Question

I am using a gem to implement an event calendar on a website. It is the event_calendar gem.

I am getting the following error in chrome:

Uncaught TypeError: Object function Event() { [native code] } has no method 'observe'

It is generated in line 6 of event_calendar.js:

Event.observe(window, "load", function() {

Any ideas as of what is wrong?

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I have a model called Event, so I suspect that it might somehow be interfering with the JS, but I’m not able to find that anywhere in my code.

What I find strange is that the event calendar works, with events and all. Could this be some issue with duplication? Again, I can’t find any signs of this.

Answer 1

Sorry I might be a little late, I have just encountered the same issue and have managed to fix this error.

The event_calendar gem has implemented a couple of different implementation for different Javascript libraries.
By default when you run

rails generate event_calendar

it does not generate the jquery’s implementation which your rails app is most likely using.

The Event.observe pattern is a prototype.js function. Unless your rails app has included prototype.js first before the event_calendar gem, it will break.

To fix your problem, if you are using jquery as your default javascript library, you could run

1. rails generate event_calendar --use-jquery

2. then replace the app/assets/javascripts/event_calendar.js with the generated public/javascripts/event_calendar.js.

Hope it helps.