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When collapsed threads is enabled, notifications behave differently - see matrix of scenarios and associated outputs here (full spreadsheet of the chart below)
Desktop Notifications
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When a user receives notifications about a root post - no change to existing flow. Take the user to the channel, scrolled to the root post
When a user receives notifications about a reply post in a thread that is followed, take the user to the thread in the Global Threads context
When a user receives notifications about a reply post in a thread that is not followed, take the user to the thread in the Channel context (RHS)
Mobile Notifications
When a user receives notifications about a root post - no change to existing flow. Take the user to the channel, scrolled to the root post
When a user receives notifications about a reply post in a thread that is followed, take the user to the thread in the Global Threads context
When a user receives notifications about a reply post in a thread that is not followed (for cases when notifications are turned on for all activity), take the user to the thread in the Channel context (RHS)
Notification Stacks in Notification Center:
Root posts are stacked by channel
Reply posts are stacked by thread
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Channel vs. Threads badges
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