不支持背景manifest.json

Question

A Chrome app had a function that I wanted to emulate. Essentially, the manifest.json calls a script (main.js) that causes the window to open and size the html a certain way.

So instead of loading the html directly, its supposed to preload and execute this script before, so that the app feels more complete and encapsulated. Now when I side load the app (to test it) I have no issues. But when I go to upload it, I get an error.

Now since I know that this manifest and script works sideloaded and on this other uploaded app, I have no idea how I'm supposed to be able to get it to upload without the error.

  An error occurred: Failed to process your item. background subsection of app section is not supported. 

This is the part of the manifest that is getting the error:

 "app": {
      "background": {
         "scripts": [ "main.js" ]
      }    },

Is there a way to get this script to work or get the effect of it through some other way?

here is the main.js script:

/**
 * Listens for the app launching then creates the window
 *
 * @see http://developer.chrome.com/trunk/apps/app.runtime.html
 * @see http://developer.chrome.com/trunk/apps/app.window.html
 */
chrome.app.runtime.onLaunched.addListener(function() {
  // Center window on screen.
  var screenWidth = screen.availWidth;
  var screenHeight = screen.availHeight;
  var width = 1280;
  var height = 720;

  chrome.app.window.create('index.html', {
    bounds: {
      width: width,
      height: height,
      left: Math.round((screenWidth-width)/2),
      top: Math.round((screenHeight-height)/2)
    }
  });
});

Answer 1

The whole process stops working if the first upload was with

"app": {
      "launch": {
         "local_path": "index.html"
      }    },

I clicked on "Add New Item" and by uploading the first file with the "background" "scripts" instead of "launch" it accepted the zip file with no issues.

I guess it just means that if you have to submit it as a brand new item to begin with, if you want it to be a packaged app.