Google chrome extension cookie help!

I need my chrome extension to read a value of a cookie set by a rails app, I did just try and use plain javascript to achieve this but kept getting the result of the cookie as null.

As I understand it you have to use the Chrome c开发者_JS百科ookie API to read them? I'm totally clueless when it comes to chrome extensions, I'm struggling with what the structure should be for the extensions i.e. A Background page, popup or a content script??

Ideally I want the popup.html to iterate through the values in the cookie that is sent, so I would strip the cookie for the values which would then be written to the popup.html file.

Any ideas or suggestions where to start?

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The only way you can read your sites cookies is by Content Scripts.

Since you wanted to do that in a popup.html page, you have two choices:

1. Tabs API - chrome.tabs.executeScript
2. Messaging API - chrome.tabs.sendRequest

Once you are in the content script, you can communicate to that pages Cookies.

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Currently the best (the simplest) way to get site cookies in extension is like this:

chrome.cookies.get({ url: 'http://example.com', name: 'somename' },
  function (cookie) {
    if (cookie) {
      console.log(cookie.value);
    }
    else {
      console.log('Can\'t get cookie! Check the name!');
    }
});

So now you don't need content script for this but don't forget to include permissions into manifest:

"permissions": [
  "cookies",
  "*://*.example.com/*"
]