Attachments transform

README.md

@@ -180,7 +180,43 @@ export default Ember.Route.extend({
     }
   }
 });
+```
+
+## Attachments
+
+`Ember-Pouch` provides an `attachment` transform for your models, which makes working with attachments as simple as working with any other field.
+
+Add a `DS.attr('attachment')` field to your model. Provide a default value for it to be an empty array.
+
+```js
+// myapp/models/photo-album.js
+export default DS.Model.extend({
+  photos: DS.attr('attachment', {
+    defaultValue: function() {
+      return [];
+    }
+  });
+});
+```
 
+Here, instances of `PhotoAlbum` have a `photos` field, which is an array of plain `Ember.Object`s, which have a `.name` and `.content_type`. Non-stubbed attachment also have a `.data` field; and stubbed attachments have a `.stub` instead.
+```handlebars
+<ul>
+  {{#each myalbum.photos as |photo|}}
+    <li>{{photo.name}}</li>
+  {{/each}}
+</ul>
+```
+
+Attach new files by adding an `Ember.Object` with a `.name`, `.content_type` and `.data` to array of attachments. 
+
+```js
+// somewhere in your controller/component:
+myAlbum.get('photos').addObject(Ember.Object.create({
+  'name': 'kitten.jpg',
+  'content_type': 'image/jpg',
+  'data': btoa('hello world') // base64-encoded `String`, or a DOM `Blob`, or a `File`
+}));
 ```
 
 ## Sample app

addon/transforms/attachment.js

@@ -0,0 +1,41 @@
+import Ember from 'ember';
+import DS from 'ember-data';
+
+const { isNone } = Ember;
+const keys = Object.keys || Ember.keys;
+
+export default DS.Transform.extend({
+  deserialize: function(serialized) {
+    if (isNone(serialized)) { return []; }
+
+    return keys(serialized).map(function (attachmentName) {
+      return Ember.Object.create({
+        name: attachmentName,
+        content_type: serialized[attachmentName]['content_type'],
+        data: serialized[attachmentName]['data'],
+        stub: serialized[attachmentName]['stub'],
+        length: serialized[attachmentName]['length'],
+        digest: serialized[attachmentName]['digest']
+      });
+    });
+  },
+
+  serialize: function(deserialized) {
+    if (!Ember.isArray(deserialized)) { return null; }
+
+    return deserialized.reduce(function (acc, attachment) {
+      const serialized = {
+        content_type: attachment.get('content_type'),
+      };
+      if (attachment.get('stub')) {
+        serialized.stub = true;
+        serialized.length = attachment.get('length');
+        serialized.digest = attachment.get('digest');
+      } else {
+        serialized.data = attachment.get('data');
+      }
+      acc[attachment.get('name')] = serialized;
+      return acc;
+    }, {});
+  }
+});

app/transforms/attachment.js

@@ -0,0 +1 @@
+export { default } from 'ember-pouch/transforms/attachment';

tests/unit/transforms/attachment-test.js

@@ -0,0 +1,74 @@
+import { moduleFor, test } from 'ember-qunit';
+
+import Ember from 'ember';
+
+let testSerializedData = {
+  'hello.txt': {
+    content_type: 'text/plain',
+    data: 'aGVsbG8gd29ybGQ=',
+    digest: "md5-7mkg+nM0HN26sZkLN8KVSA=="
+    // CouchDB doesn't add 'length'
+  },
+  'stub.txt': {
+    stub: true,
+    content_type: 'text/plain',
+    digest: "md5-7mkg+nM0HN26sZkLN8KVSA==",
+    length: 11
+  },
+};
+
+let testDeserializedData = [
+  Ember.Object.create({
+    name: 'hello.txt',
+    content_type: 'text/plain',
+    data: 'aGVsbG8gd29ybGQ=',
+    digest: 'md5-7mkg+nM0HN26sZkLN8KVSA=='
+  }),
+  Ember.Object.create({
+    name: 'stub.txt',
+    content_type: 'text/plain',
+    stub: true,
+    digest: 'md5-7mkg+nM0HN26sZkLN8KVSA==',
+    length: 11
+  })
+];
+
+moduleFor('transform:attachment', 'Unit | Transform | attachment', {});
+
+test('it serializes an attachment', function(assert) {
+  let transform = this.subject();
+  assert.equal(transform.serialize(null), null);
+  assert.equal(transform.serialize(undefined), null);
+  assert.deepEqual(transform.serialize([]), {});
+
+  let serializedData = transform.serialize(testDeserializedData);
+
+  let hello = testDeserializedData[0].get('name');
+  assert.equal(hello, 'hello.txt');
+  assert.equal(serializedData[hello].content_type, testSerializedData[hello].content_type);
+  assert.equal(serializedData[hello].data, testSerializedData[hello].data);
+
+  let stub = testDeserializedData[1].get('name');
+  assert.equal(stub, 'stub.txt');
+  assert.equal(serializedData[stub].content_type, testSerializedData[stub].content_type);
+  assert.equal(serializedData[stub].stub, true);
+});
+
+test('it deserializes an attachment', function(assert) {
+  let transform = this.subject();
+  assert.deepEqual(transform.deserialize(null), []);
+  assert.deepEqual(transform.deserialize(undefined), []);
+
+  let deserializedData = transform.deserialize(testSerializedData);
+
+  assert.equal(deserializedData[0].get('name'), testDeserializedData[0].get('name'));
+  assert.equal(deserializedData[0].get('content_type'), testDeserializedData[0].get('content_type'));
+  assert.equal(deserializedData[0].get('data'), testDeserializedData[0].get('data'));
+  assert.equal(deserializedData[0].get('digest'), testDeserializedData[0].get('digest'));
+
+  assert.equal(deserializedData[1].get('name'), testDeserializedData[1].get('name'));
+  assert.equal(deserializedData[1].get('content_type'), testDeserializedData[1].get('content_type'));
+  assert.equal(deserializedData[1].get('stub'), true);
+  assert.equal(deserializedData[1].get('digest'), testDeserializedData[1].get('digest'));
+  assert.equal(deserializedData[1].get('length'), testDeserializedData[1].get('length'));
+});