Meteor Iron:Route with Meteor 1.2 - meteor

Question

I'm learning Meteor by following this tutorial.
Here is my git https://github.com/nicholaschong12/meteor-slackclone
I'm getting this error:
Uncaught TypeError: Cannot read property 'channel' of undefined
Uncaught TypeError: Function.prototype.apply: Arguments list has wrong
type
Meteor.startup(function(){
Session.set('channel',this.params.channel);
});
Please help me to understand this error.
Thank You

Answer 1

Looking at the error:
Uncaught TypeError: Cannot read property 'channel' of undefined
We can see that it is trying to read a property 'channel' of an undefined object. This object from your code is:
this.params
Reading the iron:router docs, tells us that:
When a user goes to that url, the actual value of the parameter will be stored as a property on this.params in your route function.
However in the code snippet you provided:
Meteor.startup(function(){
Session.set('channel',this.params.channel);
});
You are trying to access this.params inside a Meteor.startup callback function, not a Router.route function. In this context this.params is undefined, as the error is telling you.
Change your startup code to match the tutorial:
Meteor.startup(function() {
Session.set('channel', 'general');
});
And in your routing code you can use values from the route like this:
Router.route('/:channel', function () {
Session.set('channel', this.params.channel);
this.render('messages');
});
In this context this.params will return an object, including the channel property defined in the routes path.