Sails JS: Pass parameter to toJSON - node.js

Question

The sailsjs model attribute method toJSON is very handy for processing model attributes before sending back to client. However, this method does not take any parameters and I cannot pass additional information to the method that can be used for processing attributes.
In my particular case, I need to check if I should send an attribute by comparing logged in user id (req.user.id). E.g.
toJSON: function () {
var obj = this.toObject();
var result = {};
if (req.user.id === 123) { // How can I access req from inside toJSON?
// do something here ...
}
}
I could not find a way to access the req parameter from inside toJSON. Any suggestions?

Answer 1

Sails does purposely not expose the req attribute as a global so there is no way to access it from within toJSON:
How to access session variables outside controller
Depending on the functionality you are trying to achieve you might be able to use policies instead: How to access request object in sails js lifecycle callbacks
In a similar case, I found myself using a workaround instead. You can add the id of the logged in user in your controller to the model:
YourModel.findOne().exec(function (err, yourModelObject) {
yourModelObject.loggedInUserId = req.user.id;
res.send(yourModelObject);
});
It is then accessible in your toJSON method and you could use it like this:
toJSON: function () {
var obj = this.toObject();
var result = {};
if (obj.loggedInUserId === 123) {
// do something here ...
}
delete obj.loggedInUserId;
return obj;
}
It is a little bit of a hack, but it worked for me. Be careful that a user can't somehow set the same value on the model (for example by using schema: true in your model) in question, to prevent security holes in your code.