1698840 - Facebook embedded posts are not displayed on eventbrite.com with ETP - Strict enabled

Status: NEW

(Web Compatibility :: Privacy: Site Reports, defect, P3)

Description

[Oana Arbuzov [:oanaarbuzov]]

Attachment: StrictVsStandard.png

Environment:
Browser / Version: Firefox Nightly 210315 (🦎 88.0a1-20210313094300)
Operating System: Samsung Galaxy S8 (Android 9) - 1440 x 2960 pixels, 18.5:9 ratio (~570 ppi density), Google Pixel 5 (Android 11) - 1080 x 2340 pixels, 19.5:9 ratio (~432 ppi density)

Prerequisites:
ETP - Strict enabled.

Steps to reproduce:

1. Navigate to https://www.eventbrite.com/o/tokyo-coding-club-27361767969
2. Scroll down the page to Facebook section.
3. Observe the page.

Expected Behavior:
Facebook embedded posts are displayed.

Actual Behavior:
Facebook embedded posts are not displayed.

Notes:

1. Screenshot attached.
2. The issue is not reproducible with ETP - Standard.

Comment 1

[Negritas Sergiu, Desktop QA]

Hello! This issue does not reproduce with firefox 88.0a1(2021-03-16) and 139.0a1(2025-04-11) on Ubuntu 22.04 and Windows 10.

Comment 2

[Raul Bucata]

I guess the page had a UI update, as I can not see any embedded Facebook posts, for valid events. Sergiu, is there a specific link or event that shows embedded Facebook posts?

Comment 3

[Negritas Sergiu, Desktop QA]

Hello Raul!
I don't know if there is maybe the website changed in all this time. I just followed the steps from the description in order to reproduce it.

Comment 4

[James Han]

Attachment: Bug 1698840 - Add support for Facebook embedded posts (fb-post) in Facebook SDK shim. r?manuel

When ETP-Strict is enabled, Facebook embedded posts using the fb-post
XFBML element are blocked and not displayed. This patch extends the
Facebook SDK shim to detect fb-post elements and render placeholders
that users can click to opt-in to loading the real Facebook content.

Changes:

• Added makePostPlaceholder() function to render styled placeholders
  for fb-post elements with Facebook logo and clear messaging
• Updated MutationObserver to detect dynamically-added fb-post elements
• Updated FB.XFBML.parse() to process fb-post elements on page load
• Added test HTML file to verify the fix works with static, dynamic,
  and custom-width post embeds

Comment 5

[Manuel Bucher [:manuel] {{ FYI: OOO Jul 30 - Aug 16 }}]

Unassigning, because the facebook smartblock shim should be handled in a new bug within the Firefox :: Privacy: Anti-Tracking component as mentioned in the review D275716#9554019.