Factor out replace_all preprocessor

src/book/mod.rs

@@ -89,7 +89,7 @@ impl MDBook {
 
         let renderers = determine_renderers(&config);
 
-        let preprocessors = vec![];
+        let preprocessors = determine_preprocessors(&config);
 
         Ok(MDBook {
             root,
@@ -215,16 +215,18 @@ impl MDBook {
 
         let temp_dir = TempDir::new("mdbook")?;
 
+        let replace_all_preprocessor = preprocess::links::ReplaceAllPreprocessor {
+            src_dir: self.source_dir(),
+        };
+
+        replace_all_preprocessor.run(&mut self.book)?;
+
         for item in self.iter() {
             if let BookItem::Chapter(ref ch) = *item {
                 if !ch.path.as_os_str().is_empty() {
                     let path = self.source_dir().join(&ch.path);
-                    let base = path.parent()
-                        .ok_or_else(|| String::from("Invalid bookitem path!"))?;
-                    let content = utils::fs::file_to_string(&path)?;
-                    // Parse and expand links
-                    let content = preprocess::links::replace_all(&content, base)?;
                     println!("[*]: Testing file: {:?}", path);
+                    let content = utils::fs::file_to_string(&path)?;
 
                     // write preprocessed file to tempdir
                     let path = temp_dir.path().join(&ch.path);
@@ -322,6 +324,13 @@ fn determine_renderers(config: &Config) -> Vec<Box<Renderer>> {
     renderers
 }
 
+/// Look at the `Config` and try to figure out what preprocessors to run.
+fn determine_preprocessors(config: &Config) -> Vec<Box<Preprocessor>> {
+    let mut preprocessors: Vec<Box<Preprocessor>> = Vec::new();
+
+    preprocessors
+}
+
 fn interpret_custom_renderer(key: &str, table: &Value) -> Box<Renderer> {
     // look for the `command` field, falling back to using the key
     // prepended by "mdbook-"

src/preprocess/links.rs

@@ -5,9 +5,35 @@ use utils::fs::file_to_string;
 use utils::take_lines;
 use errors::*;
 
+use super::Preprocessor;
+use book::{Book, BookItem};
+
 const ESCAPE_CHAR: char = '\\';
 
-pub fn replace_all<P: AsRef<Path>>(s: &str, path: P) -> Result<String> {
+pub struct ReplaceAllPreprocessor {
+    pub src_dir: PathBuf
+}
+
+impl Preprocessor for ReplaceAllPreprocessor {
+    fn run(&self, book: &mut Book) -> Result<()> {
+        for section in &mut book.sections {
+            match *section {
+                BookItem::Chapter(ref mut ch) => {
+                    let content = ::std::mem::replace(&mut ch.content, String::new());
+                    let base = ch.path.parent()
+                        .map(|dir| self.src_dir.join(dir))
+                        .ok_or_else(|| String::from("Invalid bookitem path!"))?;
+                    ch.content = replace_all(&content, base)?
+                }
+                _ => {}
+            }
+        }
+
+        Ok(())
+    }
+}
+
+fn replace_all<P: AsRef<Path>>(s: &str, path: P) -> Result<String> {
     // When replacing one thing in a string by something with a different length,
     // the indices after that will not correspond,
     // we therefore have to store the difference to correct this

src/preprocess/mod.rs

@@ -1,5 +1,9 @@
 pub mod links;
 
-pub trait Preprocessor {
+use book::Book;
+use errors::*;
 
+
+pub trait Preprocessor {
+    fn run(&self, book: &mut Book) -> Result<()>;
 }

src/renderer/html_handlebars/hbs_renderer.rs

@@ -1,5 +1,4 @@
 use renderer::html_handlebars::helpers;
-use preprocess;
 use renderer::{RenderContext, Renderer};
 use book::{Book, BookItem, Chapter};
 use config::{Config, HtmlConfig, Playpen};
@@ -50,12 +49,6 @@ impl HtmlHandlebars {
         match *item {
             BookItem::Chapter(ref ch) => {
                 let content = ch.content.clone();
-                let base = ch.path.parent()
-                    .map(|dir| ctx.src_dir.join(dir))
-                    .expect("All chapters must have a parent directory");
-
-                // Parse and expand links
-                let content = preprocess::links::replace_all(&content, base)?;
                 let content = utils::render_markdown(&content, ctx.html_config.curly_quotes);
                 print_content.push_str(&content);
 
@@ -322,7 +315,6 @@ impl Renderer for HtmlHandlebars {
             let ctx = RenderItemContext {
                 handlebars: &handlebars,
                 destination: destination.to_path_buf(),
-                src_dir: src_dir.clone(),
                 data: data.clone(),
                 is_index: i == 0,
                 html_config: html_config.clone(),
@@ -634,7 +626,6 @@ fn partition_source(s: &str) -> (String, String) {
 struct RenderItemContext<'a> {
     handlebars: &'a Handlebars,
     destination: PathBuf,
-    src_dir: PathBuf,
     data: serde_json::Map<String, serde_json::Value>,
     is_index: bool,
     html_config: HtmlConfig,