5 files changed, 103 insertions, 2 deletions
diff --git a/lib/book.js b/lib/book.js
index f615833..a2a11a7 100644
--- a/lib/book.js
+++ b/lib/book.js
@@ -287,6 +287,14 @@ Book.prototype.isMultilingual = function() {
     return this.langs.count() > 0;
 };
 
+// Return true if file is in the scope of this book
+Book.prototype.isInBook = function(filename) {
+    return pathUtil.isInRoot(
+        this.root,
+        this.resolve(filename)
+    );
+};
+
 // Return true if file is in the scope of a child book
 Book.prototype.isInLanguageBook = function(filename) {
     return _.some(this.langs.list(), function(lang) {
diff --git a/lib/fs/index.js b/lib/fs/index.js
index bcd9345..4fd63e9 100644
--- a/lib/fs/index.js
+++ b/lib/fs/index.js
@@ -2,6 +2,7 @@ var _ = require('lodash');
 var path = require('path');
 var Buffer = require('buffer').Buffer;
 var destroy = require('destroy');
+var os = require('os');
 
 var Promise = require('../utils/promise');
 
@@ -45,10 +46,14 @@ FS.prototype.readdir = function(folder) {
     // To implement for each fs
 };
 
-
 // These methods don't require to be redefined, by default it uses .exists, .read, .write, .list
 // For optmization, it can be redefined:
 
+// Allocate a new temporary directory
+FS.prototype.tmpdir = function() {
+    return path.resolve(os.tmpdir(), _.uniqueId('gitbook_tmp_'));
+};
+
 // List files in a directory
 FS.prototype.listFiles = function(folder) {
     return this.readdir(folder)
diff --git a/lib/template/index.js b/lib/template/index.js
index 833ff76..a3021e6 100644
--- a/lib/template/index.js
+++ b/lib/template/index.js
@@ -7,6 +7,7 @@ var Promise = require('../utils/promise');
 var error = require('../utils/error');
 var gitbook = require('../gitbook');
 var defaultBlocks = require('./blocks');
+var Loader = require('./loader');
 
 // Return extension name for a specific block
 function blockExtName(name) {
@@ -23,6 +24,10 @@ function TemplateEngine(book) {
     this.book = book;
     this.log = book.log;
 
+    // Create file loader
+    this.loader = new Loader(this);
+
+    // Create nunjucks instance
     this.env = new nunjucks.Environment(
         this.loader,
         {
@@ -57,6 +62,14 @@ function TemplateEngine(book) {
     this.addBlocks(defaultBlocks);
 }
 
+// Interpolate a string content to replace shortcuts according to the filetype
+TemplateEngine.prototype.interpolate = function(filepath, source) {
+    var parser = parsers.get(path.extname(filepath));
+    var type = parser? parser.name : null;
+
+    return this.applyShortcuts(type, source);
+};
+
 // Add a new custom filter
 TemplateEngine.prototype.addFilter = function(filterName, func) {
     try {
diff --git a/lib/template/loader.js b/lib/template/loader.js
index e69de29..23ffb77 100644
--- a/lib/template/loader.js
+++ b/lib/template/loader.js
@@ -0,0 +1,75 @@
+var path = require('path');
+var nunjucks = require('nunjucks');
+
+var Git = require('../utils/git');
+var pathUtil = require('../utils/path');
+
+// The loader should handle relative and git url
+var Loader = nunjucks.Loader.extend({
+    async: true,
+
+    init: function(engine, opts) {
+        this.engine = engine;
+        this.book = engine.book;
+        this.fs = engine.book.fs;
+
+        this.git = new Git(this.fs.tmpdir());
+    },
+
+    getSource: function(soureURL, callback) {
+        var that = this;
+
+        this.git.resolveFile(soureURL)
+        .then(function(filepath) {
+            // Is local file
+            if (!filepath) {
+                filepath = that.book.resolve(soureURL);
+            } else {
+                that.book.log.debug.ln('resolve from git', soureURL, 'to', filepath);
+            }
+
+            //  Read file from absolute path
+            return that.fs.readAsString(filepath)
+            .then(function(source) {
+                return that.engine.interpolate(filepath, source);
+            })
+            .then(function(source) {
+                return {
+                    src: source,
+                    path: filepath,
+
+                    // We disable cache since content is modified (shortcuts, ...)
+                    noCache: true
+                };
+            });
+        })
+        .nodeify(callback);
+    },
+
+    resolve: function(from, to) {
+        // If origin is in the book, we enforce result file to be in the book
+        if (this.book.isInBook(from)) {
+            return this.book.resolve(
+                this.book.relative(path.dirname(from)),
+                to
+            );
+        }
+
+        // If origin is in a git repository, we resolve file in the git repository
+        var gitRoot = this.git.resolveRoot(from);
+        if (gitRoot) {
+            return pathUtil.resolveInRoot(gitRoot, to);
+        }
+
+        // If origin is not in the book (include from a git content ref)
+        return path.resolve(path.dirname(from), to);
+    },
+
+    // Handle all files as relative, so that nunjucks pass responsability to 'resolve'
+    // Only git urls are considered as absolute
+    isRelative: function(filename) {
+        return !Git.isUrl(filename);
+    }
+});
+
+module.exports = Loader;
diff --git a/test/all.js b/test/all.js
index 0f55603..827a182 100644
--- a/test/all.js
+++ b/test/all.js
@@ -7,8 +7,8 @@ require('./glossary');
 require('./langs');
 require('./parse');
 
-require('./template');
 require('./git');
+require('./template');
 
 // Output
 require('./output-json');