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warp-server

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Readme

Warp Server

Warp Server is a library for implementing the Warp Framework on Node.js. It consists of several classes which aim to produce endpoints easily accessible via a standard REST API. Currently, Warp Server uses mysql as its backend of choice and implements validators, parsers and formatters that can control the data coming in and out of the server.

Installation

To install Warp Server via npm, simply use the install command to save it in your package.json:

npm install --save warp-server

Configuration

Warp Server is built on top of express and can be initialized in any express project. To do so, simply add the following configruation to the main file of your project:

// References
var express = require('express');
var WarpServer = require('warp-server');

// Prepare config; You can also use process.env or store the config in a json file
var config = {
    security: {
        apiKey: '12345678abcdefg',
        masterKey: 'abcdefg12345678'
    },
    database: {
        host: 'localhost',
        port: 3306,
        user: 'root',
        password: 'password',
        default: 'default_table',    
    }
};

// Create a Warp Server router for the API
var api = WarpServer.initialize(config);

// Apply the Warp Server router to your preferred base URL, using express' app.use() method
var app = express();
app.use('/api/1', api);

Models

Models make it easy to define the tables found in the database. They contain special parameters which allow you to control the data that comes in and out of the server.

To define a Model, simply create a WarpServer.Model class with the following parameters:

WarpServer.Model.create({
    // Unique name assigned to the endpoint; is usally the same as the table name
    className: '{CLASS_NAME}',
    
    // If the assigned className is not the same as the table name, specify the real table name here, OPTIONAL
    source: '{SOURCE}',
    
    // Define keys/fields available in the table
    keys: {
        viewable: ['{KEY1}', '{KEY2}', '{KEY3}'], // REQUIRED: Fields viewable in queries
        actionable: ['{KEY1}', '{KEY2}', '{KEY3}'], // REQUIRED: Fields editable in queries
        
        // To define pointers (i.e. foreign key relations), declare them via the `pointers` option, OPTIONAL
        // For more info, please see section on Pointers
        pointers: {
            '{KEY2}': {
                className: '{CLASS_NAME_OF_POINTER}',
                via: '{FOREIGN_KEY}' // OPTIONAL, if `via` is not set, it is assumed to be `className`_id
            }
        },
        
        // To define file keys (i.e. fields for storing file URL's), declare them via the `files` option, OPTIONAL
        // For more info, please see section on Files
        files: ['{KEY3']
    },
    
    // Validates values that are sent to the server
    validate: {
        // User-defined validation
        '{KEY1}': function(value, key) {
            // Some validations placed here
            // If the validations fail, return a string message
            return 'Validation failed for ' + key;
            // If the validations succeed, return nothing
            return;
        },
        // Pre-defined Validation; See section on Pre-defined Validations for more info
        '{KEY2}': WarpServer.Model.Validation.FixedString(8)
    },
    
    // Parses the values received, and pushes them to the backend for saving
    parse: {
        // User-defined parser
        '{KEY1}': function(value) {
            // Conduct some changes to the value, as needed;
            // Return the parsed value
            return value;
        },
        // Pre-defined Parser; See section on Pre-defined Parsers for more info
        '{KEY2}': WarpServer.Model.Parser.Integer
    },
    
    // Formats the values requested, and pushes them to the response
    format: {
        // User-defined formatter
        '{KEY1}': function(value) {
            // Conduct some changes to the value, as needed;
            // Return the formatted value
            return value;
        },
        // Pre-defined Formatter; See section on Pre-defined Formatters for more info
        '{KEY2}': WarpServer.Model.Parser.Date
    },
    
    // Function that maniplates the keys' values before the values are saved
    beforeSave: function(keys) {
        // this.validate doesn't apply here
        // this.parse doesn't apply here
        // 'keys' is an object that contains the name of the keys and the assigned values
        // Return the keys after manipulating
        return keys;
    },
    
