Format-json

Render a Record into compact JSON text. This helper is the direct structured-output path used by JSON-oriented logging workflows when you want machine-readable serialization without building a sink.

Interface

pub fn format_json(rec : Record) -> String {

input

• rec : Record - Log record to serialize.

output

• String - Compact JSON text built from the record contents.

Explanation

Detailed rules explaining key parameters and behaviors

• The output always includes level, message, and fields.
• timestamp_ms is only included when rec.timestamp_ms != 0.
• target is only included when rec.target is not empty.
• The result is compact JSON text rather than pretty-printed output.
• Field values are serialized through the record's structured field array instead of reparsing formatted text.

How to Use

Here are some specific examples provided.

When Need Machine-readable Output In Tests Or Adapters

When record data should be passed along as structured JSON text:

let rec = Record::new(Level::Info, "ready", fields=[field("service", "api")])
println(format_json(rec))

In this example, the returned string can be consumed by JSON-aware tooling.

When Need Structured Output Without A Json Sink Instance

When a callback or bridge already has a Record and only needs serialization:

let callback = fn(rec : Record) {
  let payload = format_json(rec)
  println(payload)
}

In this example, the code reuses the built-in JSON record shape directly.

Error Case

e.g.:

• There is no separate failure path for valid Record values.

• If a caller needs readable aligned text rather than JSON, format_text(...) is the better API.

Notes

1. This helper returns compact JSON and does not expose a pretty-print option.

2. It is a natural companion to json_console_sink() for structured logging flows.