Initial Preprocessor trait implementation

src/book/mod.rs

@@ -23,7 +23,7 @@ use toml::Value;
 
 use utils;
 use renderer::{CmdRenderer, HtmlHandlebars, RenderContext, Renderer};
-use preprocess;
+use preprocess::{self, Preprocessor};
 use errors::*;
 
 use config::Config;
@@ -40,6 +40,9 @@ pub struct MDBook {
 
     /// The URL used for live reloading when serving up the book.
     pub livereload: Option<String>,
+
+    /// List of pre-processors to be run on the book
+    preprocessors: Vec<Box<Preprocessor>>
 }
 
 impl MDBook {
@@ -86,12 +89,15 @@ impl MDBook {
 
         let renderers = determine_renderers(&config);
 
+        let preprocessors = vec![];
+
         Ok(MDBook {
             root,
             config,
             book,
             renderers,
             livereload,
+            preprocessors,
         })
     }
 
@@ -192,6 +198,13 @@ impl MDBook {
         self
     }
 
+    /// You can add a new preprocessor by using this method.
+    /// The only requirement is for your renderer to implement the Preprocessor trait.
+    pub fn with_preprecessor<P: Preprocessor + 'static>(&mut self, preprocessor: P) -> &mut Self {
+        self.preprocessors.push(Box::new(preprocessor));
+        self
+    }
+
     /// Run `rustdoc` tests on the book, linking against the provided libraries.
     pub fn test(&mut self, library_paths: Vec<&str>) -> Result<()> {
         let library_args: Vec<&str> = (0..library_paths.len())

src/preprocess/mod.rs

@@ -1 +1,5 @@
 pub mod links;
+
+pub trait Preprocessor {
+
+}