Added open graph tags for ghost head helper

issue #3900
- uses isPrivacyDisabled helper to see if useStructuredData has been disabled in config.js
- adds an array of promises to deal with asynchronous data
- resolves asynchronous data then adds open graph tags after canonical link
- featured image and tags are only added if present
- open graph tags only added on post and page
- adds unit test to check correct data is returned
- updates other unit tests to reflect changes

PRIVACY.md

@@ -41,3 +41,10 @@ RPC pings only happen when Ghost is running in the `production` environment.
 ### Sharing Buttons
 
 The default theme which comes with Ghost contains three sharing buttons to [Twitter](http://twitter.com), [Facebook](http://facebook.com), and [Google Plus](http://plus.google.com). No resources are loaded from any services, however the buttons do allow visitors to your blog to share your content publicly on these respective networks.
+
+
+### Structured Data
+
+Ghost outputs Meta data for your blog that allows published content to be more easily machine-readable. This allows content to be easily discoverable in search engines as well as popular social networks where blog posts are typically shared.
+
+This includes output for post.hbs in {{ghost_head}} based on the Open Graph protocol specification.

core/client/controllers/post-settings-menu.js

@@ -131,7 +131,7 @@ var PostSettingsMenuController = Ember.ObjectController.extend({
 
         if (placeholder.length > 156) {
             // Limit to 156 characters
-            placeholder = placeholder.substring(0,156).trim();
+            placeholder = placeholder.substring(0, 156).trim();
             placeholder = Ember.Handlebars.Utils.escapeExpression(placeholder);
             placeholder = new Ember.Handlebars.SafeString(placeholder + '…');
         }

core/server/helpers/index.js

@@ -491,20 +491,33 @@ coreHelpers.ghost_head = function (options) {
     /*jshint unused:false*/
     var self = this,
         blog = config.theme,
+        useStructuredData = !config.isPrivacyDisabled('useStructuredData'),
         head = [],
         majorMinor = /^(\d+\.)?(\d+)/,
         trimmedVersion = this.version,
         trimmedUrlpattern = /.+(?=\/page\/\d*\/)/,
-        trimmedUrl, next, prev;
+        trimmedUrl, next, prev, tags,
+        ops = [],
+        structuredData;
 
     trimmedVersion = trimmedVersion ? trimmedVersion.match(majorMinor)[0] : '?';
 
-    head.push('<meta name="generator" content="Ghost ' + trimmedVersion + '" />');
+    // Push Async calls to an array of promises
+    ops.push(coreHelpers.url.call(self, {hash: {absolute: true}}));
+    ops.push(coreHelpers.meta_description.call(self));
+    ops.push(coreHelpers.meta_title.call(self));
 
-    head.push('<link rel="alternate" type="application/rss+xml" title="' +
+    // Resolves promises then push pushes meta data into ghost_head
-        _.escape(blog.title)  + '" href="' + config.urlFor('rss') + '">');
+    return Promise.settle(ops).then(function (results) {
+        var url = results[0].value(),
+            metaDescription = results[1].value(),
+            metaTitle = results[2].value(),
+            publishedDate, modifiedDate;
+
+        if (!metaDescription) {
+            metaDescription = coreHelpers.excerpt.call(self.post, {hash: {words: '40'}});
+        }
 
-    return coreHelpers.url.call(self, {hash: {absolute: true}}).then(function (url) {
         head.push('<link rel="canonical" href="' + url + '" />');
 
         if (self.pagination) {
@@ -521,9 +534,44 @@ coreHelpers.ghost_head = function (options) {
             }
         }
 
+        // Test to see if we are on a post page and that Structured data has not been disabled in config.js
+        if (self.post && useStructuredData) {
+            publishedDate = moment(self.post.published_at).toISOString();
+            modifiedDate = moment(self.post.updated_at).toISOString();
+
+            structuredData = {
+                'og:site_name': _.escape(blog.title),
+                'og:type': 'article',
+                'og:title': metaTitle,
+                'og:description': metaDescription + '...',
+                'og:url': url,
+                'article:published_time': publishedDate,
+                'article:modified_time': modifiedDate
+            };
+
+            if (self.post.image)  {
+                structuredData['og:image'] = _.escape(blog.url) + self.post.image;
+            }
+
+            _.each(structuredData, function (content, property) {
+                head.push('<meta property="' + property + '" content="' + content + '" />');
+            });
+
+            // Calls tag helper and assigns an array of tag names for a post
+            tags = coreHelpers.tags.call(self.post, {hash: {autolink: 'false'}}).string.split(',');
+
+            _.each(tags, function (tag) {
+                if (tag !== '') {
+                    head.push('<meta property="article:tag" content="' + tag.trim() + '" />');
+                }
+            });
+        }
+        head.push('<meta name="generator" content="Ghost ' + trimmedVersion + '" />');
+        head.push('<link rel="alternate" type="application/rss+xml" title="' +
+            _.escape(blog.title)  + '" href="' + config.urlFor('rss') + '" />');
         return filters.doFilter('ghost_head', head);
     }).then(function (head) {
-        var headString = _.reduce(head, function (memo, item) { return memo + '\n' + item; }, '');
+        var headString = _.reduce(head, function (memo, item) { return memo + '\n    ' + item; }, '');
         return new hbs.handlebars.SafeString(headString.trim());
     });
 };
@@ -539,7 +587,7 @@ coreHelpers.ghost_foot = function (options) {
     }));
 