    // Function that executes after the values are saved
    afterSave: function(keys) {
        // this.validate doesn't apply here
        // this.parse doesn't apply here
        
        // 'keys' is an object that contains the name of the keys and the assigned values
        // Use the keys as needed
    }
});

For example, if we want to make a model for an alien table, we can write it as:

var Alien = WarpServer.Model.create({
    className: 'alien',
    keys: {
        viewable: ['name', 'age', 'type'],
        actionable: ['name', 'age', 'type']
    },
    validate: {
        'name': function(value) {
            if(value.length < 8) return 'name must be 8 or more characters';
            return;
        },
        'age': WarpServer.Model.Validation.PositiveInteger
    },
    parse: {
        'age': WarpServer.Model.Parser.Integer,
        'type': function(value) {
            switch(value)
            {
                case 0: return 'dalek';
                case 1: return 'cyberman';
                case 2: return 'zygon';
                case 3: return 'slitheen';
                case 4: return 'gallifreyan';
                default: return 'extraterrestrial';
            }
        }
    },
    beforeSave: function(keys) {
        if(keys['type'] == 'dalek' && keys['age'] > 200)
            keys['type'] = 'supreme_dalek';
            
        return keys;
    },
    afterSave: function(keys) {
        addToPapalMainframe(keys.id);
    }
});

In order to tell Warp Server to use the model we just created, we must register it before we initialize Warp Server:

// ... some config code here
WarpServer.Model.register(Alien);
var api = WarpServer.initialize(config);
// ... additional code to initialize here

We can now use the REST API to operate on alien objects. See the section regarding the REST API for more info.

Pointers

Relations are a vital aspect of Relational Databases. With regards to the Warp Server, these are represented by pointers. Pointers are keys (fields) which point to specific objects from another table. This can be thought of as the belongs_to relationship or the foreign_key relationship in SQL databases.

To specify a pointer in your Model, you may do so by adding a pointers option in your keys config:

{
    keys: {
        // Other key configurations...        
        // Pointers configuration:
        pointers: {
            '{KEY_NAME}': {
                className: '{CLASS_NAME_OF_POINTER}',
                via: '{FOREIGN_KEY}' // OPTIONAL, if not set, the foreign key is assumed to be `className`_id
            }
        } 
    }
}

So if, for example, inside our Alien model, we would like to add pointers to a Planet model. We can do so by adding the following code to our Model.create() method:

// Some code defining our model
keys: {
    viewable: ['name', 'age', 'type', 'planet'],
    actionable: ['name', 'age', 'type', 'planet'],
    pointers: {
        'planet': {
            className: 'planet',
            via: 'planet_id'
        }
    }
},
// Additional code defining our model

User and Session Models

In order to handle user authentication and management, a special type of model called the User model can be added. It is similar to the WarpServer.Model except it requires a few additional fields.

Fields required by the User Model:

username
password
email

For example, to create a User model using the user table:

var User = WarpServer.Model.create({
    className: 'user',
    keys: {
        viewable: ['username', 'email'], // Note that password should not be viewable by the REST API
        actionable: ['username', 'password', 'email']
    },
    validate: {
        // Pre-defined validators are available for the fields required by the User Model
        // See the section on Pre-defined Validators for more info.
        'username': WarpServer.Model.Validation.FixedString(8, 16),
        'password': WarpServer.Model.Validation.Password(8),
        'email': WarpServer.Model.Validation.Email
    },
    parse: {
        // Pre-defined Parsers
        // See the section on Pre-defined Parsers for more info.
        'username': WarpServer.Model.Parser.NoSpaces,
        'password': WarpServer.Model.Parser.Password
    }
});

In order for us to use the defined model as a User model, we should use .registerUser() instead of the regular .register() method:

// ... some config code here
WarpServer.Model.registerUser(User);
WarpServer.Model.register(Alien);
var api = WarpServer.initialize(config);
// ... additional code to initialize here

