[API] Retrieve next and previous post

closes #4262
- implementation based on #1545
- added integration test. Modified mocked posts because code requires published_at timestamps to be different.
- fixed 2 broken tests that depended on mocked posts to have "new Date()" as their timestamps
- added checks to only query db if next/previous post requested

Author: ekulabuhov

core/server/api/posts.js

@@ -8,7 +8,7 @@ var Promise         = require('bluebird'),
     utils           = require('./utils'),
 
     docName         = 'posts',
-    allowedIncludes = ['created_by', 'updated_by', 'published_by', 'author', 'tags', 'fields'],
+    allowedIncludes = ['created_by', 'updated_by', 'published_by', 'author', 'tags', 'fields', 'next', 'previous'],
     posts;
 
 // ## Helpers

core/server/models/post.js

@@ -525,6 +525,9 @@ Post = ghostBookshelf.Model.extend({
     findOne: function (data, options) {
         options = options || {};
 
+        var withNext = _.contains(options.include, 'next'),
+            withPrev = _.contains(options.include, 'previous');
+
         data = _.extend({
             status: 'published'
         }, data || {});
@@ -533,10 +536,50 @@ Post = ghostBookshelf.Model.extend({
             delete data.status;
         }
 
-        // Add related objects
-        options.withRelated = _.union(options.withRelated, options.include);
+        // Add related objects, excluding next and previous as they are not real db objects
+        options.withRelated = _.union(options.withRelated, _.pull([].concat(options.include), 'next', 'previous'));
+
+        return ghostBookshelf.Model.findOne.call(this, data, options).then(function (post) {
+            if ((withNext || withPrev) && post && !post.page) {
+                var postData = post.toJSON(),
+                    publishedAt = postData.published_at,
+                    prev,
+                    next;
+
+                if (withNext) {
+                    next = Post.forge().query(function (qb) {
+                        qb.where('status', '=', 'published')
+                            .andWhere('page', '=', 0)
+                            .andWhere('published_at', '>', publishedAt)
+                            .orderBy('published_at', 'asc')
+                            .limit(1);
+                    }).fetch();
+                }
+
+                if (withPrev) {
+                    prev = Post.forge().query(function (qb) {
+                        qb.where('status', '=', 'published')
+                            .andWhere('page', '=', 0)
+                            .andWhere('published_at', '<', publishedAt)
+                            .orderBy('published_at', 'desc')
+                            .limit(1);
+                    }).fetch();
+                }
 
-        return ghostBookshelf.Model.findOne.call(this, data, options);
+                return Promise.join(next, prev)
+                    .then(function (nextAndPrev) {
+                        if (nextAndPrev[0]) {
+                            post.relations.next = nextAndPrev[0];
+                        }
+                        if (nextAndPrev[1]) {
+                            post.relations.previous = nextAndPrev[1];
+                        }
+                        return post;
+                    });
+            }
+
+            return post;
+        });
     },
 
     /**

core/test/functional/routes/api/posts_test.js

@@ -235,6 +235,32 @@ describe('Post API', function () {
                 });
         });
 
+        it('can retrieve next and previous posts', function (done) {
+            request.get(testUtils.API.getApiQuery('posts/3/?include=next,previous'))
+                .set('Authorization', 'Bearer ' + accesstoken)
+                .expect('Content-Type', /json/)
+                .expect('Cache-Control', testUtils.cacheRules['private'])
+                .expect(200)
+                .end(function (err, res) {
+                    if (err) {
+                        return done(err);
+                    }
+
+                    should.not.exist(res.headers['x-cache-invalidate']);
+                    var jsonResponse = res.body;
+                    jsonResponse.should.exist;
+                    jsonResponse.posts.should.exist;
+                    testUtils.API.checkResponse(jsonResponse.posts[0], 'post', ['next', 'previous']);
+                    jsonResponse.posts[0].page.should.not.be.ok;
+
+                    jsonResponse.posts[0].next.should.be.an.Object;
+                    testUtils.API.checkResponse(jsonResponse.posts[0].next, 'post');
+                    jsonResponse.posts[0].previous.should.be.an.Object;
+                    testUtils.API.checkResponse(jsonResponse.posts[0].previous, 'post');
+                    done();
+                });
+        });
+
         it('can retrieve a static page', function (done) {
             request.get(testUtils.API.getApiQuery('posts/7/'))
                 .set('Authorization', 'Bearer ' + accesstoken)

