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How to trace Javascript events (Stack Trace )?

In any programming language, I can trace any function and know which function is called by other. But in Javascript , I don't know how, since the code is not written by me and Firebug does not give this feature - as far as I know.

An example :

I want to display the function names of each function that is called when clicking on XYZ Element, and display them in order.

like image 431
Abdullah Avatar asked Jul 19 '10 17:07

Abdullah


2 Answers

Found this: A javascript stacktrace in any browser, James says they have a github account now

function printStackTrace() {
  var callstack = [];
  var isCallstackPopulated = false;
  try {
    i.dont.exist+=0; //doesn't exist- that's the point
  } catch(e) {
    if (e.stack) { //Firefox
      var lines = e.stack.split('\n');
      for (var i=0, len=lines.length; i<len; i++) {
        if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
          callstack.push(lines[i]);
        }
      }
      //Remove call to printStackTrace()
      callstack.shift();
      isCallstackPopulated = true;
    }
    else if (window.opera && e.message) { //Opera
      var lines = e.message.split('\n');
      for (var i=0, len=lines.length; i<len; i++) {
        if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
          var entry = lines[i];
          //Append next line also since it has the file info
          if (lines[i+1]) {
            entry += " at " + lines[i+1];
            i++;
          }
          callstack.push(entry);
        }
      }
      //Remove call to printStackTrace()
      callstack.shift();
      isCallstackPopulated = true;
    }
  }
  if (!isCallstackPopulated) { //IE and Safari
    var currentFunction = arguments.callee.caller;
    while (currentFunction) {
      var fn = currentFunction.toString();
      var fname = fn.substring(fn.indexOf("function") + 8, fn.indexOf('')) || 'anonymous';
      callstack.push(fname);
      currentFunction = currentFunction.caller;
    }
  }
  output(callstack);
}

function output(arr) {
  // Output however you want
  alert(arr.join('\n\n'));
}
like image 156
Allen Rice Avatar answered Nov 04 '22 08:11

Allen Rice


You can see the stack trace of any error with the stack() function call (on Firefox). Creating a simple function to print a stack trace could look like this:

function getStackTrace() {
  try {
    unusedVariable++; // This creates an error we can trace
  }
  catch (e) {
    return e.stack;
  }
}

Other browsers have different ways of printing the stack trace, but this should get you what you need for Firefox.

Hope this helps.

like image 41
godswearhats Avatar answered Nov 04 '22 10:11

godswearhats