Aside from the User Model, we should also define a Session Model that, like the User Model, has special required fields:

user (pointer)
origin
session_token

An example of a Session Model would be as follows:

var Session = WarpServer.Model.create({
    className: 'session',
    keys: {
        viewable: ['user', 'origin', 'session_token'], // Note that the user field is a pointer to the 'user' table
        actionable: ['user', 'origin'],
        pointers: {
            'user': {
                className: 'user',
                via: 'user_id'
            }
        }
    },
    
    // In order for us to generate special session tokens, we must use the Pre-defined PreSave function.
    // For more info on these pre-defined functions, please see the secion on PreSave functions.
    beforeSave: WarpServer.Model.PreSave.Session
});

Then, we register the created model by using the .registerSession() method:

// ... some config code here
WarpServer.Model.registerUser(User);
WarpServer.Model.registerSession(Session);
WarpServer.Model.register(Alien);
var api = WarpServer.initialize(config);
// ... additional code to initialize here

We can now use the special user authentication and management operations made available by the REST API.

Files

Sometimes, you may need to upload files to your server and store them persistently. In this particular case, Warp Server helps simplify this process with the help of Warp Files. Warp Files allow you to define keys where you would want to store file-related content.

On the database side, it stores a key string which represents the file inside your desired file storage system. By default, Warp Server uses local storage, but you can define other forms of storage providers such as Amazon S3 or Azure Storage.

To specify a file in your Model, you may do so by adding a files option in your keys config:

{
    keys: {
        // Other key configurations...        
        // Files configuration:
        files: ['{KEY_NAME}']
    }
}

So if, for example, inside our Alien model, we would like to add a file named profile_pic. We can do so by adding the following code to our Model.create() method:

// Some code defining our model
keys: {
    viewable: ['name', 'age', 'type', 'planet', 'profile_pic'],
    actionable: ['name', 'age', 'type', 'planet', 'profile_pic'],
    pointers: {
        'planet': {
            className: 'planet',
            via: 'planet_id'
        }
    },
    files: ['profile_pic']
},
// Additional code defining our model

Objects

Objects represent individual instances of models. In terms of the database, an Object can be thought of as being a row in a table. Throughout the Warp Framework, Objects are the basic vehicles for data to be transmitted to and fro the server.

Each Object contains different keys which can be set or retrieved as needed. Among these keys are three special ones:

id: a unique identifier that distinguishes an object inside a table
created_at: a timestamp that records the date and time when a particular object was created (UTC)
uppdated_at: a timestamp that records the date and time when a particular object was last modified (UTC)

These keys are specifically set by the server and cannot be modified by the user.

REST API

The REST API makes it easy to handle operations being made to Objects. After initializing the server by following the instructions above, the following endpoints are readily made available for use by client-side applications.

Headers

When making HTTP requests to the REST API, it is important that the API Key is set. To do so, remember to set the X-Warp-API-Key header for your request:

X-Warp-API-Key: 12345678abcdefg

Often times, once a user has logged in, it is also important to place the X-Warp-Session-Token header in order to use certain operations only accessible to authorized users:

X-Warp-Session-Token: fhwcunf2uch20j631

Creating Objects

To create an Object for a specific model, execute a POST request to:

/classes/{CLASS_NAME}

with a JSON Object that contains the keys of your new Object:

{"{KEY1}": "{VALUE1}", "{KEY2}": "{VALUE2}"}

For example:

curl -X POST \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'Content-Type: application/json' \
--data '{"name":"The Doctor", "age": 150000, "type": 4}' \
http://localhost:3000/api/1/classes/alien

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 21,
        "name": "The Doctor",
        "age": 150000,
        "type": "gallifreyan",
        "created_at": "2016-05-12T09:18:44Z",
        "updated_at": "2016-05-12T09:18:44Z"
    }
}

Updating Objects

To update an Object for a specific model, execute a PUT request to:

/classes/{CLASS_NAME}/{ID}

with a JSON Object that contains the modified keys of your existing Object:

