4 files changed, 66 insertions, 11 deletions

diff --git a/lib/generate/index.js b/lib/generate/index.js
index 444f75f..53de646 100644
--- a/lib/generate/index.js
+++ b/lib/generate/index.js
@@ -271,13 +271,31 @@ var generateBook = function(options) {
 
         // Get summary
         .then(function() {
-            return fs.readFile(path.join(options.input, "SUMMARY.md"), "utf-8")
-            .then(function(_summary) {
-                options.summary = parse.summary(_summary);
+            var summary = {
+                path: path.join(options.input, "SUMMARY.md")
+            };
 
-                // Parse navigation
-                options.navigation = parse.navigation(options.summary);
-            });
+            var _callHook = function(name) {
+                return generator.callHook(name, summary)
+                .then(function(_summary) {
+                    summary = _summary;
+                    return summary;
+                });
+            };
+
+            return fs.readFile(summary.path, "utf-8")
+                .then(function(_content) {
+                    summary.content = _content;
+                    return _callHook("summary:before");
+                })
+                .then(function() {
+                    summary.content = parse.summary(summary.content);
+                    return _callHook("summary:after");
+                })
+                .then(function() {
+                    options.summary = summary.content;
+                    options.navigation = parse.navigation(options.summary);
+                })
         })
 
         // Skip processing some files
diff --git a/lib/parse/code_include.js b/lib/parse/code_include.js
new file mode 100644
index 0000000..f4656f1
--- /dev/null
+++ b/lib/parse/code_include.js
@@ -0,0 +1,20 @@
+var fs = require('fs');
+var path = require('path');
+
+module.exports = function(code, folder) {
+    folder = folder || '';
+
+    return code.replace(/{{([\s\S]+?)}}/g, function(match, filename) {
+        // Normalize filename
+        var fname = path.join(folder, filename.trim());
+
+        // Try including snippet from FS
+        try {
+            // Trim trailing newlines/space of imported snippets
+            return fs.readFileSync(fname, 'utf8').trimRight();
+        } catch(err) {}
+
+        // If fails leave content as is
+        return match;
+    });
+};
diff --git a/lib/parse/page.js b/lib/parse/page.js
index 6cfd3ca..d714a15 100644
--- a/lib/parse/page.js
+++ b/lib/parse/page.js
@@ -5,6 +5,7 @@ var hljs = require('highlight.js');
 var lex = require('./lex');
 var renderer = require('./renderer');
 
+var codeInclude = require('./code_include');
 var lnormalize = require('../utils/lang').normalize;
 
 
@@ -74,15 +75,20 @@ function parsePage(src, options) {
             // Main language
             var lang = validLangs ? langs[0] : null;
 
+            // codeInclude shortcut
+            var ci = function(code) {
+                return codeInclude(code, options.dir);
+            };
+
             return {
                 id: section.id,
                 type: section.type,
                 content: render(nonCodeNodes),
                 lang: lang,
                 code: {
-                    base: codeNodes[0].text,
-                    solution: codeNodes[1].text,
-                    validation: codeNodes[2].text,
+                    base: ci(codeNodes[0].text),
+                    solution: ci(codeNodes[1].text),
+                    validation: ci(codeNodes[2].text),
                     // Context is optional
                     context: codeNodes[3] ? codeNodes[3].text : null,
                 }
diff --git a/lib/parse/renderer.js b/lib/parse/renderer.js
index 4da312e..dcbc261 100644
--- a/lib/parse/renderer.js
+++ b/lib/parse/renderer.js
@@ -1,6 +1,7 @@
 var url = require('url');
 var inherits = require('util').inherits;
 var links = require('../utils').links;
+var codeInclude = require('./code_include');
 
 
 var path = require('path');
@@ -56,7 +57,7 @@ GitBookRenderer.prototype.link = function(href, title, text) {
 
     // Relative link, rewrite it to point to github repo
     if(links.isRelative(_href)) {
-        if (path.extname(_href) == ".md") {
+        if (path.extname(parsed.path) == ".md") {
             _href = links.toAbsolute(_href, o.dir || "./", o.outdir || "./");
 
             if (o.singleFile) {
@@ -125,7 +126,7 @@ GitBookRenderer.prototype._createCheckboxAndRadios = function(text) {
     var length = splittedText.length;
     var label = '<label class="quiz-label" for="' + quizIdentifier + '">' + splittedText[length - 1] + '</label>';
     return text.replace(fieldRegex, field).replace(splittedText[length - 1], label);
-}
+};
 
 GitBookRenderer.prototype.tablecell = function(content, flags) {
     return GitBookRenderer.super_.prototype.tablecell(this._createCheckboxAndRadios(content), flags);
@@ -135,5 +136,15 @@ GitBookRenderer.prototype.listitem = function(text) {
     return GitBookRenderer.super_.prototype.listitem(this._createCheckboxAndRadios(text));
 };
 
+GitBookRenderer.prototype.code = function(code, lang, escaped) {
+    return GitBookRenderer.super_.prototype.code.call(
+        this,
+        // Import code snippets
+        codeInclude(code, this._extra_options.dir),
+        lang,
+        escaped
+    );
+};
+
 // Exports
 module.exports = GitBookRenderer;