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dc9dc135 | 1 | use crate::nop_lib::Nop; |
9fa01778 XL |
2 | use clap::{App, Arg, ArgMatches, SubCommand}; |
3 | use mdbook::book::Book; | |
4 | use mdbook::errors::Error; | |
5 | use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext}; | |
94222f64 | 6 | use semver::{Version, VersionReq}; |
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7 | use std::io; |
8 | use std::process; | |
9 | ||
10 | pub fn make_app() -> App<'static, 'static> { | |
11 | App::new("nop-preprocessor") | |
12 | .about("A mdbook preprocessor which does precisely nothing") | |
13 | .subcommand( | |
14 | SubCommand::with_name("supports") | |
15 | .arg(Arg::with_name("renderer").required(true)) | |
16 | .about("Check whether a renderer is supported by this preprocessor"), | |
17 | ) | |
18 | } | |
19 | ||
20 | fn main() { | |
21 | let matches = make_app().get_matches(); | |
22 | ||
23 | // Users will want to construct their own preprocessor here | |
24 | let preprocessor = Nop::new(); | |
25 | ||
26 | if let Some(sub_args) = matches.subcommand_matches("supports") { | |
27 | handle_supports(&preprocessor, sub_args); | |
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28 | } else if let Err(e) = handle_preprocessing(&preprocessor) { |
29 | eprintln!("{}", e); | |
30 | process::exit(1); | |
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31 | } |
32 | } | |
33 | ||
34 | fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> { | |
35 | let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?; | |
36 | ||
94222f64 XL |
37 | let book_version = Version::parse(&ctx.mdbook_version)?; |
38 | let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?; | |
39 | ||
40 | if version_req.matches(&book_version) != true { | |
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41 | eprintln!( |
42 | "Warning: The {} plugin was built against version {} of mdbook, \ | |
43 | but we're being called from version {}", | |
44 | pre.name(), | |
45 | mdbook::MDBOOK_VERSION, | |
46 | ctx.mdbook_version | |
47 | ); | |
48 | } | |
49 | ||
50 | let processed_book = pre.run(&ctx, book)?; | |
51 | serde_json::to_writer(io::stdout(), &processed_book)?; | |
52 | ||
53 | Ok(()) | |
54 | } | |
55 | ||
56 | fn handle_supports(pre: &dyn Preprocessor, sub_args: &ArgMatches) -> ! { | |
57 | let renderer = sub_args.value_of("renderer").expect("Required argument"); | |
58 | let supported = pre.supports_renderer(&renderer); | |
59 | ||
60 | // Signal whether the renderer is supported by exiting with 1 or 0. | |
61 | if supported { | |
62 | process::exit(0); | |
63 | } else { | |
64 | process::exit(1); | |
65 | } | |
66 | } | |
67 | ||
68 | /// The actual implementation of the `Nop` preprocessor. This would usually go | |
69 | /// in your main `lib.rs` file. | |
70 | mod nop_lib { | |
71 | use super::*; | |
72 | ||
73 | /// A no-op preprocessor. | |
74 | pub struct Nop; | |
75 | ||
76 | impl Nop { | |
77 | pub fn new() -> Nop { | |
78 | Nop | |
79 | } | |
80 | } | |
81 | ||
82 | impl Preprocessor for Nop { | |
83 | fn name(&self) -> &str { | |
84 | "nop-preprocessor" | |
85 | } | |
86 | ||
87 | fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book, Error> { | |
88 | // In testing we want to tell the preprocessor to blow up by setting a | |
89 | // particular config value | |
90 | if let Some(nop_cfg) = ctx.config.get_preprocessor(self.name()) { | |
91 | if nop_cfg.contains_key("blow-up") { | |
f035d41b | 92 | anyhow::bail!("Boom!!1!"); |
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93 | } |
94 | } | |
95 | ||
96 | // we *are* a no-op preprocessor after all | |
97 | Ok(book) | |
98 | } | |
99 | ||
100 | fn supports_renderer(&self, renderer: &str) -> bool { | |
101 | renderer != "not-supported" | |
102 | } | |
103 | } | |
104 | } |