{"{KEY1}": "{VALUE1}", "{KEY2}": "{VALUE2}"}

For example:

curl -X PUT \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'Content-Type: application/json' \
--data '{"age": 300}' \
http://localhost:3000/api/1/classes/alien/141

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 141,
        "age": 300,
        "created_at": "2016-05-12T09:18:44Z",
        "updated_at": "2016-05-12T14:03:21Z"
    }
}

Deleting Objects

To delete an Object for a specific model, execute a DELETE request to:

/classes/{CLASS_NAME}/{ID}

For example:

curl -X DELETE \
-H 'X-Warp-API-Key: 12345678abcdefg' \
http://localhost:3000/api/1/classes/alien/29

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 29,
        "rows": 1,
        "updated_at": "2016-05-12T22:11:09Z",
        "deleted_at": "2016-05-12T22:11:09Z"
    }
}

Pointers as Keys

In order to pass pointers as keys when creating or updating an object, the keys must have a value similar to the following:

{ "type": "Pointer", "className": "{CLASS_NAME}", "id": "{ID}" }

For example:

curl -X POST \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'Content-Type: application/json' \
--data '{"name":"The Doctor", "planet": { "type": "Pointer", "className": "planet", "id": 8 }}' \
http://localhost:3000/api/1/classes/alien

Uploading Files

In order to upload files to the server, execute a POST request to:

/files/{FILE_NAME}

With multipart form data that contains a file key pointing to the desired file and a name key to set the filename:

file=@{FILE_PATH}&name={FILE_NAME}

For example:

curl -X POST \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-F 'file=@image_alien_face.jpg' \
-F 'name=image_alien_face.jpg' \
http://localhost:3000/api/1/files/image_alien_face.jpg

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "key": "20160523005923_1dUfhw81818dh1d_image_alien_face.jpg",
        "url": "http://localhost:3000/public/storage/20160523005923_1dUfhw81818dh1d_image_alien_face.jpg"
    }
}

After receiving the newly named key, you may associate this file when creating or updating an object by passing the following value:

{ "type": "File", "key": "{FILE_KEY}" }

For example:

curl -X PUT \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'Content-Type: application/json' \
--data '{"name": "Straxx", "profile_pic": { "type": "File", "key": "20160523005923_1dUfhw81818dh1d_image_alien_face.jpg" }}' \
http://localhost:3000/api/1/classes/alien/28

Deleting Files

In order to delete files from the server, execute a DELETE request to:

/files/{FILE_KEY}

For example:

curl -X DELETE \
-H 'X-Warp-API-Key: 12345678abcdefg' \
http://localhost:3000/api/1/files/20160523005923_1dUfhw81818dh1d_image_alien_face.jpg

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "key": "20160523005923_1dUfhw81818dh1d_image_alien_face.jpg",
        "deleted_at": "2016-05-12T22:11:09Z"
    }
}

Note: Make sure that before a file is deleted, all objects associated with it are disassociated.

Fetching Objects

To fetch a single Object for a specific model, execute a GET request to:

/classes/{CLASS_NAME}/{ID}

For example:

curl -X GET \
-G \
-H 'X-Warp-API-Key: 12345678abcdefg' \
http://localhost:3000/api/1/classes/alien/13

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 13,
        "name": "Wormwood",
        "age": 80,
        "type": "extraterrestrial",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T23:21:18Z"
    }
}

Queries

There are certain scenarios when you may need to find more than one Object from a model. In these instances, it would be convenient to use Queries. Queries allow you to find specific Objects based on a set of criteria.

