Allow to run Meteor server-methods only when user is logged in

Question

I've played for a while with Meteor, and have now some server methods published to the client with Meteor.methods({...})

For now I'm checking on the beginning of every method, if the user is logged in. Is it possible to write this code more aspect oriented, and check this on another, more centralised place? Similar to the way Meteor.Collection is checked with .allow? I would want the user to be logged in for most of the methods, if not all of them.

Is there maybe some execution pipeline on the server, where I could plug in functions to do this?

Answer 1

I've wanted to do something like this for a while.

This is what I have so far:

// function to wrap methods with the provided preHooks / postHooks. Should correctly cascade the right value for `this`
function wrapMethods(preHooks, postHooks, methods){
  var wrappedMethods = {};
  // use `map` to loop, so that each iteration has a different context
  _.map(methods, function(method, methodName){
    wrappedMethods[methodName] = makeFunction(method.length, function(){
      var  _i, _I, returnValue;
      for (_i = 0, _I = preHooks.length; _i < _I; _i++){
        preHooks.apply(this, arguments);
      }
      returnValue = method.apply(this, arguments);
      for (_i = 0, _I = postHooks.length; _i < _I; _i++){
        postHooks.apply(this, arguments);
      }
      return returnValue;
    });
  });
  return wrappedMethods;
}

// Meteor looks at each methods `.length` property (the number of arguments), no decent way to cheat it... so just generate a function with the required length
function makeFunction(length, fn){
  switch(length){
    case 0: 
      return function(){ return fn.apply(this, arguments); };
    case 1:
      return function(a){ return fn.apply(this, arguments); };
    case 2:
      return function(a, b){ return fn.apply(this, arguments); };
    case 3:
      return function(a, b, c){ return fn.apply(this, arguments); };
    case 4:
      return function(a, b, c, d){ return fn.apply(this, arguments); };
    // repeat this structure until you produce functions with the required length.
    default:
      throw new Error("Failed to make function with desired length: " + length)
  }
}

If you wanted to put this in to separate files / packages, you'll need to change function wrapMethods(...){...} to wrapMethods = function(...){...}

Example Usage, checking the user is valid before a method call:

function checkUser(){
  check(this.userId, String);
}
Meteor.methods(wrapMethods([checkUser], [], {
  "privilegedMethod": function(a, b, c){
    return true;
  }
}));