# \#learning

**URL:** https://discourse.mozilla.org/tag/learning/26.md

[Latest](https://discourse.mozilla.org/latest.md) · [Categories](https://discourse.mozilla.org/categories.md) · [Tags](https://discourse.mozilla.org/tags.md)

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## [Beginner MDN curriculum CSS example not working in Firefox 158.0 (64-bit)](https://discourse.mozilla.org/t/beginner-mdn-curriculum-css-example-not-working-in-firefox-158-0-64-bit/149837)

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**Author:** [@schooldude777](https://discourse.mozilla.org/u/schooldude777)\
**Replies:** 2\
**Last updated:** [October 19, 2026, 1:47pm UTC](https://discourse.mozilla.org/t/beginner-mdn-curriculum-css-example-not-working-in-firefox-158-0-64-bit/149837 "2026-10-19T13:47:49Z")

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Hello, I’m currently at the section “Getting started with CSS” where they teach about at-rules. I’m trying the following code example: @media (width \< 550px) { body { background-color: rgb(179, 255, 0); } } @…

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## [Beginner JavaScript question from MDN curriculum](https://discourse.mozilla.org/t/beginner-javascript-question-from-mdn-curriculum/149802)

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**Author:** [@schooldude777](https://discourse.mozilla.org/u/schooldude777)\
**Replies:** 5\
**Last updated:** [October 17, 2026, 5:02pm UTC](https://discourse.mozilla.org/t/beginner-javascript-question-from-mdn-curriculum/149802 "2026-10-17T17:02:27Z")

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Hello! I’m new to JavaScript and I’m following the MDN curriculum and I’m currently in JavaScript: Adding interactivity section. Here is what I don’t fully understand. Code below: const listItems = document.querySelec…

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## [Mozilla Firefox Addon](https://discourse.mozilla.org/t/mozilla-firefox-addon/29355)

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**Author:** [@pbjsowon408](https://discourse.mozilla.org/u/pbjsowon408)\
**Replies:** 2\
**Last updated:** [October 14, 2026, 3:34pm UTC](https://discourse.mozilla.org/t/mozilla-firefox-addon/29355 "2026-10-14T15:34:43Z")

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Is there theme changing addon for various colors? Addons that exists in the firefox are only providing the simple colors such as black and white.

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## [Kamal Hinduja : Where do I file bug reports about Discourse?](https://discourse.mozilla.org/t/kamal-hinduja-where-do-i-file-bug-reports-about-discourse/146169)

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**Author:** [@Kamal\_Hinduja](https://discourse.mozilla.org/u/Kamal_Hinduja)\
**Replies:** 1\
**Last updated:** [October 14, 2026, 2:19pm UTC](https://discourse.mozilla.org/t/kamal-hinduja-where-do-i-file-bug-reports-about-discourse/146169 "2026-10-14T14:19:36Z")

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Hi, I am Kamal Hinduja based Geneva, Switzerland(Swiss). Can anyone explain where I should file bug reports about Discourse? Thanks, Regards Kamal Hinduja Geneva, Switzerland

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## [Clarification on the use of "primitive type" vs "primitive value" in JavaScript](https://discourse.mozilla.org/t/clarification-on-the-use-of-primitive-type-vs-primitive-value-in-javascript/147042)

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**Author:** [@Andriy\_Ovcharov](https://discourse.mozilla.org/u/Andriy_Ovcharov)\
**Replies:** 1\
**Last updated:** [October 14, 2026, 12:34pm UTC](https://discourse.mozilla.org/t/clarification-on-the-use-of-primitive-type-vs-primitive-value-in-javascript/147042 "2026-10-14T12:34:58Z")

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Dear MDN / Mozilla team, I hope this message finds you well. I am seeking clarification regarding terminology used in JavaScript documentation and the ECMAScript specification. Specifically, I want to understand the re…

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## [When publishing a theme, Firefox says the theme is corrupt](https://discourse.mozilla.org/t/when-publishing-a-theme-firefox-says-the-theme-is-corrupt/137651)

