Struct LogTemplate 

pub struct LogTemplate {
    pub info: Option<String>,
    pub debug: Option<String>,
    pub trace: Option<String>,
}

Log template for generating log messages from event/action data

Templates use {field} syntax to interpolate values from JSON data. Each level (info/debug/trace) can have its own template format.

Example

let template = LogTemplate::new()
    .with_info("{client_ip} {method} {path} -> {status}")
    .with_debug("HTTP {method} {path} from {client_ip}:{client_port}")
    .with_trace("HTTP request: {json_pretty(.)}");

Fields

info: Option<String>

INFO level: One-liner access log style (protocol-specific) Example: “{client_ip} {method} {path} -> {status} ({response_bytes}B, {duration_ms}ms)”

debug: Option<String>

DEBUG level: Extra details + timing Example: “HTTP {method} {path} from {client_ip}:{client_port}, headers: {headers_len}”

trace: Option<String>

TRACE level: Full request/response details Example: “Full HTTP request: {json_pretty(.)}”

Implementations

impl LogTemplate

pub fn new() -> Self

Create a new empty log template

pub fn with_info(self, template: impl Into<String>) -> Self

Set INFO level template

Used for one-liner access log style messages. Example: “{client_ip} {method} {path} -> {status}”

pub fn with_debug(self, template: impl Into<String>) -> Self

Set DEBUG level template

Used for extra details including timing. Example: “HTTP {method} {path} from {client_ip}:{client_port}”

pub fn with_trace(self, template: impl Into<String>) -> Self

Set TRACE level template

Used for full payload details. Example: “Full request: {json_pretty(.)}”

pub fn get_template(&self, level: LogLevel) -> Option<&str>

Get the template string for a given log level

pub fn render(&self, level: LogLevel, data: &Value) -> Option<String>

Render the template for a given log level with event/action data

Returns None if no template is defined for the level.

Arguments

• level - The log level to render
• data - JSON data to interpolate into the template

Template Syntax

• {field} - Simple field access
• {field.subfield} - Nested field access (dot notation)
• {json(field)} - Compact JSON of field
• {json_pretty(.)} - Pretty-print entire data object
• {hex(field)} - Hex-encode string field
• {field_len} - Length of array/string/object field
• {preview(field)} - First 100 chars with ellipsis
• {preview(field,50)} - First N chars with ellipsis

pub fn has_any(&self) -> bool

Check if any template is defined

Trait Implementations

impl Clone for LogTemplate

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LogTemplate

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LogTemplate

fn default() -> Self

Returns the “default value” for a type.