Question

I am making a test extension but the item is not appearing in context menu. What is wrong here?

My manifest file

{
 "name": "Colour",
 "version": "1.0.1",
 "description": "Colour the background on right clicking image.",
 "offline_enabled": true,
 "permissions" : [
 "contextMenus",
   "tabs",
   "http://*/*",
   "https://*/*"
 ],
 "background_page":"background.html"
}

My background.html contains this script

function getColour(info, tab){
  document.body.style.background="#456";
}

chrome.contextMenus.create({
  "type":"normal",
  "title":"Colour page",
  "contexts":["image"],
  "onclick":getColour()
});

Answer 1

A reference to the getColour function has to be passed. It should not be invoked:

function getColour(info, tab){
    document.body.style.background="#456";
}

chrome.contextMenus.create({
    "type": "normal",
    "title": "Colour page",
    "contexts": ["image"],
    "onclick": getColour // <--- Removed ()
});

Previously, your code would work in this way:

1. getColour() – Calls getColour.
2. There is no return statement in the function, so it returns undefined.
3. chrome.contextMenu.create({ ... "onclick": undefined }); – No event handler!