add deserialize method

Author: danivek

README.md

@@ -1,7 +1,7 @@
 # json-api-serializer
 [![Build Status](https://travis-ci.org/danivek/json-api-serializer.svg?branch=master)](https://travis-ci.org/danivek/json-api-serializer)
 [![Coverage Status](https://coveralls.io/repos/github/danivek/json-api-serializer/badge.svg?branch=master)](https://coveralls.io/github/danivek/json-api-serializer?branch=master)
-[![npm](https://img.shields.io/npm/v/json-api-serializer.svg?maxAge=2592000)](https://www.npmjs.org/package/json-api-serializer)
+[![npm](https://img.shields.io/npm/v/json-api-serializer.svg)](https://www.npmjs.org/package/json-api-serializer)
 
 A Node.js framework agnostic library for serializing your data to [JSON API](http://jsonapi.org/) compliant responses (a specification for building APIs in JSON).
 
@@ -38,11 +38,13 @@ Serializer.register(type, options);
         - **alternativeKey** (optional): An alternative key to use if relationship key not exist (example: 'author_id' as an alternative key for 'author' relationship). See [issue #12](https://github.com/danivek/json-api-serializer/issues/12).
         - **schema** (optional): A custom schema for serializing the relationship. If no schema define, it use the default one.
         - **links** (optional): An *object* or a *function* that describes the links for the relationship. (If it is an object values can be string or function).
-- **convertCase** (optional): Case conversion for outputted data. Value can be : `kebab-case`, `snake_case`, `camelCase`
+- **convertCase** (optional): Case conversion for serializing data. Value can be : `kebab-case`, `snake_case`, `camelCase`
+- **unconvertCase** (optional): Case conversion for deserializing data. Value can be : `kebab-case`, `snake_case`, `camelCase`
+
 
 ## Usage
 
-input data (can be a simple object or an array of objects)
+input data (can be an object or an array of objects)
 ```javascript
 // Data
 var data = {
@@ -77,6 +79,7 @@ var data = {
 }
 ```
 
+### Register
 Register your resources types :
 ```javascript
 var JSONAPISerializer = require('json-api-serializer');
@@ -149,6 +152,8 @@ Serializer.register('comment', 'only-body', {
 });
 ```
 
+### Serialize
+
 Serialize it with the corresponding resource type, data and optional extra options :
 
 ```javascript
@@ -260,6 +265,56 @@ The output data will be :
 ```
 Some others examples are available in [ tests folders](https://github.com/danivek/json-api-serializer/blob/master/test/)
 
+### Deserialize
+
+```javascript
+var data = {
+  data: {
+    type: 'article',
+    id: '1',
+    attributes: {
+      title: 'JSON API paints my bikeshed!',
+      body: 'The shortest article. Ever.',
+      created: '2015-05-22T14:56:29.000Z'
+    },
+    relationships: {
+      author: {
+        data: {
+          type: 'people',
+          id: '1'
+        }
+      },
+      comments: {
+        data: [{
+          type: 'comment',
+          id: '1'
+        }, {
+          type: 'comment',
+          id: '2'
+        }]
+      }
+    }
+  }
+};
+
+Serializer.deserialize('article', data);
+```
+
+```JSON
+{
+  "id": "1",
+  "title": "JSON API paints my bikeshed!",
+  "body": "The shortest article. Ever.",
+  "created": "2015-05-22T14:56:29.000Z",
+  "author": "1",
+  "comments": [
+    "1",
+    "2"
+  ]
+}
+```
+
+
 ## Custom schemas
 
 It is possible to define multiple custom schemas for a resource type :
@@ -268,10 +323,11 @@ It is possible to define multiple custom schemas for a resource type :
 Serializer.register(type, 'customSchema', options);
 ```
 
-If you want to apply this schema on the primary data :
+Then you can apply this schema on the primary data when serialize or deserialize :
 
