feat: add option to fetch content available in all files (#27, fix #22)

* add missing doc

* feat: add common content to all entries

no tests yet, just proof of concept

refs #22

* test for previous commit's work on #22

* add docs for common queries

refs #22

also fix up older doc a lil bit

* improve comments, refs #22

* provide a template usage example and fix syntax in other example

* use options directly instead of useless extra var definitions

* use similar arg ordering to other functions

* note about hbs syntax

* transform the query just for convenience

docs/global-settings.md

@@ -72,7 +72,7 @@ You can then use the keyword `__NOW__` in your source file's `filter` values, li
 
 ```markdown
 ---
-title: Post overview of entries including "rabbit"
+title: Articles with certain start and end dates
 contentful:
   content_type: post
   filter:
@@ -81,3 +81,29 @@ contentful:
 layout: posts.html
 ---
 ```
+
+### `common` *(optional)*
+
+The results of queries placed in this property will be made available in all templates
+
+For example, find your five latest entries so you can include them in various templates:
+
+```javascript
+{
+  // ...
+  "common": {
+    "latest": {
+      "content_type": "post",
+      "limit": 5,
+      "order": "sys.createdAt"
+    }
+  },
+  // ...
+}
+```
+
+In templates you can then access `common.latest` to get the raw results of the above query:
+
+```
+The first latest post's title, in handlebars syntax: {{ common.latest.items.0.fields.title }}
+```

lib/processor.js

@@ -10,6 +10,7 @@ const clients = {}
  *
  * @param  {String} accessToken access token
  * @param  {String} spaceId     space id
+ * @param  {String} host        host
  *
  * @return {Object}             contentful client
  */
@@ -25,6 +26,48 @@ function getContentfulClient (accessToken, spaceId, host) {
   return clients[spaceId]
 }
 
+/**
+ * Fetch common content for a certain space.
+ *
+ * @param {Object} entries entries fetched from contentful
+ * @param {Object} options plugin config
+ *
+ * @return {Object}        file mapping object with common content added
+ */
+function getCommonContentForSpace (entries, options) {
+  if (!options.common) {
+    return entries
+  }
+
+  const client = getContentfulClient(options.access_token, options.space_id, options.host)
+
+  const commonQueries = []
+  const commonIds = []
+
+  for (let id in options.common) {
+    commonQueries.push(client.getEntries(util.getEntriesQuery(options.common[id], options.filterTransforms)))
+    commonIds.push(id)
+  }
+
+  // First, execute all common queries.
+  return Promise.all(commonQueries).then(commonContent => {
+    return new Promise((resolve, reject) => {
+      // Store the results in an object using the configured IDs.
+      const commonsObj = commonIds.reduce((prev, curr, index) => {
+        prev[curr] = commonContent[index]
+        return prev
+      }, {})
+
+      // Assign common query results to each entry.
+      for (let entry in entries) {
+        entries[entry].common = commonsObj
+      }
+
+      resolve(entries)
+    })
+  })
+}
+
 /**
  * Enrich all fetched entries with additional properties
  *
@@ -121,6 +164,7 @@ function processFile (file, options) {
   return client.getEntries(query)
     .then(entries => mapEntriesForFile(entries.items, file, options))
     .then(entries => processEntriesForFile(file, entries))
+    .then(entries => getCommonContentForSpace(entries, options))
 }
 
 module.exports = {

lib/processor.spec.js

@@ -207,3 +207,65 @@ test('processor.processFile - resolves correctly for multiple entries', t => {
     )
   })
 })
+
+test('processor.getCommonContentForSpace - load a set of common content', t => {
+  const options = {
+    access_token: 'global-bar',
+    host: 'global-baz',
+    space_id: 'global-foo',
+    common: {
+      doublets: {
+        filter: 'mulledwine'
+      }
+    }
+  }
+
+  const entriesToBeReturned = [
+    {
+      sys: {
+        id: 'bazinga',
+        contentType: {
+          sys: {
+            id: 'boing'
+          }
+        }
+      },
+      fields: {
+        name: 'John Doe'
+      }
+    },
+    {
+      sys: {
+        id: 'badabum',
+        contentType: {
+          sys: {
+            id: 'kazum'
+          }
+        }
+      },
+      fields: {
+        name: 'Jane Doe'
+      }
+    }
+  ]
+
+  const processor = proxyquire(
+    './processor',
+    {
+      contentful: {
+        createClient: function () {
+          return {
+            getEntries: function () {
+              return new Promise(resolve => resolve({items: entriesToBeReturned}))
+            }
+          }
+        }
+      }
+    }
+  )
+
+  processor.processFile({ contentful: {}, _fileName: 'turnip.html' }, options)
+  .then(fileMap => {
+    t.is(fileMap['turnip.html'].common.doublets, entriesToBeReturned)
+  })
+})