Closes hapijs#846

docs/Reference.md

@@ -243,6 +243,10 @@ When creating a server instance, the following options configure the server's be
       directory.
     - `partialsPath` - the root file path where partials are located. Partials are small segments of template code that can be nested and reused
       throughout other templates. Defaults to no partials support (empty path).
+    - `helpersPath` - the directory path where helpers are located. Helpers are functions used within templates to perform transformations
+      and other data manipulations using the template context or other inputs. Each '.js' file in the helpers directory is loaded and the file name
+      is used as the helper name. The files must export a single method with the signature `function(context)` and return a string. Sub-folders are
+      not supported and are ignored. Defaults to no helpers support (empty path).
     - `basePath` - a base path used as prefix for `path` and `partialsPath`. No default.
     - `layout` - if set to `true`, layout support is enabled. A layout is a single template file used as the parent template for other view templates
       in the same engine. The layout template name must be 'layout.ext' where 'ext' is the engine's extension.

lib/schema.js

@@ -90,6 +90,7 @@ internals.serverSchema = {
         allowAbsolutePaths: T.Boolean(),
         allowInsecureAccess: T.Boolean(),
         partialsPath: T.String(),
+        helpersPath: T.String(),
         contentType: T.String()
     }).nullOk(),
     maxSockets: T.Number().nullOk()
@@ -196,6 +197,7 @@ internals.viewSchema = {
     allowAbsolutePaths: T.Boolean(),
     allowInsecureAccess: T.Boolean(),
     partialsPath: T.String().emptyOk(),
+    helpersPath: T.String().emptyOk(),
     contentType: T.String(),
     compileMode: T.String().valid('sync', 'async')
 };

lib/views.js

@@ -71,9 +71,10 @@ exports = module.exports = internals.Manager = function (options) {
             engine.cache = {};
         }
 
-        // Load partials
+        // Load partials and helpers
 
         self._loadPartials(engine);
+        self._loadHelpers(engine);
 
         // Set engine
 
@@ -135,6 +136,35 @@ internals.Manager.prototype._loadPartials = function (engine) {
 };
 
 
+internals.Manager.prototype._loadHelpers = function (engine) {
+
+    var self = this;
+
+    if (!engine.config.helpersPath ||
+        !engine.module.hasOwnProperty('registerHelper')) {
+
+        return;
+    }
+
+    var files = [];
+
+    var path = Path.join(engine.config.basePath || '', engine.config.helpersPath);
+    Fs.readdirSync(path).forEach(function (file) {
+
+        file = Path.join(path, file);
+        var stat = Fs.statSync(file);
+        if (stat.isFile() &&
+            Path.basename(file)[0] !== '.' &&
+            Path.extname(file) === '.js') {
+
+            var offset = path.slice(-1) === '/' ? 0 : 1;
+            var name = file.slice(path.length + offset, -3);
+            engine.module.registerHelper(name, require(file));
+        }
+    });
+};
+
+
 internals.Manager.prototype.render = function (filename, context, options, callback) {
 
     var self = this;

test/unit/templates/valid/helpers/uppercase.js

@@ -0,0 +1,4 @@
+module.exports = function (context) {
+
+    return context.toUpperCase();
+};

test/unit/templates/valid/testHelpers.html

@@ -0,0 +1 @@
+<p>This is all {{uppercase this.something}} and this is how we like it!</p>

test/unit/views.js

@@ -188,11 +188,12 @@ describe('Views', function () {
             });
         });
 
-        it('should skip loading partial if engine does not have registerPartial method', function (done) {
+        it('should skip loading partials and helpers if engine does not support them', function (done) {
 
             var tempView = new Views({
                 path: viewsPath + '/valid',
                 partialsPath: viewsPath + '/valid/partials',
+                helpersPath: viewsPath + '/valid/helpers',
                 engines: { 'html': 'jade' }
             });
 
@@ -203,6 +204,21 @@ describe('Views', function () {
                 done();
             });
         });
+
+        it('should load helpers and render them', function (done) {
+
+            var tempView = new Views({
+                engines: { 'html': 'handlebars' },
+                path: viewsPath + '/valid',
+                helpersPath: viewsPath + '/valid/helpers'
+            });
+
+            tempView.render('testHelpers', { something: 'uppercase' }, function (err, rendered, config) {
+
+                expect(rendered).to.equal('<p>This is all UPPERCASE and this is how we like it!</p>');
+                done();
+            });
+        });
     });
 
     describe('#handler', function () {