Add feature to parse email subject (#38)

CHANGELOG.md

@@ -1,3 +1,6 @@
+### 3.1.0
+* Add support for email subject.
+
 ### 3.0.0
 
  * Upgrade to Juice 2.  This changes various defaults for inlining styles.

README.md

@@ -47,13 +47,13 @@ var context = {
   meatballCount: 9001
 };
 
-templates.render('meatball-sandwich.html', context, function(err, html, text) {
+templates.render('meatball-sandwich.html', context, function(err, html, text, subject) {
 
   // Send email
   transporter.sendMail({
       from: 'sender@address',
       to: 'receiver@address',
-      subject: 'Meatball delivery',
+      subject: subject,
       html: html,
       text: text
   });
@@ -81,15 +81,15 @@ Path to template files.  Defaults to ```path.join(__dirname, 'templates')```
 
 #### swig (object)
 
-Swig options.  Gets passed to swig.setDefaults().  [See swig documention for more information](http://paularmstrong.github.io/swig/docs/api/#SwigOpts).
+Swig options.  Gets passed to swig.setDefaults().  [See swig documentation for more information](http://paularmstrong.github.io/swig/docs/api/#SwigOpts).
 
 #### filters (object)
 
 An object of Swig filters to set.  Format: { name1: method1, name2: method2 }.  For more information [see Swig documentation for setFilter()](http://paularmstrong.github.io/swig/docs/api/#setFilter).
 
 #### juice (object)
 
-Juice options. [See juice documentation for more inforation](https://github.com/Automattic/juice#options).
+Juice options. [See juice documentation for more information](https://github.com/Automattic/juice#options).
 
 #### rewrite (function(cheerio instance))
 
@@ -135,16 +135,17 @@ new EmailTemplates({
 
 ### render(templateName, context, callback)
 
-Render a template with templateName, with the context provided.  Callback takes three parameters: (error, html, text).
+Render a template with templateName, with the context provided.  Callback takes three parameters: (error, html, text, subject).
 
 Example:
 
 ```js
 var EmailTemplates = require('swig-email-templates');
 var templates = new EmailTemplates();
-templates.render('template.html', { user: 55 }, function (err, html, text) {
+templates.render('template.html', { user: 55 }, function (err, html, text, subject) {
   // html is inlined html
   // text is text equivalent
+  // subject is parsed subject template or null if not found
 })
 ```
 
@@ -156,7 +157,11 @@ You can provide your own text template to override this behaviour.  This should
 
 If the 'text' option is false, then no text alternative will be generated and the callback passed to the EmailTemplate.render() function will receive a falsy value instead of text as its third argument.
 
+#### Behaviour of subject templates
 
+swig-email-templates will attempt to create a text equivalent as well as your HTML. This template should have the same basename as your HTML template but end in `.subject.txt`. This will receive the same context as the HTML template.
+
+Using subject templates, you can generate subject that contains variables.
 
 ## Command Line
 

index.js

@@ -52,6 +52,23 @@ var EmailTemplates = function(options) {
     });
   }
 
+  /*
+   * (Internal) Generate text counterpart to HTML template
+   */
+  this.generateSubject = function(templatePath, context, cb) {
+
+    var textFilename = path.basename(templatePath, path.extname(templatePath)) + '.subject.txt';
+    var textPath = path.resolve(path.dirname(templatePath), textFilename);
+
+    fs.exists(textPath, function(exists) {
+      if (exists) {
+        cb(null, self.useTemplate(textPath, context));
+      } else {
+        cb(null, null);
+      }
+    });
+  }
+
   /*
    * (Internal) Rewrite URLs in a Cheerio doc using a given function
    */
@@ -90,7 +107,11 @@ var EmailTemplates = function(options) {
       self.generateText(templatePath, context, html, function(err, text) {
         if (err) return cb(err);
 
-        cb(null, inlinedHTML, text);
+        self.generateSubject(templatePath, context, function(err, subject) {
+          if (err) return cb(err);
+
+          cb(null, inlinedHTML, text, subject);
+        });
       });
     });
   }

test/api.js

@@ -64,7 +64,7 @@ describe('EmailTemplates', function() {
       });
 
       templates.render('no_text_file_alternative.html', null, function(err, html, text) {
-        assert.equal(text, 'This is a message with bold , just a tester.');
+        assert.equal(text, 'This is a message with bold, just a tester.');
         done(err);
       });
     })

test/output.js

@@ -54,6 +54,7 @@ describe('EmailTemplates output', function() {
 
       var expectedHtml, actualHtml;
       var expectedText, actualText;
+      var expectedSubject, actualSubject;
 
       var pend = new Pend();
 
@@ -65,9 +66,10 @@ describe('EmailTemplates output', function() {
           if (err) return cb(err);
           if (data) context = JSON.parse(data);
 
-          templates.render(testName + '.html', context, function(err, html, text) {
+          templates.render(testName + '.html', context, function(err, html, text, subject) {
             actualHtml = html;
             actualText = text;
+            actualSubject = subject;
             cb(err);
           });
         });
@@ -89,6 +91,14 @@ describe('EmailTemplates output', function() {
         });
       });
 
+      // Try loading the expected text (may not exist)
+      pend.go(function(cb) {
+        attemptReadFile(testPath + '.out.subject.txt', 'utf8', function(err, subject) {
+          expectedSubject = subject;
+          cb(err);
+        });
+      });
+
       // And when they're all done...
       pend.wait(function(err) {
         if (err) return done(err);
@@ -97,6 +107,8 @@ describe('EmailTemplates output', function() {
           assert.strictEqual(actualHtml.trim(), expectedHtml.trim());
         if (expectedText)
           assert.strictEqual(actualText.trim(), expectedText.trim());
+        if (expectedSubject)
+          assert.strictEqual(actualText.trim(), expectedText.trim());
 
         done();
       });

test/templates/simple_vars.json

@@ -1,3 +1,4 @@
 {
-	"hello": "hello"
+	"hello": "hello",
+  "name": "John Doe"
 }

test/templates/simple_vars.out.subject.txt

@@ -0,0 +1 @@
+hello John Doe

test/templates/simple_vars.out.txt

@@ -1 +1 @@
-hello
+hello

test/templates/simple_vars.subject.txt

@@ -0,0 +1 @@
+hello {{ name }}