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**Author:** [@Shastarocks](https://discourse.mozilla.org/u/Shastarocks)\
**Replies:** 2\
**Last updated:** [October 5, 2026, 3:18pm UTC](https://discourse.mozilla.org/t/when-publishing-a-theme-firefox-says-the-theme-is-corrupt/137651 "2026-10-05T15:18:03Z")

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I am trying to put together a theme for Firefox, and when I publish the theme and try to download the .zip or install it from the page, I get an error message that reads: “Installation aborted because the add-on appears …

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## [Policy clarification: embedding user-selected websites in an extension page](https://discourse.mozilla.org/t/policy-clarification-embedding-user-selected-websites-in-an-extension-page/149604)

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**Author:** [@mike.dev.t](https://discourse.mozilla.org/u/mike.dev.t)\
**Replies:** 0\
**Last updated:** [September 27, 2026, 7:41pm UTC](https://discourse.mozilla.org/t/policy-clarification-embedding-user-selected-websites-in-an-extension-page/149604 "2026-09-27T19:41:01Z")

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Would Mozilla consider an exception to the security-header policy for an extension that embeds user-selected websites within its own locally packaged page? The proposed behavior would remove X-Frame-Options and CSP fram…

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## [Firefox font rendering issues](https://discourse.mozilla.org/t/firefox-font-rendering-issues/149244)

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**Author:** [@Zats-a-Sour](https://discourse.mozilla.org/u/Zats-a-Sour)\
**Replies:** 0\
**Last updated:** [August 22, 2026, 9:51pm UTC](https://discourse.mozilla.org/t/firefox-font-rendering-issues/149244 "2026-08-22T21:51:58Z")

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Im developing a personal project that uses the comic sans font(and some other microsoft fonts) in combination with a lack of anti-aliasing in order to make the text look like a really old website. While it works fine on …

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## [What does the path to Recommended actually look like for an AI extension?](https://discourse.mozilla.org/t/what-does-the-path-to-recommended-actually-look-like-for-an-ai-extension/149026)

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**Author:** [@Emre\_Sokullu](https://discourse.mozilla.org/u/Emre_Sokullu)\
**Replies:** 2\
**Last updated:** [July 24, 2026, 7:03pm UTC](https://discourse.mozilla.org/t/what-does-the-path-to-recommended-actually-look-like-for-an-ai-extension/149026 "2026-07-24T19:03:12Z")

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Hi all, I maintain WebBrain, an open-source (MIT) AI browser agent for Firefox. It reads pages, extracts data, and automates browser tasks using a model of the user’s choice, and it can run fully local via llama.cpp or …

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## [Tạo theme xong rồi thì khi nào theme tôi mới được duyệt](https://discourse.mozilla.org/t/t-o-theme-xong-r-i-thi-khi-nao-theme-toi-m-i-d-c-duy-t/149004)

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**Author:** [@Victor\_NVS](https://discourse.mozilla.org/u/Victor_NVS)\
**Replies:** 1\
**Last updated:** [July 21, 2026, 10:40am UTC](https://discourse.mozilla.org/t/t-o-theme-xong-r-i-thi-khi-nao-theme-toi-m-i-d-c-duy-t/149004 "2026-07-21T10:40:00Z")

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Tôi có tạo theme xong và upload lên nhưng đến giờ vẫn chưa thấy duyệt theme. Khi nào tôi mới nhận phản hồi

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## [Soon it is brand new Mozilla SI Browser just for starts. Unbeliveable features made by RED (Harri Ikonen)](https://discourse.mozilla.org/t/soon-it-is-brand-new-mozilla-si-browser-just-for-starts-unbeliveable-features-made-by-red-harri-ikonen/148828)

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**Author:** [@Harri\_Ikonen](https://discourse.mozilla.org/u/Harri_Ikonen)\
**Replies:** 1\
**Last updated:** [July 21, 2026, 1:24am UTC](https://discourse.mozilla.org/t/soon-it-is-brand-new-mozilla-si-browser-just-for-starts-unbeliveable-features-made-by-red-harri-ikonen/148828 "2026-07-21T01:24:55Z")

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Tämä “lisäosa” tai siis koko selain tulee olemaan jotain uskomatonta. Kehitämme kokonaan aivan uudenlaisen selaimen, johon tulee uskomattomia helpotuksia, jolloin saattaa tulla mieleen, että tarvitseeko tässä tehdä enää …

