# `Honeybadger.Filter.Mixin`
[🔗](https://github.com/honeybadger-io/honeybadger-elixir/blob/v0.30.1/lib/honeybadger/filter/mixin.ex#L1)

A default implementation of `Honeybadger.Filter`.

If you need to implement custom filtering for one or more of the elements in
a `Honeybadger.Notice`, you can define your own filter module and register it
in the config.  E.g., if you wanted to filter the error message string, but
keep all of the other default filtering, you could do:

    defmodule MyApp.MyFilter do
      use Honeybadger.Filter.Mixin

      def filter_error_message(message) do
        # replace passwords in error message with `"xxx"`
        Regex.replace(~r/(password: *)"([^"]+)"/, message, ~s(\1"xxx"))
      end
    end

And set the configuration to:

    config :honeybadger,
      filter: MyApp.MyFilter

See the documentation for `Honeybadger.Filter` for a list of functions that
may be overridden.  The default implementations for all of the functions that
take a `map` are to remove any keys from the map that match a key in
`filter_keys`. The check matches atoms and strings in a case insensitive
manner.

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*Consult [api-reference.md](api-reference.md) for complete listing*