Objective of the demo: You have a website with users, and those users can write comments. Add REST API to the backend for a new feature: the possibility for users to rate comments written by other users.

Create 2 REST endpoints:

• One to rate a comment (a rating is a thumb up or a thumb down).
• One to get the total score (sum of ratings) for a comment.

We will have two tables in mysql (user and comment) and will save score comment in redis database.

To resolve this problem is enough with mysql database (create new table M:N for score comments), but this is only an example how use NoSql database and RDBMS in symfony project.

To save score comments we will use sets, where the key of set will be rating:{commentId} and members of the set following next format {userId:score}.

Example:

smembers rating:1

It will return,

1) "5:1"
2) "3:1"
3) "2:1"
4) "4:-1"

For sure you can resolve score comments using different structure and strategy, this is only an example.

• Use interfaces to get soft dependencies.
• Keep your business logic outside bundles.
• Keep your model decoupled from the framework and ORM.
• Keep mapping and validation configuration outside entity classes so do not use annotations in the model.
• Annotate your controller, Example: 'routing', 'security', 'template', 'cache', 'apidoc', ...

• Business cases
• Repositories
• Services
• Controllers
• Value objects

(*) When I have time I will do the same demo application with DDD architecture.

In this layer should be saved logic of the product, you can have dependencies like repositories, services, components or value objects, but you never can have dependency with another business case.

Dependencies allowed:

• Services
• Value Objects
• External libraries

No dependencies allowed:

• Business cases

(*) Important: never inject object like session in this layer. Business cases are used in controllers but as well in commands where sessions make not sense.

Usually you will use this layer with Doctrine ORM, redis, file system ... In this layer only will manipulate data but never will have business logic.

Dependencies allowed:

• Services (*)
• Value Objects
• External libraries

No dependencies allowed:

• Business cases
• Services
• Repositories

(*) Only specific service like cache service, log, redis service or something similar.

In this layer you will encapsulate funcionalities not directly related with logic business (Business cases): send emails, logs, cache, export files, ...

Dependencies allowed:

• Services
• Repositories
• Value Objects
• External libraries

No dependencies allowed:

• Business cases

Methods in controllers should be small and don`t include business logic. Only will have small logic to handle the response but never business logic.

Like general rule only should call in controller business case layer, but some times you will not need business logic in controller, for example when your controller return a specific object (GET /comment/{id}/rating), in these case is allowed use repositories.

To save values like constants or similar things and not match directly with entity in database. Example: ErrorCode, VoteAction, ...

Like general rule should be tested layers like custom services, business cases.

• Business cases
• Custom Services

If you have value objects or components with logic you should test them.

Depends of the project can be tested controllers using functional, commands or repositories with integration tests but we need evaluate these posibilities in each case, and you must think about costs of integration and functional test (E2E), usually they have high maintenance and if you are using CI environment operations people will have extra work :-)

In this demo application I did integration test with class RedisRatingRepository because is a repository to handle data with specific structure of data in redis. Repositories from Doctrine is not necessary to test them.

The repository RedisRatingRepository use redis command sadd and srem.

You can execute command,

redis-benchmark -t sadd -n 100000 -q

You will get the next result,

SADD: 66137.57 requests per second

That result was got in vagrant machine with Debian, 4096MB and 2 cores.

Add http://demo.local like a virtual host in your local machine

• composer install
• ./app/console doctrine:database:create --env=dev
• ./app/console doctrine:schema:create --env=dev
• bash ./app/console doctrine:fixtures:load --fixtures src/AppBundle/DataFixtures/Doctrine/ORM
• php ./app/console api:doc:dump

./bin/phpunit -c app/ --coverage-text or ./bin/phpunit -c app/ --coverage-html ./build

http://demo.local/app_dev.php/api/doc

Get total score comment:

• http://demo.local/app_dev.php/comment/{id}/rating [GET]

Create score comment (UP or DOWN):

• http://demo.local/app_dev.php/comment/{id}/rating [POST]

You can test API rest in your local using sandbox enabled in API doc or using postman.

To test API Rest you can use sandbox enabled in (http://demo.local/app_dev.php/api/doc)

Import file rest.postman_collection.json in postman application.

Request

Method GET

http://demo.local/app_dev.php/comment/1/rating

Response

Status 200

5

Where 5 is total score to comment ID = 1.

Request

Method GET

http://demo.local/app_dev.php/comment/30/rating

Where comment ID = 30 does not exist.

Response

Status 404

{
  "Errors": [
    "Comment does not exist"
  ],
  "ErrorCode": 20,
  "TotalErrors": 1
}

Request

Method POST

http://demo.local/app_dev.php/comment/1/rating

With body:

{"userId": 5, "score": -1}

Response

Status 200

{
  "Comment": {
    "Id": 1,
    "Text": "Aut debitis natus beatae consectetur ea. Tempora voluptate veniam illum reprehenderit et voluptatibus minima. Facilis numquam voluptate sint. Quos eaque amet quisquam eligendi.\nFacilis ex magnam qui et aliquam. Eum aut nisi excepturi aut non. Magnam delectus nam commodi praesentium sit.",
    "CreatedAt": "1984-05-19T10:55:10+0200",
    "UpdatedAt": "2009-03-16T22:44:51+0100",
    "User": {
      "Id": 1,
      "Name": "Cloyd",
      "CreatedAt": "1978-03-26T22:12:16+0100",
      "UpdatedAt": "1998-05-27T19:39:48+0200"
    }
  },
  "Votes": {
    "2": {
      "UserId": 2,
      "Score": 1
    },
    "5": {
      "UserId": 5,
      "Score": -1
    }
  }
}

Request

Method POST

http://demo.local/app_dev.php/comment/1/rating

With body:

{"userId": 2, "score": 10}

Response

Status 400

{
  "Errors": {
    "score": "Invalid '10' provided."
  },
  "ErrorCode": 10,
  "TotalErrors": 1
}

Only are valid values 1 or -1 to score field.

Request

Method POST

http://demo.local/app_dev.php/comment/50/rating

With body:

{"userId": 2, "score": -1}

Where comment ID = 50 does not exist.

Response

Status 400

{
  "Errors": [
    "Comment does not exist"
  ],
  "ErrorCode": 40,
  "TotalErrors": 1
}

Request

Method POST

http://demo.local/app_dev.php/comment/1/rating

With body:

{"userId": 2, "score": -1}

Where user ID = 2 put score in the past.

Response

Status 400

{
  "Errors": [
    "User 2 already vote"
  ],
  "ErrorCode": 50,
  "TotalErrors": 1
}

Request

Method POST

http://demo.local/app_dev.php/comment/1/rating

With body:

{"userId": 1, "score": -1}

Where user ID = 1 is the author of comment

Response

Status 400

{
  "Errors": [
    "You can not vote your own comment"
  ],
  "ErrorCode": 50,
  "TotalErrors": 1
}

Request

Method POST

http://demo.local/app_dev.php/comment/1/rating

With body:

{"userId": 1, "score": -1

Where the body is bad json format

Response

Status 400

{
  "Errors": [
    "unexpected end of data, ErrorCode: 4"
  ],
  "ErrorCode": 10,
  "TotalErrors": 1
}

Symfony2 coding standard, you can get here https://github.com/djoos/Symfony2-codingstandard.git:

And execute command:

./bin/phpcs --extensions=php --colors --standard=/path/Symfony2-coding-standard_data/Symfony2 ./src