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## [Is it possible to modify the context menu display name for a dictionary?](https://discourse.mozilla.org/t/is-it-possible-to-modify-the-context-menu-display-name-for-a-dictionary/148990)

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**Author:** [@dcooper\_mozillaid](https://discourse.mozilla.org/u/dcooper_mozillaid)\
**Replies:** 0\
**Last updated:** [July 19, 2026, 8:02pm UTC](https://discourse.mozilla.org/t/is-it-possible-to-modify-the-context-menu-display-name-for-a-dictionary/148990 "2026-07-19T20:02:34Z")

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I have been trying to develop a custom Firefox dictionary add-on that bundles multiple distinct botanical word lists into a single extension using Manifest V3. My manifest.json defines the dictionaries like this: “dict…

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## [How to create a theme that can alter most of the colours in thunderbird](https://discourse.mozilla.org/t/how-to-create-a-theme-that-can-alter-most-of-the-colours-in-thunderbird/138007)

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**Author:** [@Dove](https://discourse.mozilla.org/u/Dove)\
**Replies:** 1\
**Last updated:** [June 17, 2026, 9:16am UTC](https://discourse.mozilla.org/t/how-to-create-a-theme-that-can-alter-most-of-the-colours-in-thunderbird/138007 "2026-06-17T09:16:07Z")

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Hi, I would like to create a theme for thunderbird that can change more than just the tab and frame colour, ideally I would like to be able to change the background, sidebar and text colour aswell. I have managed to ge…

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## [hiding title bar in FireFox](https://discourse.mozilla.org/t/hiding-title-bar-in-firefox/148539)

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**Author:** [@testing\_maybebug](https://discourse.mozilla.org/u/testing_maybebug)\
**Replies:** 1\
**Last updated:** [June 1, 2026, 12:04pm UTC](https://discourse.mozilla.org/t/hiding-title-bar-in-firefox/148539 "2026-06-01T12:04:14Z")

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Hello, not long ago I’ve discovered the news about ditching the XUL -based Add-ons for FF in favor of WebExtensions. That sounds nice, but I’m afraid, that by looking and the WE possibilities some addon’s won’t be able …

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## [\[Showcase\] Building a Global Media Controller for Firefox (Proof-of-Concept)](https://discourse.mozilla.org/t/showcase-building-a-global-media-controller-for-firefox-proof-of-concept/148406)

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**Author:** [@MK2010GAMER](https://discourse.mozilla.org/u/MK2010GAMER)\
**Replies:** 2\
**Last updated:** [May 23, 2026, 2:51am UTC](https://discourse.mozilla.org/t/showcase-building-a-global-media-controller-for-firefox-proof-of-concept/148406 "2026-05-23T02:51:09Z")

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I’ve developed a lightweight extension to add a feature that Firefox currently completely lacks: a native, global media controller. The Problem: Firefox has no centralized, global UI for users to view or control media p…

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## [All the tabs I had saved in Tab Session Manager disappeared](https://discourse.mozilla.org/t/all-the-tabs-i-had-saved-in-tab-session-manager-disappeared/148225)

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**Author:** [@yonofu123](https://discourse.mozilla.org/u/yonofu123)\
**Replies:** 3\
**Last updated:** [May 12, 2026, 12:51am UTC](https://discourse.mozilla.org/t/all-the-tabs-i-had-saved-in-tab-session-manager-disappeared/148225 "2026-05-12T00:51:58Z")

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When I put my PC to sleep, my Firefox add-ons disappeared and stopped showing up, and I was automatically logged out of the sites I was logged into. After that, Tab Session Manager showed an error saying it was corrupte…

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## [New Developer Looking for Best Practices for Building and Security Local Network](https://discourse.mozilla.org/t/new-developer-looking-for-best-practices-for-building-and-security-local-network/148249)

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**Author:** [@MadelineStrong](https://discourse.mozilla.org/u/MadelineStrong)\
**Replies:** 0\
**Last updated:** [May 9, 2026, 10:26am UTC](https://discourse.mozilla.org/t/new-developer-looking-for-best-practices-for-building-and-security-local-network/148249 "2026-05-09T10:26:24Z")