To query Objects from a specific model, execute a GET request to:

/classes/{CLASS_NAME}

For example:

curl -X GET \
-G \
-H 'X-Warp-API-Key: 12345678abcdefg' \
http://localhost:3000/api/1/classes/alien

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": [{
        "id": 21,
        "name": "The Doctor",
        "age": 150000,
        "type": "gallifreyan",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T23:21:18Z"
    },
    {
        "id": 13,
        "name": "Wormwood",
        "age": 80,
        "type": "extraterrestrial",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T23:21:18Z"
    },
    {
        "id": 141,
        "name": "Straxx",
        "age": 300,
        "type": "extraterrestrial",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T23:21:18Z"
    }]
}

Constraints

Constraints help filter the results of a specific query. In order to pass constraints for a Query, set a where parameter with a JSON string containing all the constraints you wish to apply.

To specify constraints, you may do so using the following syntax:

{
    "{NAME_OF_KEY}": {
        "{NAME_OF_CONSTRAINT}": "{VALUE}"
    }
}

Available constraints:

eq: equal to
neq: not equal to
gt: greater than
gte: greater than or equal to
lt: less than
lte: less than or equal to
ex: is not null/is null (value is either true or false)
in: contained in array
nin: not contained in array

For example:

curl -X GET \
-G \
-H 'X-Warp-API-Key: 12345678abcdefg' \
--data-urlencoded 'where={"age": {"gte": 20}, "type": {"in": ["dalek", "gallifreyan"]}}' \
http://localhost:3000/api/1/classes/alien

Limit

By default, Warp Server limits results to the top 100 objects that satisfy the query criteria. In order to increase the limit, you can specify the desired value via the limit parameter. Also, in order to implement pagination for the results, you can combine the limit with the skip parameter. The skip parameter indicates how many items are to be skipped when executing the query. In terms of scalability, it is advisable to limit results to 1000 and use skip to determine pagination.

For example:

curl -X GET \
-G \
-H 'X-Warp-API-Key: 12345678abcdefg' \
--data-urlencoded 'limit=1000&skip=1000' \
http://localhost:3000/api/1/classes/alien

Sorting

Sorting determines the order by which the results are returned. They are also crucial when using the limit and skip parameters. In the order parameter of the basic query, a JSON string is expected to be placed with the following format:

[
    { "{NAME_OF_KEY}": "{1 (Ascending) or -1 (Descending)}" }
]

For example:

curl -X GET \
-G \
-H 'X-Warp-API-Key: 12345678abcdefg' \
--data-urlencoded 'sort=[{"type":1},{"age":-1}]' \
http://localhost:3000/api/1/classes/alien

User API

User accounts are often an essential part of an application. In Warp, these are represented by User Objects. Unlike regular Objects, User Objects have a special endpoint to manage operations applied to them:

/users

Thus, all the endpoints for the User object are the same as the endpoints for regular Objects, except for a few minor adjustments:

Create: POST /users
Update: PUT /users/{ID}
Delete: DELETE /users/{ID}
Fetch: GET /users/{ID}
Query: GET /users

Also, aside from these endpoints, the User Object has additional operations that can help in user management and authentication. These include logins, registration and session management endpoints.

Logging In

To log in to an existing user account, execute a POST request to:

/login

with a JSON Object that contains the specified user's username and password:

{ "username": "{USERNAME}", "password": "{PASSWORD}" }

Also, if you would like to track where the user logged in from, you can use the following header:

X-Warp-Origin: {ORIGIN}

For example:

curl -X POST \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'X-Warp-Origin: android' \
-H 'Content-Type: application/json' \
--data '{"username": "sarajanesmith", "password": "k9_and_luke"}' \
http://localhost:3000/api/1/login

You will receive a JSON response that contains the user and the session token for the successful login, similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "user": {
            "type": "Pointer",
            "id": 5
        },
        "origin": "android",
        "session_token": "981Tu3R831dHdh81s",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T22:11:09Z"
    }
}

Once received, it is important to securely store the session token and use it in succeeding queries for as long as the user is logged in:

-H 'X-Warp-Session-Key: 981Tu3R831dHdh81s'

Validating Users/Fetching Current User

To validate if a user session token is valid or to fetch the current user associated with a session token, execute a GET request to:

/users/me

with the session token included in the header:

X-Warp-Session-Key: 981Tu3R831dHdh81s

For example:

curl -X GET \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'X-Warp-Session-Token: 981Tu3R831dHdh81s' \
http://localhost:3000/api/1/users/me

The expected response would be similar to the following, if the session token is valid:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 5,
        "username": "sarajanesmith",
        "email": "sarajanesmith@tardis.com",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T22:11:09Z"
    }
}

Otherwise, it will return a Warp Error in the JSON response. For more info, please see the corresponding section regarding Warp Errors.