 ```javascript
 Serializer.serialize('article', data, 'customSchema', {count: 2});
+Serializer.deserialize('article', jsonapiData, 'customSchema');
 ```
 
 Or if you want to apply this schema on a relationship data, define this schema on relationships options with the key `schema` :

lib/JSONAPISerializer.js

@@ -44,6 +44,7 @@ module.exports = class JSONAPISerializer {
       topLevelLinks: joi.alternatives([joi.func(), joi.object()]).default({}),
       topLevelMeta: joi.alternatives([joi.func(), joi.object()]).default({}),
       convertCase: joi.string().valid('kebab-case', 'snake_case', 'camelCase'),
+      unconvertCase: joi.string().valid('kebab-case', 'snake_case', 'camelCase'),
     }).required();
 
     const validated = joi.validate(options, optionsSchema);
@@ -121,6 +122,60 @@ module.exports = class JSONAPISerializer {
     };
   }
 
+  /**
+   * Deserialize JSON API document data.
+   * Input data can be a simple object or an array of objects.
+   *
+   * @method JSONAPISerializer#deserialize
+   * @param {string} type resource's type.
+   * @param {Object} data JSON API input data.
+   * @param {string} [schema=default] resource's schema name.
+   * @return {Object} deserialized data.
+   */
+  deserialize(type, data, schema) {
+    schema = schema || 'default';
+
+    if (!this.schemas[type]) {
+      throw new Error('No type registered for ' + type);
+    }
+
+    if (schema && !this.schemas[type][schema]) {
+      throw new Error('No schema ' + schema + ' registered for ' + type);
+    }
+
+    const resourceOpts = this.schemas[type][schema];
+    let deserializedData = {};
+
+    if (data.data) {
+      // Deserialize id
+      deserializedData[resourceOpts.id] = data.data.id || undefined;
+
+      // Deserialize attributes
+      Object.assign(deserializedData, data.data.attributes);
+
+      // Deserialize relationships
+      _.forOwn(data.data.relationships, (value, relationship) => {
+        // Support alternativeKey options for relationships
+        let relationshipKey = relationship;
+        if (resourceOpts.relationships[relationshipKey] && resourceOpts.relationships[relationshipKey].alternativeKey) {
+          relationshipKey = resourceOpts.relationships[relationshipKey].alternativeKey;
+        }
+
+        if (_.isArray(value.data)) {
+          deserializedData[relationshipKey] = value.data.map((d) => d.id);
+        } else {
+          deserializedData[relationshipKey] = value.data.id;
+        }
+      });
+
+      if (resourceOpts.unconvertCase) {
+        deserializedData = this._convertCase(deserializedData, resourceOpts.unconvertCase);
+      }
+    }
+
+    return deserializedData;
+  }
+
   /**
    * Serialize resource objects.
    *

test/unit/JSONAPISerializer.test.js

@@ -623,9 +623,9 @@ describe('JSONAPISerializer', function() {
       });
 
       const data = {
-        id: "1",
-        title: "JSON API paints my bikeshed!",
-        body: "The shortest article. Ever."
+        id: '1',
+        title: 'JSON API paints my bikeshed!',
+        body: 'The shortest article. Ever.'
       };
 
       const serializedData = Serializer.serialize('articles', data, 'only-title');
@@ -652,4 +652,157 @@ describe('JSONAPISerializer', function() {
       done();
     });
   });
+
+  describe('deserialize', function() {
+    it('should deserialize data with relationships', function(done) {
+      const Serializer = new JSONAPISerializer();
+      Serializer.register('articles', {});
+
+      const data = {
+        data: {
+          type: 'article',
+          id: '1',
+          attributes: {
+            title: 'JSON API paints my bikeshed!',
+            body: 'The shortest article. Ever.',
+            created: '2015-05-22T14:56:29.000Z'
+          },
+          relationships: {
+            author: {
+              data: {
+                type: 'people',
+                id: '1'
+              }
+            },
+            comments: {
+              data: [{
+                type: 'comment',
+                id: '1'
+              }, {
+                type: 'comment',
+                id: '2'
+              }]
+            }
+          }
+        }
+      };
+
+      const deserializedData = Serializer.deserialize('articles', data);
+      expect(deserializedData).to.have.property('id');
+      expect(deserializedData).to.have.property('title');
+      expect(deserializedData).to.have.property('body');
+      expect(deserializedData).to.have.property('created');
+      expect(deserializedData).to.have.property('author', '1');
+      expect(deserializedData).to.have.property('comments').to.be.instanceof(Array).to.eql(['1', '2']);
+      done();
+    });
+
+    it('should deserialize with \'id\' options', function(done) {
+      const Serializer = new JSONAPISerializer();
+      Serializer.register('articles', {
+        id: '_id'
+      });
+
+      const data = {
+        data: {
+          type: 'article',
+          id: '1',
+          attributes: {
+            title: 'JSON API paints my bikeshed!',
+            body: 'The shortest article. Ever.',
+            created: '2015-05-22T14:56:29.000Z'
+          }
+        }
+      };
+
+      const deserializedData = Serializer.deserialize('articles', data);
+      expect(deserializedData).to.have.property('_id');
+      expect(deserializedData).to.not.have.property('id');
+      done();
+    });
+
+    it('should deserialize with \'alternativeKey\' options', function(done) {
+      const Serializer = new JSONAPISerializer();
+      Serializer.register('articles', {
+        relationships: {
+          author: {
+            type: 'people',
+            alternativeKey: 'author_id'
+          }
+        }
+      });
+
+      const data = {
+        data: {
+          type: 'article',
+          id: '1',
+          attributes: {
+            title: 'JSON API paints my bikeshed!',
+            body: 'The shortest article. Ever.',
+            created: '2015-05-22T14:56:29.000Z'
+          },
+          relationships: {
+            author: {
+              data: {
+                type: 'people',
+                id: '1'
+              }
+            }
+          }
+        }
+      };
+
+      const deserializedData = Serializer.deserialize('articles', data);
+      expect(deserializedData).to.have.property('author_id');
+      expect(deserializedData).to.not.property('author');
+      done();
+    });
+
+    it('should deserialize with \'unconvertCase\' options', function(done) {
+      const Serializer = new JSONAPISerializer();
+      Serializer.register('articles', {
+        unconvertCase: 'snake_case'
+      });
+
+      const data = {
+        data: {
+          type: 'article',
+          id: '1',
+          attributes: {
+            createdAt: '2015-05-22T14:56:29.000Z'
+          },
+          relationships: {
+            articleAuthor: {
+              data: {
+                type: 'people',
+                id: '1'
+              }
+            }
+          }
+        }
+      };
+
+      const deserializedData = Serializer.deserialize('articles', data);
+      expect(deserializedData).to.have.property('created_at');
+      expect(deserializedData).to.have.property('article_author');
+      done();
+    });
+
+    it('should throw an error if type as not been registered', function(done) {
+      expect(function() {
+        const Serializer = new JSONAPISerializer();
+        Serializer.deserialize('authors', {});
+      }).to.throw(Error, 'No type registered for authors');
+      done();
+    });
+
+    it('should throw an error if custom schema as not been registered', function(done) {
+      expect(function() {
+        const Serializer = new JSONAPISerializer();
+        Serializer.register('articles', {});
+        Serializer.deserialize('articles', {}, 'custom');
+      }).to.throw(Error, 'No schema custom registered for articles');
+      done();
+    });
+  });
 });