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Hello developers! I am new to your community on the learning track and ready to move further into AI development, coding, continue app development and packaging. I knew I needed a local network development setup for tes…

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## [Problem with internationalisation management](https://discourse.mozilla.org/t/problem-with-internationalisation-management/148219)

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**Author:** [@wronschien](https://discourse.mozilla.org/u/wronschien)\
**Replies:** 10\
**Last updated:** [May 6, 2026, 8:55am UTC](https://discourse.mozilla.org/t/problem-with-internationalisation-management/148219 "2026-05-06T08:55:10Z")

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This is a copy of a post I made on reddit r/FirefoxAddons/, I’ve been advised to also post here so here we go. Being fairly new to development, I made a test addon with a background script containing a non-ascii charact…

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## [Web development tool in mozzila](https://discourse.mozilla.org/t/web-development-tool-in-mozzila/147532)

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**Author:** [@urururuuu](https://discourse.mozilla.org/u/urururuuu)\
**Replies:** 1\
**Last updated:** [April 20, 2026, 11:33am UTC](https://discourse.mozilla.org/t/web-development-tool-in-mozzila/147532 "2026-04-20T11:33:29Z")

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hello everyone! I am interested in the question of how, using the web development tool firefox, you can like the YouTube channel for video, through the web development tool

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## [Borderify Extension not working (no errors)](https://discourse.mozilla.org/t/borderify-extension-not-working-no-errors/53768)

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**Author:** [@Calador](https://discourse.mozilla.org/u/Calador)\
**Replies:** 9\
**Last updated:** [February 14, 2026, 8:37am UTC](https://discourse.mozilla.org/t/borderify-extension-not-working-no-errors/53768 "2026-02-14T08:37:09Z")

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Hi, I’m working on the Borderify Tutorial. What I made: Cloned the github source code Uploaded the Plugin (clicked on the manifest.json) Opened developer.mozilla.org No red border Appeared No errors are thrown Sad…

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## [How long does it take for a add-on AMO to get approved?](https://discourse.mozilla.org/t/how-long-does-it-take-for-a-add-on-amo-to-get-approved/147393)

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**Author:** [@Varshit\_Nunna](https://discourse.mozilla.org/u/Varshit_Nunna)\
**Replies:** 1\
**Last updated:** [February 11, 2026, 5:12pm UTC](https://discourse.mozilla.org/t/how-long-does-it-take-for-a-add-on-amo-to-get-approved/147393 "2026-02-11T17:12:59Z")

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I have uploaded my New tab extention about 24 hrs ago and it hasnt been approved yet???

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## [Account access for review](https://discourse.mozilla.org/t/account-access-for-review/147358)

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**Author:** [@Niels\_Creces](https://discourse.mozilla.org/u/Niels_Creces)\
**Replies:** 1\
**Last updated:** [February 11, 2026, 5:52am UTC](https://discourse.mozilla.org/t/account-access-for-review/147358 "2026-02-11T05:52:55Z")

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Hey, i made an add-on for internal company usage, it helps the people to quickly scan tikcet for potential issue, and other “power user” options. but its on a site “autotask” which contains significant mount of sensiti…

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## [Is there a way to stream in-memory data into downloads.download?](https://discourse.mozilla.org/t/is-there-a-way-to-stream-in-memory-data-into-downloads-download/147383)

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**Author:** [@Phob](https://discourse.mozilla.org/u/Phob)\
**Replies:** 0\
**Last updated:** [February 9, 2026, 2:24pm UTC](https://discourse.mozilla.org/t/is-there-a-way-to-stream-in-memory-data-into-downloads-download/147383 "2026-02-09T14:24:42Z")

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Hello, I am writing an extension, which modifies certain download requests by splitting them into several smaller requests and stitching the responses together, then pushing the resulting data into the downloads.download…

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## [Why does runtime.onSuspend not execute window.localStorage.setItem?](https://discourse.mozilla.org/t/why-does-runtime-onsuspend-not-execute-window-localstorage-setitem/147206)

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**Author:** [@Foxreef](https://discourse.mozilla.org/u/Foxreef)\
**Replies:** 2\
**Last updated:** [January 19, 2026, 4:22pm UTC](https://discourse.mozilla.org/t/why-does-runtime-onsuspend-not-execute-window-localstorage-setitem/147206 "2026-01-19T16:22:24Z")

