This allows to configure the last (and often only) flow on creation of
the Logger without having to manually create the object. We can thus use
the following shortcut to e.g. set a custom encoder:
Rackstash::Logger.new(STDOUT) do
encoder Rackstash::Encoder::Message.new
end
That way, we ensure that the error_flow receives an expected event and
doesn;t have to deal with different data formats which might result in
additional (then quietly hidden) errors.
The encoder is then responsible to format it as it pleases. Commonly,
encoders can use Rackstash::Encoders::Helpers::Message#normalize_message
to create a single combined message string.
If the encoder is not interested in using the message, it can jsut get
rid if it without incuring any overhead.
With the change to allow ading fields to the Buffer with a Logger
interface in the previous commit, we should also flush those Buffers
with fields set that way by default.
With this interface, the user adds fields the same way they would add
messages. The implicit assumption here is that the buffer is handled the
same way. Thus, if the current buffer is non-buffering, we will
automatically flush it to the sink and clear it, just the same way as we
would have done it for a message.
This new name better reflects what this option actually does: it allows
to flush a Buffer even if there were just added fields or tags. A tryely
empty Buffer, i.e., one which has neither added messages, fields, or
tags is never flushed.
This field is only relevant when actually sending JSON to Logstash.
Other formats don't need it. It is thus more desireable to only include
this field in a specific logstash JSON encoder.
It is not universally useful to enfore a single assignment mode. With
short conditionals (or even a ternary operator), an assignment of the
returned value is common. For longer or more complex conditionals, I
perfer an assignment inside the condition to decouple the conditional
checks from the assignment logic.
