Chrome Extension: Properly adding a context menu entry with non-persistent background page

Question

I'm working on a simple link sharing extension (pinboard, readability, delicious, etc), and have a question about how to properly deal with a context menu item. In my non-persistent background page I call chrome.contextMenus.create and chrome.contextMenus.onClicked.addListener to setup/respond to the context menu.

The context menu entry works as expected. But the background page is showing the following error (right after it starts and before I've used the entry) :

contextMenus.create: Cannot create item with duplicate id id_share_link at chrome-extension://.../share.js:52:30 lastError:29 set  

This made me realize that at no point do I remove the item or the listener. Knowing little about javascript and extensions, I'm left wondering if I'm doing everything correctly. I'm assuming this top-level code is going to re-execute every time the background page is invoked. So there are going to be redundant calls to create and addListener (and hence the error I see being logged).

I clearly can't do cleanup in response to suspend, as these calls need to be present to wake up the background script.

Should I be handling things differently?

Answer 1

You can handle it one of two ways:

1. You can add the context menu and the listeners on install using:

   chrome.runtime.onInstalled.addListener(function() {
     /* Add context menu and listener */
   });
   

2. You can remove the context menu and listener, and then re-add it each time the file is called.