Using function() to create dynamic response

Question

The following code works:

tooltipOpts: {
  content: "%s : %y",
  shifts: {
  x: -30,
  y: -50
  }
}

I am trying to show some dynamically calculated data in "content" so am trying to use a function. Even my most basic example isn't working, I get error shown below:

 tooltipOpts: {
   content: function() {
     return "%s : %y";
   },
   shifts: {
     x: -30,
     y: -50
   }
 }


Uncaught TypeError: Object function () {
    return "%s : %y";
} has no method 'replace' 

Answer 1

I'll assume you are using the tooltip plugin from here. I've coded up a fiddle example, here, that uses the function format of the content property. Note that your callback signature it incorrect:

content: function(label, xval, yval, flotItem){ // expects to pass these arguments
    return "%s : %y";
},

But even without those arguments, I couldn't reproduce your error.