How to workaround FB is not defined

Question

Sometimes I m getting the  FB is not defined  issue when loading the http   connect facebook net en US all js   I ve realized that the problem is because sometimes my website just doesn t load that file  So it gets nothing  and the object FB literally doesn t exist   My solution is to prevent my users when this happens  so I ve tried the following codes in JavaScript but none seems to work   if  FB     run the app    else    alert the user    if  FB   false     run the app    else    alert the user    if  FB   undefined      run the app    else    alert the user      thanks for the answer

User · Accepted Answer

Assuming FB is a variable containing the Facebook object, I'd try something like this:

if (typeof(FB) != 'undefined'
     && FB != null ) {
    // run the app
} else {
    // alert the user
}

In order to test that something is undefined in plain old JavaScript, you should use the "typeof" operator. The sample you show where you just compare it to the string 'undefined' will evaluate to false unless your FB object really does contain the string 'undefined'!

As an aside, you may wish to use various tools like Firebug (in Firefox) to see if you can work out why the Facebook file is not loading.

User · Answer

I had a similar issue and it turned out to be Adblocker Pro  Be sure to check that this or other blocking extensions have been disabled  I lost around 1hr 30 mins due to this  Feel like such a noob

User · Answer

FB recommends to add the async all js include right after body  so that FB object get prepared when you use it in page   You can also have artificial delay using setTimeout to make sure FB object is loaded  e g    lt script gt setTimeout function    FB Event subscribe  edge create   function  response        alert  msg via fb         2000    lt  script gt

User · Answer

I think you should solve the main issue instead  which solution is provided by Facebook  Loading the SDK Asynchronously         You should insert it directly after the opening  tag on each page you want to load it     lt script gt    window fbAsyncInit   function         FB init         appId         your-app-id         xfbml        true        version       v2 1                   function d  s  id        var js  fjs   d getElementsByTagName s  0        if  d getElementById id    return        js   d createElement s   js id   id       js src      connect facebook net en US sdk js        fjs parentNode insertBefore js  fjs        document   script    facebook-jssdk      lt  script gt    From the documentation        The Facebook SDK for JavaScript doesn t have any standalone files that   need to be downloaded or installed  instead you simply need to include   a short piece of regular JavaScript in your HTML that will   asynchronously load the SDK into your pages  The async load means   that it does not block loading other elements of your page    UPDATE  using the latest code from the documentation

User · Answer

I guess you missed to put semi-colon   at the closing curly brace   of window fbAsyncInit   function

User · Answer

I had FB never being defined   Turned out that I was prototyping functions into the Object class called  merge  and another called  toArray   Both of these screwed up Facebook  no error messages but it wouldn t load   I changed the names of my prototypes  it works now   Hey  if Facebook is going to prototype Object  shouldn t I be allowed to prototype it

User · Answer

There is solution for you     You must run your script after window loaded  if you use jQuery  you can use simple way    lt div id  fb-root  gt  lt  div gt   lt script gt      window fbAsyncInit   function             FB init               appId         your-app-id               xfbml        true              status       true              version       v2 5                           function d  s  id           var js  fjs   d getElementsByTagName s  0           if  d getElementById id    return           js   d createElement s   js id   id          js src      connect facebook net en US sdk js           fjs parentNode insertBefore js  fjs         document   script    facebook-jssdk      lt  script gt    lt script gt    window  load function         var comment callback   function response            console log  comment callback            console log response             FB Event subscribe  comment create   comment callback       FB Event subscribe  comment remove   comment callback        lt  script gt

User · Answer

lt script gt        window fbAsyncInit   function                 FB init                     appId        your-app-id                     xfbml       true                    version      v2 1                          function d  s  id            var js  fjs   d getElementsByTagName s  0           if d getElementById id                 return                         js   d createElement s            js id   id               js src      connect facebook net en US  sdk js                fjs parentNode insertBefore js  fjs              document  script   facebook-jssdk      lt  script gt     From the documentation  The Facebook SDK for JavaScript doesn t have any standalone files that need to be downloaded or installed  instead you simply need to include a short piece of regular JavaScript in your HTML tha

User · Answer

It s pretty strange for FB not to be loaded in your javascript if you have the script tag there correctly  Check that you don t have any javascript blockers  ad blockers  tracking blockers etc installed in your browser that are neutralizing your FB Connect code

User · Answer

You were very close with your original example  You could either use  jAndy s suggestion or   if  typeof FB     undefined

User · Answer

For people who still got this FB bug  I use this cheeky fix to this problem   Instead of http   connect facebook net en US all js  I used HTTPS and changed it into https   connect facebook net en US all js and it fixed my problem

User · Answer

lt  head gt   lt body gt       lt  -- Load Facebook SDK for JavaScript -- gt       lt div id  fb-root  gt  lt  div gt   lt script type  text javascript  gt        Check div id  fb-root   div      It s very important to run

[javascript] How to workaround 'FB is not defined'?

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