Signing Up

To register a new user, execute a POST request to:

/users

with a JSON Object that contains the desired keys of your new Object, including username, password and email:

{
    "username": "{USERNAME}",
    "password": "{PASSWORD}",
    "email": "{EMAIL}",
    "{KEY1}": "{VALUE1}", 
    "{KEY2}": "{VALUE2}"
}

For example:

curl -X POST \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'Content-Type: application/json' \
--data '{"username": "marthajones", "password": "doctorjones", "email": "martha@unit.co.uk"}' \
http://localhost:3000/api/1/users

The expected response would be similar to the following:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 9,
        "username": "marthajones",
        "email": "martha@unit.co.uk",
        "created_at": "2016-05-12T22:11:09Z",
        "updated_at": "2016-05-12T22:11:09Z"
    }
}

After creating the user, it is often good practice to chain another request to log in to the newly created user account automatically.

Logging Out

To log out of an existing user session, execute a GET request to:

/logout

with the session token included in the header:

X-Warp-Session-Token: 981Tu3R831dHdh81s

For example:

curl -X GET \
-H 'X-Warp-API-Key: 12345678abcdefg' \
-H 'X-Warp-Session-Token: 981Tu3R831dHdh81s` \
http://localhost:3000/api/1/logout

The expected response would be similar to the following, if the session token is valid:

{
    "status": 200,
    "message": "Success",
    "result": {
        "id": 9,
        "updated_at": "2016-05-12T22:11:09Z",
        "deleted_at": "2016-05-12T22:11:09Z"
    }
}

References

WarpServer.Model.Validation

FixedString(int: min, int: max) - checks whether a given string value has at least min characters and has, at most, max characters
Password(int: min, int: max) - same as FixedString but automatically appends the Password parser to the model, if added
Email - validates if a given string has the right email format
Integer - validates if a given value is an integer
PositiveInteger - validates if a given value is a counting number
Float - validates if a given value is a float value
Pointer - validates if a given value is a pointer; automatically appends the Pointer parser and Pointer formatter, if added

WarpServer.Model.Parser

NoSpaces - removes spaces from the entire string
Password - hashes a given string using bcrypt
Integer - parses a given value to an integer
Float - parses a given value to a float value
Date - parses a given string as a database-friendly datetime value
Pointer - parses a given pointer as a database-friendly value

WarpServer.Model.Formatter

Date - formats a retrieved value as an ISO 8061 date string (UTC)
Pointer - formats a retrieved value as a pointer

WarpServer.Model.PreSave

Session - automatically generates a random session_token for a session object and sets the deleted_at key relative to the set expiry date (default: 30 days)

WarpServer.Error Codes

Missing Configuration: 300 - a parameter is missing or a process has been omitted
Internal Sever Error: 100 - an unexpected error occurred internally
Query Error: 101 - an error occurred when querying the database
Invalid Credentials: 102 - credentials for a user operation are missing or are invalid
Invalid Session Token: 103 - session token is not set or is invalid
Invalid Object Key: 104 - an object could not be saved because a key failed validations
Invalid Pointer: 105 - a given pointer is invalid
Forbidden Operation: 106 - a user is not authorized to perform a requested operation
Username Taken: 107 - the provided username is already taken
Email Taken: 108 - the provided email is already taken
Invalid API Key: 109 - an API Key is not set or the given key is invalid
Model Not Found: 110 - the requested model/class does not exist