells["cell" + i], thanks! – jaruesink Dec 03 '15 at 16:54

score 0 · Answer 2 · answered Dec 03 '15 at 16:37

I would take a function, because of the object needs a string for the access and that is exacly what the function needs as well.

function getSession(s) {
    Session.get(s);
}

The difference is, the object has for any possible sting an own property and it stores only the call with the given property. As long as there are not other dependent code in the objects methods, i would not use it in the OP's style.

If the object should work like a filter, that only some strings are allowed to use, then i would take this solution:

function getSession(s) {
    ~['cell1', 'cell2', 'cell3', 'cell4', 'cell5'].indexOf(s) && Session.get(s);
}

Practicing with Javascript Loops or Optimization

2 Answers2