diff options
Diffstat (limited to 'vendor/mdbook/examples')
-rw-r--r-- | vendor/mdbook/examples/nop-preprocessor.rs | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/vendor/mdbook/examples/nop-preprocessor.rs b/vendor/mdbook/examples/nop-preprocessor.rs new file mode 100644 index 000000000..ace400936 --- /dev/null +++ b/vendor/mdbook/examples/nop-preprocessor.rs @@ -0,0 +1,104 @@ +use crate::nop_lib::Nop; +use clap::{App, Arg, ArgMatches}; +use mdbook::book::Book; +use mdbook::errors::Error; +use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext}; +use semver::{Version, VersionReq}; +use std::io; +use std::process; + +pub fn make_app() -> App<'static> { + App::new("nop-preprocessor") + .about("A mdbook preprocessor which does precisely nothing") + .subcommand( + App::new("supports") + .arg(Arg::new("renderer").required(true)) + .about("Check whether a renderer is supported by this preprocessor"), + ) +} + +fn main() { + let matches = make_app().get_matches(); + + // Users will want to construct their own preprocessor here + let preprocessor = Nop::new(); + + if let Some(sub_args) = matches.subcommand_matches("supports") { + handle_supports(&preprocessor, sub_args); + } else if let Err(e) = handle_preprocessing(&preprocessor) { + eprintln!("{}", e); + process::exit(1); + } +} + +fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> { + let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?; + + let book_version = Version::parse(&ctx.mdbook_version)?; + let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?; + + if !version_req.matches(&book_version) { + eprintln!( + "Warning: The {} plugin was built against version {} of mdbook, \ + but we're being called from version {}", + pre.name(), + mdbook::MDBOOK_VERSION, + ctx.mdbook_version + ); + } + + let processed_book = pre.run(&ctx, book)?; + serde_json::to_writer(io::stdout(), &processed_book)?; + + Ok(()) +} + +fn handle_supports(pre: &dyn Preprocessor, sub_args: &ArgMatches) -> ! { + let renderer = sub_args.value_of("renderer").expect("Required argument"); + let supported = pre.supports_renderer(renderer); + + // Signal whether the renderer is supported by exiting with 1 or 0. + if supported { + process::exit(0); + } else { + process::exit(1); + } +} + +/// The actual implementation of the `Nop` preprocessor. This would usually go +/// in your main `lib.rs` file. +mod nop_lib { + use super::*; + + /// A no-op preprocessor. + pub struct Nop; + + impl Nop { + pub fn new() -> Nop { + Nop + } + } + + impl Preprocessor for Nop { + fn name(&self) -> &str { + "nop-preprocessor" + } + + fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book, Error> { + // In testing we want to tell the preprocessor to blow up by setting a + // particular config value + if let Some(nop_cfg) = ctx.config.get_preprocessor(self.name()) { + if nop_cfg.contains_key("blow-up") { + anyhow::bail!("Boom!!1!"); + } + } + + // we *are* a no-op preprocessor after all + Ok(book) + } + + fn supports_renderer(&self, renderer: &str) -> bool { + renderer != "not-supported" + } + } +} |