Struct CmdPreprocessor

pub struct CmdPreprocessor { /* private fields */ }

A custom preprocessor which will shell out to a 3rd-party program.

Preprocessing Protocol

When the supports_renderer() method is executed, CmdPreprocessor will execute the shell command $cmd supports $renderer. If the renderer is supported, custom preprocessors should exit with a exit code of 0, any other exit code be considered as unsupported.

The run() method is implemented by passing a (PreprocessorContext, Book) tuple to the spawned command ($cmd) as JSON via stdin. Preprocessors should then “return” a processed book by printing it to stdout as JSON. For convenience, the CmdPreprocessor::parse_input() function can be used to parse the input provided by mdbook.

Exiting with a non-zero exit code while preprocessing is considered an error. stderr is passed directly through to the user, so it can be used for logging or emitting warnings if desired.

Examples

An example preprocessor is available in this project’s examples/ directory.

Implementations

impl CmdPreprocessor

pub fn new(name: String, cmd: String) -> CmdPreprocessor

Create a new CmdPreprocessor.

pub fn parse_input<R: Read>(reader: R) -> Result<(PreprocessorContext, Book)>

A convenience function custom preprocessors can use to parse the input written to stdin by a CmdRenderer.

pub fn cmd(&self) -> &str

The command this Preprocessor will invoke.

Trait Implementations

impl Clone for CmdPreprocessor

fn clone(&self) -> CmdPreprocessor

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for CmdPreprocessor

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

Formats the value using the given formatter.

impl PartialEq for CmdPreprocessor

fn eq(&self, other: &CmdPreprocessor) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Preprocessor for CmdPreprocessor

fn name(&self) -> &str

Get the Preprocessor’s name.

fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book>

Run this Preprocessor, allowing it to update the book before it is given to a renderer.

fn supports_renderer(&self, renderer: &str) -> bool

A hint to MDBook whether this preprocessor is compatible with a particular renderer.

impl StructuralPartialEq for CmdPreprocessor