     return filters.doFilter('ghost_foot', foot).then(function (foot) {
-        var footString = _.reduce(foot, function (memo, item) { return memo + ' ' + item; }, '');
+        var footString = _.reduce(foot, function (memo, item) { return memo + '\n' + item; }, '\n');
         return new hbs.handlebars.SafeString(footString.trim());
     });
 };

core/test/unit/server_helpers_index_spec.js

@@ -567,11 +567,11 @@ describe('Core Helpers', function () {
 
         it('returns meta tag string', function (done) {
             config.set({url: 'http://testurl.com/'});
-            helpers.ghost_head.call({version: '0.3.0'}).then(function (rendered) {
+            helpers.ghost_head.call({version: '0.3.0', post: false}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.3" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/">\n' +
+                    '    <meta name="generator" content="Ghost 0.3" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
 
                 done();
             }).catch(done);
@@ -581,9 +581,41 @@ describe('Core Helpers', function () {
             config.set({url: 'http://testurl.com/'});
             helpers.ghost_head.call({version: '0.9'}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.9" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/">\n' +
+                    '    <meta name="generator" content="Ghost 0.9" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
+
+                done();
+            }).catch(done);
+        });
+
+        it('returns open graph data on post page', function (done) {
+            config.set({url: 'http://testurl.com/'});
+            var post = {
+                meta_description: 'blog description',
+                title: 'Welcome to Ghost',
+                image: '/test-image.png',
+                published_at:  moment('2008-05-31T19:18:15').toISOString(),
+                updated_at: moment('2014-10-06T15:23:54').toISOString(),
+                tags: [{name: 'tag1'}, {name: 'tag2'}, {name: 'tag3'}]
+            };
+
+            helpers.ghost_head.call({relativeUrl: '/post/', version: '0.3.0', post: post}).then(function (rendered) {
+                should.exist(rendered);
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/post/" />\n' +
+                        '    <meta property="og:site_name" content="Ghost" />\n' +
+                        '    <meta property="og:type" content="article" />\n' +
+                        '    <meta property="og:title" content="Welcome to Ghost" />\n' +
+                        '    <meta property="og:description" content="blog description..." />\n' +
+                        '    <meta property="og:url" content="http://testurl.com/post/" />\n' +
+                        '    <meta property="article:published_time" content="' + post.published_at + '" />\n' +
+                        '    <meta property="article:modified_time" content="' + post.updated_at + '" />\n' +
+                        '    <meta property="og:image" content="http://testurl.com/test-image.png" />\n' +
+                        '    <meta property="article:tag" content="tag1" />\n' +
+                        '    <meta property="article:tag" content="tag2" />\n' +
+                        '    <meta property="article:tag" content="tag3" />\n' +
+                        '    <meta name="generator" content="Ghost 0.3" />\n' +
+                        '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
 
                 done();
             }).catch(done);
@@ -593,9 +625,9 @@ describe('Core Helpers', function () {
             config.set({url: 'http://testurl.com/blog/'});
             helpers.ghost_head.call({version: '0.3.0'}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.3" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/blog/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/blog/rss/">\n' +
+                    '    <meta name="generator" content="Ghost 0.3" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/blog/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/blog/rss/" />');
 
                 done();
             }).catch(done);
@@ -605,9 +637,9 @@ describe('Core Helpers', function () {
             config.set({url: 'http://testurl.com'});
             helpers.ghost_head.call({version: '0.3.0', relativeUrl: '/about/'}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.3" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/about/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/">\n' +
+                    '    <meta name="generator" content="Ghost 0.3" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/about/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
 
                 done();
             }).catch(done);
@@ -617,11 +649,11 @@ describe('Core Helpers', function () {
             config.set({url: 'http://testurl.com'});
             helpers.ghost_head.call({version: '0.3.0', relativeUrl: '/page/3/', pagination: {next: '4', prev: '2'}}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.3" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/page/3/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/">\n' +
+                    '    <link rel="prev" href="http://testurl.com/page/2/" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/page/3/" />\n' +
+                    '    <link rel="next" href="http://testurl.com/page/4/" />\n' +
-                    '<link rel="prev" href="http://testurl.com/page/2/" />\n' +
+                    '    <meta name="generator" content="Ghost 0.3" />\n' +
-                    '<link rel="next" href="http://testurl.com/page/4/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
                 done();
             }).catch(done);
         });
@@ -630,11 +662,11 @@ describe('Core Helpers', function () {
             config.set({url: 'http://testurl.com'});
             helpers.ghost_head.call({version: '0.3.0', relativeUrl: '/page/2/', pagination: {next: '3', prev: '1'}}).then(function (rendered) {
                 should.exist(rendered);
-                rendered.string.should.equal('<meta name="generator" content="Ghost 0.3" />\n' +
+                rendered.string.should.equal('<link rel="canonical" href="http://testurl.com/page/2/" />\n' +
-                    '<link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/">\n' +
+                    '    <link rel="prev" href="http://testurl.com/" />\n' +
-                    '<link rel="canonical" href="http://testurl.com/page/2/" />\n' +
+                    '    <link rel="next" href="http://testurl.com/page/3/" />\n' +
-                    '<link rel="prev" href="http://testurl.com/" />\n' +
+                    '    <meta name="generator" content="Ghost 0.3" />\n' +
-                    '<link rel="next" href="http://testurl.com/page/3/" />');
+                    '    <link rel="alternate" type="application/rss+xml" title="Ghost" href="/rss/" />');
                 done();
             }).catch(done);
         });