adding "include function" feature to ejs.

lib/ejs.js

@@ -528,6 +528,8 @@ function Template(text, opts) {
   }
 
   this.opts = options;
+  this.rootTemplate = opts.rootTemplate || this;
+  this.global = {};
 
   this.regex = this.createRegex();
 }
@@ -555,6 +557,7 @@ Template.prototype = {
   compile: function () {
     var src;
     var fn;
+    var self = this;
     var opts = this.opts;
     var prepended = '';
     var appended = '';
@@ -563,14 +566,21 @@ Template.prototype = {
 
     if (!this.source) {
       this.generateSource();
-      prepended += '  var __output = [], __append = __output.push.bind(__output);' + '\n';
+      prepended += '  var __output = [], __append = function() { var target = __global.__outputStack[0]; return target.push.apply(target, arguments); }' + '\n';
+      if (opts.client) {
+        // TODO: support options.client + include function
+        prepended += '  __global = __global || {}' + '\n';
+      }
+      prepended += '  __global.__outputStack = __global.__outputStack || [];' + '\n';
+      prepended += '  __global.__outputStack.splice(0, 0, __output);' + '\n';
       if (opts.outputFunctionName) {
         prepended += '  var ' + opts.outputFunctionName + ' = __append;' + '\n';
       }
       if (opts._with !== false) {
         prepended +=  '  with (' + opts.localsName + ' || {}) {' + '\n';
         appended += '  }' + '\n';
       }
+      appended += '  __global.__outputStack.splice(0, 1);' + '\n';
       appended += '  return __output.join("");' + '\n';
       this.source = prepended + this.source + appended;
     }
@@ -623,7 +633,7 @@ Template.prototype = {
       else {
         ctor = Function;
       }
-      fn = new ctor(opts.localsName + ', escapeFn, include, rethrow', src);
+      fn = new ctor(opts.localsName + ', escapeFn, include, rethrow, __global', src);
     }
     catch(e) {
       // istanbul ignore else
@@ -643,6 +653,7 @@ Template.prototype = {
     }
 
     if (opts.client) {
+      fn.template = this;
       fn.dependencies = this.dependencies;
       return fn;
     }
@@ -651,15 +662,28 @@ Template.prototype = {
     // created by the source-code, with the passed data as locals
     // Adds a local `include` function which allows full recursive include
     var returnedFn = function (data) {
-      var include = function (path, includeData) {
+      var include = function (includePathOrFunction, includeData) {
         var d = utils.shallowCopy({}, data);
         if (includeData) {
           d = utils.shallowCopy(d, includeData);
         }
-        return includeFile(path, opts)(d);
+
+        if (typeof includePathOrFunction === 'function') {
+          var src = '  var __includeOutput = [];' + '\n'
+            + (opts.client ? '  __global = __global || {};' + '\n' : '')
+            + '  __global.__outputStack.splice(0, 0, __includeOutput);' + '\n'
+            + '  ' + (opts.async ? 'await ' : '') + '__includeFunction(data);' + '\n'
+            + '  __global.__outputStack.splice(0, 1);' + '\n'
+            + '  return __includeOutput.join("");';
+          return new ctor('__includeFunction, data, __global', src)(includePathOrFunction, d, self.rootTemplate.global);
+        } else {
+          opts.rootTemplate = self.rootTemplate;
+          return includeFile(includePathOrFunction, opts)(d);
+        }
       };
-      return fn.apply(opts.context, [data || {}, escapeFn, include, rethrow]);
+      return fn.apply(opts.context, [data || {}, escapeFn, include, rethrow, self.rootTemplate.global]);
     };
+    returnedFn.template = this;
     returnedFn.dependencies = this.dependencies;
     return returnedFn;
   },

test/ejs.js

@@ -1167,6 +1167,10 @@ suite('preprocessor include', function () {
     throw new Error('expected inclusion error');
   });
 
+  test('supports including an function instead of a file path (blocks feature)', function () {
+    assert.equal(ejs.render(fixture('blocks_implementation.ejs'), {}, {filename: path.join(__dirname, 'blocks_implementation.ejs')}),
+      fixture('blocks_result.html'));
+  });
 });
 
 suite('comments', function () {

test/fixtures/blocks_implementation.ejs

@@ -0,0 +1,7 @@
+<% let content = () => { %>
+  <ul>
+    <li>foo</li>
+    <li>bar</li>
+  </ul>
+<% } %>
+<%- include('./fixtures/blocks_layout2', { content, title: 'Blocks For EJS', data: 233 }) %>

test/fixtures/blocks_layout1.ejs

@@ -0,0 +1,8 @@
+<html>
+    <head>
+        <title><%= title%></title>
+    </head>
+<body>
+    <%- include(content)%>
+</body>
+</html>

test/fixtures/blocks_layout2.ejs

@@ -0,0 +1,7 @@
+<% let layout2Content = () => { -%>
+    <h2><%= title%></h2>
+    <main>
+        <%- include(content)%>
+    </main>
+<% } -%>
+<%- include('blocks_layout1', { content: layout2Content, title }) %>

test/fixtures/blocks_result.html

@@ -0,0 +1,18 @@
+
+<html>
+    <head>
+        <title>Blocks For EJS</title>
+    </head>
+<body>
+        <h2>Blocks For EJS</h2>
+    <main>
+
+  <ul>
+    <li>foo</li>
+    <li>bar</li>
+  </ul>
+
+    </main>
+
+</body>
+</html>