built.io/lib/extension.js

SDK for Built.io Backend

var R 				      			= require('ramda');
var utility 		      		= require('./utilities/utility');
var instanceMethodBuilder = require('./utilities/instanceMethodBuilder')();

/*
	Constants
*/
var extensionPath      = '/functions'; 
var allowedHttpMethods = ["GET", "POST", "PUT", "DELETE"]
/**
* @class Extension
* @classdesc   App.Extension allows you to add your own business logic to Built.io Backend. The business logic is written in JavaScript, and executed on the cloud.
* @instance
* @description Use this constructor to get an instance of Extension
* @param extension_key {String} The extension key of the extension application
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* 
* var extion = Built.App('blt5d4sample2633b').Extension('blt_extKey'); // blt_extKey is a extension key.
* @return {Extension}
*/
var extensionCons = module.exports = R.curry(function(app, extension_key) {
	if(!extension_key){
		extension_key = app.getExtensionKey()
	}

	var returnObj = {
		extension_key : extension_key,
		app           : app,
		toJSON        : function() {
			return extension_key
		}
	}
	installPluginsOnInst(returnObj)
	return instanceMethodBuilder.build(module.exports, returnObj)
})

/*
	pluginsHelper is global variable declared in built.js
*/
function installPluginsOnInst(ext){
	pluginsHelper.plugins.map(function(plugin){
		if(plugin.realtime && plugin.realtime.onExtensionsInstance){
			plugin.realtime.onExtensionsInstance(ext);
		}
	});
}

/**
Use the function to execute a function call deployed on Built.io Backend Extension.
* @function executeFunction
* @param method {String} The HTTP method of the function that needs to be executed (GET, POST, PUT, DELETE)
* @param fnUrl {String} The url of the function that needs to be executed
* @param reqBody {object} The request body that needs to be sent with the request (Optional)
* @param reqHeaders {object} Headers that need to be sent along with the request (Optional)
* @instance
* @memberof Extension
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var app = Built.App('blt5d4sample2633b')
* app.Extension()
* .executeFunction('GET', '/submit', body, headers)
* .then(function(result){
*    // do somethings
* });
* @return {Promise<Variable>}
*/
var execute = module.exports.executeFunction = R.curry(function(method, fnUrl, reqBody, reqHeaders, extension){
	if(!R.contains(method, allowedHttpMethods))
		throw new Error("invalid http method") 

	var app = extension.app
	method  = method || "POST"
	return makeFunctionCall(app.options.adaptor, method, getURL(fnUrl, extension.getExtensionKey(),app), getCombinedHeaders(extension, reqHeaders), reqBody, null);
});
instanceMethodBuilder.define('executeFunction', 5, [{}, {}]);

/**
Use the function to execute a get function call deployed on Built.io Backend Extension.
* @function get
* @param fnUrl {String} The url of the function that needs to be executed
* @param reqBody {object} The request body that needs to be sent with the request (Optional)
* @param reqHeaders {object} Headers that need to be sent along with the request (Optional)
* @instance
* @memberof Extension
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var app = Built.App('blt5d4sample2633b')
* app.Extension()
* .get('/getUser', body, headers)
* .then(function(result){
*    // do somethings
* });
* @return {Promise<Variable>}
*/
module.exports.get = execute('GET')
instanceMethodBuilder.define('get', 4, [{}, {}]);

/**
Use the function to execute a post function call deployed on Built.io Backend Extension.
* @function post
* @param fnUrl {String} The url of the function that needs to be executed
* @param reqBody {object} The request body that needs to be sent with the request (Optional)
* @param reqHeaders {object} Headers that need to be sent along with the request (Optional)
* @instance
* @memberof Extension
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var app = Built.App('blt5d4sample2633b')
* app.Extension()
* .post('/submit', body, headers)
* .then(function(result){
*    // do somethings
* });
* @return {Promise<Variable>}
*/
module.exports.post = execute('POST')
instanceMethodBuilder.define('post', 4, [{}, {}]);

/**
Use the function to execute a put function call deployed on Built.io Backend Extension.
* @function put
* @param fnUrl {String} The url of the function that needs to be executed
* @param reqBody {object} The request body that needs to be sent with the request (Optional)
* @param reqHeaders {object} Headers that need to be sent along with the request (Optional)
* @instance
* @memberof Extension
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var app = Built.App('blt5d4sample2633b')
* app.Extension()
* .put('/submit', body, headers)
* .then(function(result){
*    // do somethings
* });
* @return {Promise<Variable>}
*/
module.exports.put = execute('PUT')
instanceMethodBuilder.define('put', 4, [{}, {}]);

/**
Use the function to execute a delete function call deployed on Built.io Backend Extension.
* @function delete
* @param fnUrl {String} The url of the function that needs to be executed
* @param reqBody {object} The request body that needs to be sent with the request (Optional)
* @param reqHeaders {object} Headers that need to be sent along with the request (Optional)
* @instance
* @memberof Extension
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var app = Built.App('blt5d4sample2633b')
* app.Extension()
* .delete('/submit', body, headers)
* .then(function(result){
*    // do somethings
* });
* @return {Promise<Variable>}
*/
module.exports.delete = execute('DELETE')
instanceMethodBuilder.define('delete', 4, [{}, {}]);

/**
* Sets the extension key for an extension
* @memberof Extension
* @function setExtensionKey
* @param {String} extensionKey The Extension key
* @instance
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var extension = Built.App('blt5d4sample2633b').Extension().setExtensionKey('bltdb28fsaMplEf1b8');
* @return {Extension}
*/
module.exports.setExtensionKey = R.curry(function(extension_key, extension){
	return extensionCons(extension.app, extension_key)
})
instanceMethodBuilder.define('setExtensionKey', 2);

/**
* Gets the extension key for an extension
* @memberof Extension
* @function getExtensionKey
* @instance
* @example
* // 'blt5d4sample2633b' is a dummy Application API key
* var extension = Built.App('blt5d4sample2633b').Extension().setExtensionKey('bltdb28fsaMplEf1b8');
* console.log(extension.getExtensionKey());
* @return {String}
*/
module.exports.getExtensionKey = R.curry(function(extension){
	return extension.extension_key
})
instanceMethodBuilder.define('getExtensionKey', 1);

/**
* Determines whether extension_key is assigned to this Extension
* @function isNew
* @instance
* @memberof Extension 
* @example
* //'blt5d4sample2633b' is a dummy Application API key
* // 'local_extension' is a dummy extension_key
* var extApp  = Built.App('blt5d4sample2633b').Extension('local_extension')
* var boolean = extApp.isNew();
* @return {Boolean}
*/
module.exports.isNew = function(extension){
  return !! extension.getExtensionKey()
}
instanceMethodBuilder.define('isNew',1);

function makeFunctionCall(adaptor, method, path, headers, entity, params) {
	if(method == "GET") {
		params = entity
		entity = null
	}
	var requestObject = utility.getAdaptorObj(method, path, headers, entity, params);

  return adaptor.makeCall(requestObject).then(function(response) {
  	return response.entity
  });
}

function getURL (fnUrl, extension_key, app) {
	return app.getURL() + "/extensions/" + extension_key + extensionPath + fnUrl;
}

function getCombinedHeaders(extension, reqHeaders){
	reqHeaders = reqHeaders || {};
	reqHeaders = R.mixin({
		extension_key: extension.extension_key
	}, reqHeaders)

	var newHeaders = R.mixin(extension.app.getHeaders(),reqHeaders);
	return newHeaders;
}