core/test/integration/model/model_posts_spec.js

@@ -162,7 +162,7 @@ describe('Post Model', function () {
 
         it('can findOne, returning a dated permalink', function (done) {
             var firstPost = 1,
-                today = new Date(),
+                today = testUtils.DataGenerator.Content.posts[0].published_at,
                 dd = ('0' + today.getDate()).slice(-2),
                 mm = ('0' + (today.getMonth() + 1)).slice(-2),
                 yyyy = today.getFullYear(),

core/test/unit/config_spec.js

@@ -242,7 +242,7 @@ describe('Config', function () {
             var permalinkSetting = '/:year/:month/:day/:slug/',
                 /*jshint unused:false*/
                 testData = testUtils.DataGenerator.Content.posts[2],
-                today = new Date(),
+                today = testData.published_at,
                 dd = ('0' + today.getDate()).slice(-2),
                 mm = ('0' + (today.getMonth() + 1)).slice(-2),
                 yyyy = today.getFullYear(),

core/test/utils/fixtures/data-generator.js

@@ -9,18 +9,21 @@ DataGenerator.Content = {
         {
             title: "HTML Ipsum",
             slug: "html-ipsum",
-            markdown: "<h1>HTML Ipsum Presents</h1><p><strong>Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. <em>Aenean ultricies mi vitae est.</em> Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, <code>commodo vitae</code>, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. <a href=\"#\">Donec non enim</a> in turpis pulvinar facilisis. Ut felis.</p><h2>Header Level 2</h2><ol><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ol><blockquote><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est.</p></blockquote><h3>Header Level 3</h3><ul><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ul><pre><code>#header h1 a{display: block;width: 300px;height: 80px;}</code></pre>"
+            markdown: "<h1>HTML Ipsum Presents</h1><p><strong>Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. <em>Aenean ultricies mi vitae est.</em> Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, <code>commodo vitae</code>, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. <a href=\"#\">Donec non enim</a> in turpis pulvinar facilisis. Ut felis.</p><h2>Header Level 2</h2><ol><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ol><blockquote><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est.</p></blockquote><h3>Header Level 3</h3><ul><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ul><pre><code>#header h1 a{display: block;width: 300px;height: 80px;}</code></pre>",
+            published_at: new Date("2015-01-01")
         },
         {
             title: "Ghostly Kitchen Sink",
             slug: "ghostly-kitchen-sink",
-            markdown: "<h1>HTML Ipsum Presents</h1><p><strong>Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. <em>Aenean ultricies mi vitae est.</em> Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, <code>commodo vitae</code>, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. <a href=\"#\">Donec non enim</a> in turpis pulvinar facilisis. Ut felis.</p><h2>Header Level 2</h2><ol><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ol><blockquote><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est.</p></blockquote><h3>Header Level 3</h3><ul><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ul><pre><code>#header h1 a{display: block;width: 300px;height: 80px;}</code></pre>"
+            markdown: "<h1>HTML Ipsum Presents</h1><p><strong>Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. <em>Aenean ultricies mi vitae est.</em> Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, <code>commodo vitae</code>, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. <a href=\"#\">Donec non enim</a> in turpis pulvinar facilisis. Ut felis.</p><h2>Header Level 2</h2><ol><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ol><blockquote><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est.</p></blockquote><h3>Header Level 3</h3><ul><li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li><li>Aliquam tincidunt mauris eu risus.</li></ul><pre><code>#header h1 a{display: block;width: 300px;height: 80px;}</code></pre>",
+            published_at: new Date("2015-01-02")
         },
         {
             title: "Short and Sweet",
             slug: "short-and-sweet",
             markdown: "## testing\n\nmctesters\n\n- test\n- line\n- items",
-            html: "<h2 id=\"testing\">testing</h2>\n\n<p>mctesters</p>\n\n<ul>\n<li>test</li>\n<li>line</li>\n<li>items</li>\n</ul>"
+            html: "<h2 id=\"testing\">testing</h2>\n\n<p>mctesters</p>\n\n<ul>\n<li>test</li>\n<li>line</li>\n<li>items</li>\n</ul>",
+            published_at: new Date("2015-01-03")
         },
         {
             title: "Not finished yet",