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I am coding my first extension right now and I wanted to save a value before the browser closes. I, at first, tried to use browser.runtime.onSuspend.addListener() : browser.runtime.onSuspend.addListener(() =\> { window.…

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## [How to create geckoview FAT AAR?](https://discourse.mozilla.org/t/how-to-create-geckoview-fat-aar/136743)

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**Author:** [@devel2ew](https://discourse.mozilla.org/u/devel2ew)\
**Replies:** 3\
**Last updated:** [January 18, 2026, 12:57pm UTC](https://discourse.mozilla.org/t/how-to-create-geckoview-fat-aar/136743 "2026-01-18T12:57:50Z")

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How to create FAT AAR with multiple architectures? AAR and POM files are included (released build). Firefox 131 source. root@9e6bfae6b70f:/firefox/mozilla-unified# ./mach configure --disable-compile-environment --en…

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## [An estimate is required for the structuring of planet data](https://discourse.mozilla.org/t/an-estimate-is-required-for-the-structuring-of-planet-data/147055)

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**Author:** [@20skoropad03](https://discourse.mozilla.org/u/20skoropad03)\
**Replies:** 0\
**Last updated:** [January 3, 2026, 9:56pm UTC](https://discourse.mozilla.org/t/an-estimate-is-required-for-the-structuring-of-planet-data/147055 "2026-01-03T21:56:23Z")

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Rate my work please https://codepen.io/eKa-the-vuer/pen/ZYGgyBJ

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## [How do I debug Firefox on iOS?](https://discourse.mozilla.org/t/how-do-i-debug-firefox-on-ios/111414)

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**Author:** [@dioptre](https://discourse.mozilla.org/u/dioptre)\
**Replies:** 7\
**Last updated:** [January 3, 2026, 9:52pm UTC](https://discourse.mozilla.org/t/how-do-i-debug-firefox-on-ios/111414 "2026-01-03T21:52:17Z")

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I tried debugging using safari, and a weird error occurs that if the safari debugger is attached the site renders differently, so want to do the same with firefox. I’ve looked at the documentation, and it only shows how…

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## [How i can check variable for non-empty in selector?](https://discourse.mozilla.org/t/how-i-can-check-variable-for-non-empty-in-selector/90181)

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**Author:** [@DenF](https://discourse.mozilla.org/u/DenF)\
**Replies:** 2\
**Last updated:** [January 3, 2026, 9:37pm UTC](https://discourse.mozilla.org/t/how-i-can-check-variable-for-non-empty-in-selector/90181 "2026-01-03T21:37:20Z")

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How i can check random $variable for non-empty/existing? What about if variable will not passed from application? For example, random .ftl file: that\_string = { $username -\> \[what i need to pass there?\] …

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## [Insert text into textbox with add-on click](https://discourse.mozilla.org/t/insert-text-into-textbox-with-add-on-click/146695)

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**Author:** [@UncannyMachines](https://discourse.mozilla.org/u/UncannyMachines)\
**Replies:** 2\
**Last updated:** [December 15, 2025, 10:02pm UTC](https://discourse.mozilla.org/t/insert-text-into-textbox-with-add-on-click/146695 "2025-12-15T22:02:45Z")

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I’m new to making Firefox plugins (and to JavaScript). I’ve been following the tutorials, but want to do something a little different. I’d like to insert a string of text into the focused element of a webpage when the us…

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## [How to create a unified starred folder?](https://discourse.mozilla.org/t/how-to-create-a-unified-starred-folder/135400)

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**Author:** [@rokejulianlockhart](https://discourse.mozilla.org/u/rokejulianlockhart)\
**Replies:** 3\
**Last updated:** [December 11, 2025, 11:33am UTC](https://discourse.mozilla.org/t/how-to-create-a-unified-starred-folder/135400 "2025-12-11T11:33:43Z")

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I’d like a unified folder for my starred messages. There isn’t an automatically generated folder or tag. Ideally, there should be, but I’d like to ascertain whether a workaround exists (before I file a ticket at Bugzilla…

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