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Can not get cookie after set by using document.cookie on firefox 57

  • 6 replies
  • 1 has this problem
  • Last reply by Tam Vo

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Hi, I'm writing a web extension and when I opened extension debugging mode through "about debugging".

From console tab, I type "document.cookie = "username=tam;expires=Mon, 23 Feb 2018 17:35:38 GMT;path=/";" and Enter to set cookie. But after set, I type "document.cookie" it return empty string.

And my extension can not set or get cookie from document.cookie

I don't know what happen with cookie that I set.

Attached screenshots

Modified by Tam Vo

All Replies (6)

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Post your question in the add-ons forum;

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I posted on and hope someone will answer it. Thanks.

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Does it work if you leave a space after the colons?

  • document.cookie = "username=tam; expires=Mon, 23 Feb 2018 17:35:38 GMT; path=/";
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It's still not working.

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I see the username=tam cookie in the Storage Inspector and also in document.cookie.

Make sure you do not run Firefox in permanent Private Browsing mode (Always use Private Browsing mode; Never Remember History) in case that makes a difference.

  • Options/Preferences -> Privacy & Security -> Firefox will: "Use custom settings for history"
  • remove checkmark: [ ] "Always use Private Browsing mode"

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

  • switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
  • do NOT click the "Refresh Firefox" button on the Safe Mode start window
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I setup with your suggestion. In developer tools for web extension, I can not get cookie after set. On developer tool on web I can set and get it. See attachment below.