Backend-js is a layer built above expressjs to enable behaviours framework for nodejs applications.


Keywords
backend, js, javascript, behaviour, design, map, queue, beam
License
MIT
Install
npm install backend-js@1.1.1

Documentation

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Backend-js is a layer built above expressjs to enable behaviours framework for nodejs applications.

Installation

npm install backend-js

Usage

backend

var backend = require('backend-js');
var App = backend.app(__dirname + '/behaviours', {
    path: '/api/v1',
    parser: 'json',
    port: 8383,
    origins: '*'
});
var App = app(path, options)
parameter type description
path string path of behaviours directory.
options object app configurations object.
options.path string prefix path appended to the beginning of routes.
options.parser string if json, text, raw or urlencoded is used, the body of the request will be parse accordingly also the body of the response will be serialized accordingly.
options.parserOptions object options for parser.
options.port number port of server.
options.origins string comma separated domains allowed to send ajax requests to this server or "*" to allow any.
options.static object options object to define static served files.
options.static.route string virtual path/route for static served files.
options.static.path string relative path of the directory of static served files.
return type description
App function function conventionally denotes the Express application.

model

var backend = require('backend-js');
var model = backend.model();
var User = model({
  name: 'User'
}, {
  username: String,
  password: String
});
var ModelEntity = model(options, attributes, plugins)
parameter type description
options string | object either model name for lazy loading or object for model configuration.
options.name string model name.
options.features object object contains special functionalities of the model. It is passed to data access layer.
options.query array array of QueryExpression repressing the query to be executed by default.
attributes object object describes the model schema. it contains key-value pairs where the key is a model attribute/field name and the value is the data type of this attribute/field. Data types are native javascript data types String, Number and Date. Data type could be javascript array of single object annotation [{}] or just an object annotation {} containing other key-value pairs expressing nested model schema.
plugins array array of mongoose plugins to define additional functionalities to the model.
return type description
ModelEntity function model constructor function prototyped as ModelEntity.

query

var QueryExpression = backend.QueryExpression;
var ComparisonOperators = {
    EQUAL: '=',
    NE: '$ne'
};
var LogicalOperators = {
    AND: '$and',
    OR: '$or',
    NOT: '$not'
};
backend.setComparisonOperators(ComparisonOperators);
backend.setLogicalOperators(LogicalOperators);
var query = [new QueryExpression({
    fieldName: 'username',
    comparisonOperator: ComparisonOperators.EQUAL,
    fieldValue: 'name'
}),new QueryExpression({    
    fieldName: 'password',
    comparisonOperator: ComparisonOperators.EQUAL,
    fieldValue: 'pass',
    logicalOperator: LogicalOperators.AND,
    contextualLevel: 0
})]
setComparisonOperators(operators)
setLogicalOperators(operators)
parameter type description
operators object object contains key-value pairs where the key is a unique id for an operator and the value is a corresponding database engine operator. It is passed to data access layer.
var expression = new QueryExpression(options)
parameter type description
options object object describes a condition in a where clause of a query.
options.fieldName string attribute/field name of the model to be part of the condition.
options.comparisonOperator string a value represents comparison operation to be manipulated by database engine.
options.fieldValue any the value to be compared to the attribute/field of the model.
options.logicalOperator string a value represents logical operation to be manipulated by database to combine multiple conditions.
options.contextualLevel number starts with 0 represents the depth of the logical operation in the conditions tree. It is used to indicate brackets.
return type description
expression object object represents a condition expression combined with other expressions to represent a query. It is adapted by data access layer..

entity

var ModelEntity = backend.ModelEntity;
var entity = new ModelEntity({});
var model = entity.getObjectConstructor();
var schema = entity.getObjectAttributes();
var features = entity.getObjectFeatures();
var query = entity.getObjectQuery();
var entity = new ModelEntity(features)
parameter type description
features object object contains special functionalities of the model. It is passed to data access layer.
return type description
entity object object contains all specifications and meta data of the model.
entity.getObjectConstructor function function returns the model constructor depending on the data access layer.
entity.getObjectAttributes function function returns the model schema key-value pairs.
entity.getObjectFeatures function function returns the model features.
entity.getObjectQuery function function returns the model query an array of QueryExpression to be executed by default.

behaviour (API / functional code unit)

var getUsers = behaviour({
  name: 'GetUsers',
  version: '1',
  path: '/users',
  method: 'GET'
}, function(init) {
  return function() {
    var self = init.apply(this, arguments).self();
    self.begin('Query', function(key, businessController, operation) {
        operation
          .entity(new User())
          .append(true)
          .apply();
      });
  };
});
var Behavior = behaviour(option, constructor);
parameter type description
options object api configuration (name, version, path, method, parameters, returns)
constructor function logic function works by registering on methods to do functions regardless its orders, like (database processor query, insert, delete or update), data mapping to map returns of data to specific format or server error handling

data access

you should define your own data access layer like following

var backend = require('backend-js');

var ModelController = function () {
    self.removeObjects = function (queryExprs, entity, callback) {
        // do remove
    };
    self.newObjects = function (objsAttributes, entity, callback) {
        // do add new
    };
    self.getObjects = function (queryExprs, entity, callback) {
        // do select
    };
    self.save = function (callback, oldSession) {
        // do select
    };
};

ModelController.defineEntity = function (name, attributes) {
    // define entity
    return entity;
};

ModelController.prototype.constructor = ModelController;

backend.setModelController(new ModelController());

Starter project

A sample project that you can learn from examples how to use Backend-JS.

https://github.com/QuaNode/BeamJS-Start