Typeerror: analytics.push is not a function (firefox 23.0.1)

[mickdelaney]

I'm getting a problem with the script loader on firefox.
Its happening intermittently.

its happening on the line below in the script loader from usedhttps://segment.io/libraries/analytics.js.

any ideas?

<script type="text/javascript"> // Create a queue, but don't obliterate an existing one! var analytics = analytics || []; (function () { // A list of all the methods we want to generate queueing stubs for. var methods = [ 'identify', 'track', 'trackLink', 'trackForm', 'trackClick', 'trackSubmit', 'page', 'pageview', 'ab', 'alias', 'ready', 'group' ]; // For each of our methods, generate a queueing method that pushes arrays of // arguments onto our `analytics` queue. The first element of the array // is always the name of the analytics.js method itself (eg. `track`), so that // we know where to replay them when analytics.js finally loads. var factory = function (method) { return function () { analytics.push([method].concat(Array.prototype.slice.call(arguments, 0))); }; }; for (var i = 0; i < methods.length; i++) { analytics[methods[i]] = factory(methods[i]); } }()); // Define a method that will asynchronously load analytics.js from our CDN. analytics.load = function (apiKey) { // Create an async script element for analytics.js based on your API key. var script = document.createElement('script'); script.type = 'text/javascript'; script.async = true; script.src = ('https:' === document.location.protocol ? 'https://' : 'http://') + 'd2dq2ahtl5zl1z.cloudfront.net/analytics.js/v1/' + apiKey + '/analytics.min.js'; // Find the first script element on the page and insert our script next to it. var firstScript = document.getElementsByTagName('script')[0]; firstScript.parentNode.insertBefore(script, firstScript); }; // Load analytics.js with your API key, which will automatically load all of the // analytics integrations you've turned on for your account. Boosh! analytics.load('mycode'); </script>

[mickdelaney]

looks like the code got cleaned out from the original issue...
the line is this one below:

// For each of our methods, generate a queueing method that pushes arrays of
// arguments onto our analytics queue. The first element of the array
// is always the name of the analytics.js method itself (eg. track), so that
// we know where to replay them when analytics.js finally loads.
var factory = function (method) {
return function () {
analytics.push([method].concat(Array.prototype.slice.call(arguments, 0)));
};
};

[mickdelaney]

strange... am assuming another script is adding 'analytics' to the global... but only happens on FF

[hrdwdmrbl]

I get this ALL the time! It drives me nuts!

I already check to make sure analytics isn't added as a global before analytics.js loads.
I have debugged all the way to checking the state of analytics at the time .push is called.

analytics.push //undefined

I wrapped the call analytics.push([e].concat(Array.prototype.slice.call(arguments, 0))); in a try/catch, and at the time of the error, .push is undefined.

I've attached a screenshot of the FF representation of the analytics object at the time of the issue. It is definitely some sort of race condition, because later on all function calls work fine.
The problem occurs for me when I call identify, but I think it would happen for any method call.
I am currently using the .ready(fun... callback provided by analytics.

[hrdwdmrbl]

I actually get this in Chrome (Version 29.0.1547.65) too.

Uncaught TypeError: Object #<S> has no method 'push'                        analytics.js?body=1:15

[hrdwdmrbl]

I tried not using the analytics.ready(fun... callback, but still get the error.

[ianstormtaylor]

Hey guys, really sorry about this! A couple questions to help debugging:

1. Do you have this live at a URL I can debug at by any chance?
2. Are you using the snippet verbatim from our setup guide? or with AMD, etc.?
3. Do you know when you started noticing this happening? or has it always been there for you?

Thanks!

[hrdwdmrbl]

@ianstormtaylor

1. Yes, our staging environment. Can you email me for the link? I'm marc@lagoa.com
2. Snippet verbatim.
3. Going through our git history, I first had to account for .push not being there 23 days ago. I worked around it at first by implementing this hack though

if(!analytics.push){
    analytics.push = Array.prototype.push.bind(analytics);
} 

[ianstormtaylor]

Hey guys, it looks like the issue is that you've inlined the script in your application's Javascript. But if you want to do that, you need to make sure the first line where it says var analytics = ... actually references window.analytics instead creating a closured variable.

So if you switch those lines to window.analytics you should see the problem disappear.

I'm going to add an issue to change the snippet to between with, since that will eliminate this problem from ever cropping up again.

[mickdelaney]

Can you paste the solution in here. i've tried using window.analytics n still get an issue.

[hrdwdmrbl]

Yes, I still get the issue as well. :(

[ianstormtaylor]

Ah sorry, so basically in the snippet, every reference you see to the analytics variable should say window.analytics instead. Does that make sense?

[ianstormtaylor]

Okay, another cause could be, when the analytics.js library loads from the server, it replaces the window.analytics global with the "real" analytics object. (That has the real versions of all of the methods stubbed out in the snippet.) If you are keeping the reference to the old analytics object around, that will fail. Instead you need to always be referencing window.analytics. For example, AMD module wrappers won't work.

We have a fix for this coming, but it's not ready yet. In the meantime, just use window.analytics.

[hrdwdmrbl]

Ah, I was able to fix the problem with that bit of knowledge. Basically I had kept a reference to the old object around. Thanks!

[gingerlime]

I still seem to experience this issue, even after replacing all analytics with window.analytics. Could someone share a working snippet please?