read config from file

src/bin/main.rs

@@ -1,6 +1,7 @@
 extern crate crowbook;
 
-use crowbook::{HtmlRenderer, Parser, French, Book};
+use crowbook::{HtmlRenderer, Book};
+use std::env;
 
 
 
@@ -18,8 +19,15 @@ cover: book-example/cover.png
 + book_example/chapitre_03.md
 ";
 
-    let mut book = Book::new();
-    book.set_from_config(config).unwrap();
-    let mut html = HtmlRenderer::new(&book);
-    println!("{}", html.render_book().unwrap());
+    let mut args = env::args();
+    args.next(); //discard program name
+
+    match args.next() {
+        None => println!("Needs the name of a book config file"),
+        Some(ref s) => {
+            let mut book = Book::new_from_file(s).unwrap();
+            let mut html = HtmlRenderer::new(&book);
+            println!("{}", html.render_book().unwrap());
+        }
+    }
 }

src/lib/book.rs

@@ -1,6 +1,9 @@
 use error::{Error,Result};
 use cleaner::{Cleaner, French};
 
+use std::fs::File;
+use std::io::Read;
+
 use mustache::MapBuilder;
 
 // Numbering for a given chapter
@@ -40,6 +43,18 @@ impl Book {
         }
     }
 
+    /// Creates a new book from a file
+    pub fn new_from_file(filename: &str) -> Result<Book> {
+        let mut f = try!(File::open(filename).map_err(|_| Error::FileNotFound(String::from(filename))));
+        let mut s = String::new();
+
+        try!(f.read_to_string(&mut s).map_err(|_| Error::ConfigParser("file contains invalid UTF-8, could not parse it",
+                                                                      String::from(filename))));
+        let mut book = Book::new();
+        try!(book.set_from_config(&s));
+        Ok(book)
+    }
+
     /// Returns a MapBuilder, to be used (and completed) for templating
     pub fn get_mapbuilder(&self) -> MapBuilder {
         MapBuilder::new()