Struct FrontmatterParser 

pub struct FrontmatterParser { /* private fields */ }

Unified frontmatter parser with templating support.

This struct provides a centralized interface for parsing frontmatter from content using the grey_matter library, with optional Tera templating support. It handles YAML, TOML, and JSON frontmatter formats automatically.

Implementations

impl FrontmatterParser

pub fn new() -> Self

Create a new frontmatter parser.

pub fn with_project_dir(project_dir: PathBuf) -> Result<Self>

Create a new frontmatter parser with custom project directory.

Arguments

• project_dir - Project root directory for template rendering

pub fn parse_with_templating<T>( &mut self, content: &str, variant_inputs: Option<&Value>, file_path: &Path, context: Option<&OperationContext>, ) -> Result<ParsedFrontmatter<T>>

where T: DeserializeOwned,

Parse content and extract frontmatter with optional templating.

This method provides the complete parsing pipeline:

1. Extract frontmatter using gray_matter
2. Apply Tera templating if variant_inputs is provided
3. Deserialize the result to the target type

Arguments

• content - The content to parse
• variant_inputs - Optional template variables (project, config, etc.)
• file_path - Path to the file (used for error reporting)
• context - Optional operation context for warning deduplication

Returns

• ParsedFrontmatter<T> - The parsed result with data and content

pub fn parse<T>(&self, content: &str) -> Result<ParsedFrontmatter<T>>

where T: DeserializeOwned,

Simple parse without templating, just extract frontmatter and content.

Arguments

• content - The content to parse

Returns

• ParsedFrontmatter<T> - The parsed result with data and content

pub fn has_frontmatter(&self, content: &str) -> bool

Check if content has frontmatter.

Arguments

• content - The content to check

Returns

• bool - True if frontmatter is present

pub fn strip_frontmatter(&self, content: &str) -> String

Extract just the content without frontmatter.

Arguments

• content - The content to process

Returns

• String - Content with frontmatter removed

pub fn extract_raw_frontmatter(&self, content: &str) -> Option<String>

Extract just the raw frontmatter string.

Arguments

• content - The content to process

Returns

• Option<String> - Raw frontmatter as YAML string, if present

pub fn get_frontmatter_boundaries( &self, content: &str, ) -> Option<FrontmatterBoundaries>

Get the byte boundaries of the frontmatter section.

This method finds the start and end byte positions of the frontmatter section (including delimiters) in the content. This enables direct frontmatter replacement without string splitting and reassembly.

Arguments

• content - The content to analyze

Returns

• Option<FrontmatterBoundaries> - Boundary positions if frontmatter exists

Example

use agpm_cli::markdown::frontmatter::FrontmatterParser;

let parser = FrontmatterParser::new();
let content = "---\nkey: value\n---\n\nBody content";
let boundaries = parser.get_frontmatter_boundaries(content);
assert!(boundaries.is_some());

pub fn replace_frontmatter( &self, original_content: &str, rendered_frontmatter: &str, boundaries: FrontmatterBoundaries, ) -> String

Replace frontmatter section directly using byte boundaries.

This method replaces the frontmatter section in the original content with rendered frontmatter, preserving the body content exactly as-is. This avoids the error-prone split-and-reassemble pattern.

Arguments

• original_content - The original content with frontmatter
• rendered_frontmatter - The rendered frontmatter YAML string (without delimiters)
• boundaries - The byte boundaries of the frontmatter section

Returns

• String - Content with frontmatter replaced, body unchanged

Example

use agpm_cli::markdown::frontmatter::FrontmatterParser;

let parser = FrontmatterParser::new();
let content = "---\nkey: {{ var }}\n---\n\nBody";
let boundaries = parser.get_frontmatter_boundaries(content).unwrap();
let rendered = "key: value";
let result = parser.replace_frontmatter(content, rendered, boundaries);
assert_eq!(result, "---\nkey: value\n---\n\nBody");

pub fn parse_rendered_content<T>( &self, rendered_content: &str, file_path: &Path, ) -> Result<ParsedFrontmatter<T>>

where T: DeserializeOwned,

Parse frontmatter from already-rendered full file content (Pass 2).

This method extracts and parses frontmatter from content that has already been through full-file template rendering, preserving accurate line numbers. This is used for Pass 2 of the two-pass rendering system.

Arguments

• rendered_content - The fully rendered file content
• file_path - Path to file for error reporting

Returns

• Result<ParsedFrontmatter<T>> - Parsed result with accurate line numbers

pub fn apply_templating( &mut self, content: &str, variant_inputs: Option<&Value>, file_path: &Path, ) -> Result<String>

Apply Tera templating to content.

Always renders the content as a template to catch syntax errors. If variant_inputs is provided, it’s used for template variables. Otherwise, renders with an empty context.

Arguments

• content - The content to template
• variant_inputs - Optional template variables (project, config, etc.)
• file_path - Path to file for error reporting

Returns

• Result<String> - Templated content or error

Trait Implementations

impl Clone for FrontmatterParser

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 FrontmatterParser

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

Formats the value using the given formatter.

impl Default for FrontmatterParser

fn default() -> Self

Returns the “default value” for a type.