mirror of
https://github.com/Nanaloveyuki/BitLogger.git
synced 2026-07-24 08:52:35 +00:00
Nanaloveyuki
82 lines
2.8 KiB
Markdown
82 lines
2.8 KiB
Markdown
---
|
|
name: formatted-callback-sink
|
|
group: api
|
|
category: sink
|
|
update-time: 20260613
|
|
description: Create a callback sink from a low-level RecordFormatter function and string callback.
|
|
key-word:
|
|
- sink
|
|
- callback
|
|
- formatter
|
|
- public
|
|
---
|
|
|
|
## Formatted-callback-sink
|
|
|
|
Create a callback sink from a `RecordFormatter` and a string callback. This is the low-level text-delivery constructor for integrations that already have custom record-to-string formatting logic and want the final rendered text in a callback.
|
|
|
|
### Interface
|
|
|
|
```moonbit
|
|
pub fn formatted_callback_sink(
|
|
formatter : RecordFormatter,
|
|
callback : (String) -> Unit,
|
|
) -> FormattedCallbackSink {
|
|
```
|
|
|
|
#### input
|
|
|
|
- `formatter : RecordFormatter` - Function used to render each record into a final string.
|
|
- `callback : (String) -> Unit` - Function receiving the rendered string.
|
|
|
|
#### output
|
|
|
|
- `FormattedCallbackSink` - Callback sink that forwards formatter output as text.
|
|
|
|
### Explanation
|
|
|
|
Detailed rules explaining key parameters and behaviors
|
|
|
|
- This helper stores both the provided formatter and callback directly inside the sink.
|
|
- The callback receives exactly the string returned by the formatter.
|
|
- It is lower-level than `text_callback_sink(...)` because it works with arbitrary `RecordFormatter` functions instead of `TextFormatter` values.
|
|
- Use it when formatting logic is already expressed as code rather than formatter configuration data.
|
|
|
|
### How to Use
|
|
|
|
Here are some specific examples provided.
|
|
|
|
#### When Need Custom Rendered Text In A Callback Integration
|
|
|
|
When an adapter should receive a hand-formatted line instead of a structured record:
|
|
```moonbit
|
|
let formatter : RecordFormatter = fn(rec) { "[" + rec.level.label() + "] " + rec.message }
|
|
let sink = formatted_callback_sink(formatter, fn(line) { println(line) })
|
|
```
|
|
|
|
In this example, the callback receives exactly the custom rendered text.
|
|
|
|
#### When Already Working With Shared RecordFormatter Values
|
|
|
|
When formatter creation already happened elsewhere and should be reused directly:
|
|
```moonbit
|
|
fn make_sink(formatter : RecordFormatter) -> FormattedCallbackSink {
|
|
formatted_callback_sink(formatter, fn(line) { println(line) })
|
|
}
|
|
```
|
|
|
|
In this example, the low-level sink constructor keeps the integration in terms of formatter functions and final text callbacks.
|
|
|
|
### Error Case
|
|
|
|
e.g.:
|
|
- If structured field access is required inside the callback, `callback_sink(...)` is the better API because it forwards full `Record` values.
|
|
|
|
- If a configurable text formatting policy is preferred over a code-defined function, `text_callback_sink(...)` is usually the better API.
|
|
|
|
### Notes
|
|
|
|
1. Use this helper when the formatter is already a `RecordFormatter` and the destination expects final text.
|
|
|
|
2. Use `text_callback_sink(...)` when the source formatting policy is a `TextFormatter` value.
|