Harlock.Sub.Logger (harlock v0.6.0)

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:logger handler behind Harlock.Sub.logger/1, plus the helper for turning a delivered entry into text.

The subscription delivers entries as maps:

%{level: :warning, msg: raw_msg, meta: metadata}

msg is Erlang's raw message term — {:string, chardata}, {:report, map}, or a {format, args} pair. It arrives unformatted on purpose: formatting allocates, and a log handler runs inside the process that called Logger.warning/1, so formatting there bills the caller for your UI. Call text/1 from update/2 instead, where the cost lands on the runtime:

def update({:log, entry}, m) do
  line = Harlock.Sub.Logger.text(entry)
  %{m | lines: [line | m.lines]}
end

Summary

Types

entry()

A delivered log entry: the level, Erlang's raw message term, and metadata.

Functions

text(other)

Render a delivered entry's message as a binary.

Types

entry()

@type entry() :: %{level: :logger.level(), msg: term(), meta: map()}

A delivered log entry: the level, Erlang's raw message term, and metadata.

Functions

text(other)

@spec text(entry() | term()) :: String.t()

Render a delivered entry's message as a binary.

Handles all three shapes Erlang's :logger produces: {:string, chardata}, {:report, term}, and {format, args}. Call this on the runtime side rather than in a transform — a transform runs in the process that logged.