$ the-wire · showcase
KEYWORD OPERATIONS GET 15% FASTER, LIVE NAVIGATION EVENT BUG SEALED
By RepoJournal · Filed · About Elixir & Phoenix · Composed from the cited sources · methodology
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Elixir core eliminates redundant list traversals in Keyword.pop while Phoenix LiveView closes a race condition where old view events leak into new views during navigation.
The Keyword module saw a meaningful optimization land in core [1]: pop/3, pop!/2, and pop_lazy/3 now execute in 2 list traversals instead of 3 by calling :lists.keyfind and delete_key directly rather than chaining fetch and delete. The benchmark shows ~1.15x speedup on average. This is the kind of foundational polish that compounds across thousands of applications. Meanwhile, Phoenix LiveView fixed a subtle but real race condition [2] where old DOM could still render during phx-remove transitions while the view registry already pointed to the new view, causing events to reach the wrong lifecycle. The fix switches owner lookup from ID-based to private view marker-based tracking. On the documentation front, Phoenix updated requirement blockquotes to use ExDoc admonitions for cleaner rendering [3], and LiveView's security guide now explicitly emphasizes never trusting user input in params and payloads [4]. A smaller cleanup removed unreachable dead code in LiveView's change tracking [5].
Action items
- → Review LiveView applications for phx-remove transitions paired with live_navigation to ensure event leakage is not a factor in your use case phoenixframework/phoenix_live_view [plan]
- → Read the updated LiveView security guide, particularly the 'Never trust user input' section on params and payloads phoenixframework/phoenix_live_view [monitor]
- → Benchmark Keyword.pop operations in production if you rely heavily on keyword argument handling elixir-lang/elixir [monitor]
References
- [1] Optimize Keyword.pop/3, pop!/2, and pop_lazy/3 (#15466) ↗ elixir-lang/elixir
- [2] When navigating, prevent outdated events from reaching the new view ↗ phoenixframework/phoenix_live_view
- [3] Update requirement blockquotes to use ExDoc admonitions ↗ phoenixframework/phoenix
- [4] Improve security guide regarding user input ↗ phoenixframework/phoenix_live_view
- [5] Remove dead vars_changed_vars(:all) clause (#4294) ↗ phoenixframework/phoenix_live_view
