dbc-node-serviceprovider


Abstraction layer for the DBC webservices. Handles the communication between
the application- and the service layer providing optional transforms for
transforming the data received from the services before returning it to the
client.

Transforms

A transform is a form of event that takes a request and calls one or more services.
When service calls are resolved the Transform transforms the response into the desired format.
A transform is created with provider.registerTransform:Transform)

ServiceClients

A ServiceClient is an implementation of a client that handles communication with a service

API 1.0

$3

The provider needs to be initialized with a config file before usage.

``javascript
const Provider = require('dbc-node-serviceprovider');
const provider = Provider(config);
`

$3


Method for registering serviceclients. Serviceclients need a name that refers to a config namespace, and an init()
that provides the configurations and should return the client methods.

`javascript
import Recommendations from 'dbc-node-recommendations';

provider.registerServiceClient({
name: 'recommend',
init(config) {
return Recommendations(config.endpoint);
}
});
`

$3

Method for registering transform classes. Transforms need events, requestTransform, responseTransform

`javascript
provider.registerTransform({
event() {
return 'transformEvent';
},
requestTranform(request) {
// make a call to one or more services, using the callServiceClient method
return this.callServiceClient('moreinfo::method', request);
},
requestResponse(response) {
// do something with the reponse
return response;
}
});
`
#### Transform#callServiceClient:Promise
On a transform it is possible to make calls to registered clients in the following format

`javascript
const promise = this.callServiceClient('client', 'method', params);
`
callServiceClient returns a promise that should be returned from the requestTransform

$3

Triggers an event on the provider. If the event does not exists an error is thrown.
A transform with the corresponding event needs to be registered first.

the trigger method returns a Promise

`javascript
const recommendations = Provider.trigger('recommend', {like: ['123123123']});

recommendations
.then((result) => {
console.log(result);
})
.catch((error) => {
console.log(error)
});
`

$3


activates the bundled transforms and clients
`javascript
provider.boostrap();
`

$3

Setup socket api
`javascript
const app = express();
const server = require('http').Server(app);
const socket = require('socket.io').listen(server);

provider.setupSockets(socket);
`

Events

The provider inherits the Events API which is used to register events from the registered transforms

$3

add an event object
`javascript
Events.add('type', 'eventName', Function||Object);
`

$3

Retrieve a single event object
`javascript
const event = Events.get('type', 'eventName');
`

$3

Returns a map of events of a specified type

`javascript
const map = Events.getEventsOfType('type');
map.forEach((value, eventName) => console.log.bind(console));

`

Bundled clients

* MoreInfo.client.js
* OpenSearch.client.js
* OpenSuggest.client.js
* PopSuggest.client.js
* Recommendations.client.js

Bundled transforms

* CoverImage.transform.js
* ResultList.transform.js
* Work.transform.js
* OpenSuggest.transform.js
* PopSuggest.transform.js
* Recommendations.transform.js

API 2.0

$3

The provider needs to be initialized with a config file before usage.

`javascript
const Provider = require('dbc-node-serviceprovider');
const provider = Provider(someLoggerNotRequired);
`

$3


Method for registering serviceclients. Serviceclients need a name that refers to a config namespace, and an initialized client

`javascript
import Recommendations from 'dbc-node-recommendations';

const recommendations = Recommendations(config);

provider.registerServiceClient('recommend', recommendations);
`

$3

Method for registering transform classes. Transforms need events, requestTransform, responseTransform

`javascript
provider.registerTransform({
event() {
return 'transformEvent';
},
requestTranform(request) {
// make a call to one or more services, using the callServiceClient method
return this.clients.recommend.getRecommendations(request);
},
requestResponse(response) {
// do something with the reponse
return response;
}
});
`
#### Transform#callServiceClient:Promise (DEPRICATED)
Call serviceClients through the clients object on the transform

`javascript
const promise = this.clients.nameSpace.method(params);
`
Client calls always returns a promise that should be returned from the requestTransform

$3

Triggers an event on the provider. If the event does not exists an error is thrown.
A transform with the corresponding event needs to be registered first.

the trigger method returns a Promise

`javascript
const recommendations = Provider.trigger('recommend', {like: ['123123123']});

recommendations
.then((result) => {
console.log(result);
})
.catch((error) => {
console.log(error)
});
`

$3


Setup socket api
`javascript
const app = express();
const server = require('http').Server(app);
const socket = require('socket.io').listen(server);

provider.dispatcher(socket);
`

API 3.0

The new 3.0 api is almost identical to the 2.0 api, except it requires a socketcluster worker or something with an identical api.

$3

`javascript

module.exports.run = function (worker) {
const app = express();
const server = worker.httpServer;
const scServer = worker.getSCServer();

server.on('request', app);

...

provider.dispatcher(worker);
}

``