Subscribing to Topics
Clients such as the YOUnite UI require real time updates of MDM events.
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This document provides client application developers the background needed to subscribe to YOUnite MDM notification topics and event types so they can receive real-time updates to MDM events. A topic is created for each MDM zone and for each MDM zone there are various notification types.
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Note: Currently we are using simple username/password authentication between the YOUnite UI and AMQ. All interaction between zones and clients that are tied to zones (e.g. YOUnite UI) should interact with AMQ with OAuth tokens or even better SSO→OAuth. See YOUMDM-103.
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Subscribing to Topics
MDM uses the Apache ActiveMQ messaging system which leverages the STOMP text-based messaging protocol. STOMP allows clients to be written easily. A STOMP protocol implementation in node.js can be found here.
Adding STOMP
Add the following libraries in your local workspace:
- amq_jquery_adapter.js
- amq.js
- stomp.js
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Note: Hari is working on inserted the STOMP libraries into the project . There may be some changes to the following using npm to install the libraries.
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Injecting STOMP Libraries
Directly add to the library section of your source code e.g. (use the appropriate path to your libraries):
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{src: `${this.ASSETS_SRC}/vendor-libs/js/amq_jquery_adapter.js`, inject: true, vendor: true},
{src: `${this.ASSETS_SRC}/vendor-libs/js/amq.js`, inject: true, vendor: true},
{src: `${this.ASSETS_SRC}/vendor-libs/js/stomp.js`, inject: true, vendor: true}, |
Subscribing to a Topic
Setup your credentials in your configuration (e.g. config.ts)
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//
// Define these in a config file e.g. config.ts
//
ACTIVEMQ_CLIENT: process.env.ACTIVEMQ_CLIENT ? process.env.ACTIVEMQ_CLIENT : 'ws://docker.local:61614',
ACTIVEMQ_USER_NAME: process.env.ACTIVEMQ_USER_NAME ? process.env.ACTIVEMQ_USER_NAME : 'admin',
ACTIVEMQ_PASSWORD: process.env.ACTIVEMQ_PASSWORD ? process.env.ACTIVEMQ_PASSWORD : 'admin', |
Setup your handler:
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subscribeNotification() {
this.loggedInZoneUuid = localStorage.getItem('zoneUuid');
this.client = Stomp.client(Config.ACTIVEMQ_CLIENT);
let topicUrl = '/topic/' + this.loggedInZoneUuid;
let connectHeaders = {
login: Config.ACTIVEMQ_USER_NAME,
passcode: Config.ACTIVEMQ_PASSWORD,
'client-id': this.loggedInZoneUuid
};
let componentRef = this;
let callback = function (message) {
// called when the client receives a STOMP message from the server
componentRef.toastr.info(message.body);
componentRef.incrementUnreadNotificationCount();
};
let subscribeHeaders = {'activemq.subscriptionName': this.loggedInZoneUuid};
this.client.connect(connectHeaders, function () {
componentRef.client.subscribe(topicUrl, callback, subscribeHeaders);
}
); |
Disconnect from the handler on logout, this should be in the same file as the above handler:
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this.client.disconnect();
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Notification Event Types
The following is list of event types that a subscriber can be notified of on a per zone (topic) basis. Each time an event is triggered it creates publishes a new topicnotification of a given event type .
Event | Event Type | Default Scope | Additional Payload |
---|---|---|---|
A zone is created | ZONE_POST | ALL | none |
A zone is updated | ZONE_PUT | ALL | none |
A zone is deleted | ZONE_DELETE | ALL | none |
A zone's thumbnail image is updated (TBD) | ZONE_THUMBNAIL_PUT | ALL | TBD |
A data domain is created or a new version of of the data domain has been created | DOMAIN_POST | ALL | TBD |
A data domain has been created | DOMAIN_PUT | ALL | TBD |
A data domain has been deleted | DOMAIN_DELETE | ||
?? | DOMAIN_NAME_POST | ||
A data domain has been updated | DOMAIN_NAME_PUT | ||
? | DOMAIN_DATA_POST | ||
? | DOMAIN_DATA_DELETEALL | TBD | |
An MDR has been created for a given data domain (TBD) | DOMAIN_NAME_DATA_POST | ALL | TBD |
An MDR has been updated in a given data domain . (TBD) | DOMAIN_NAME_DATA_PUT | ALL | TBD |
An MDR has been deleted in a give data domain . (TBD) | DOMAIN_NAME_DATA_DELETE |
Payload
The payload for an event includes:
Key | Description | |||||||
---|---|---|---|---|---|---|---|---|
Event Type (see above) | Originating zone UUID | Originating zone name | Status | Description | Message | Date Created | Key/Value map with additional information (NOTE: that should be documented for each event type)ALL | TBD |
Notification Event Response Body
The notification's JMS header includes the following:
key | value |
---|---|
description | A full description of the event - i.e. a full concatenation of the information described below for easy displaying. |
changeVersion | The resources change version. |
createdDate | The date the resource was created. |
Name | The resource name |
message-id | The JMS message ID. |
dateCreated | Unix timestamp of when the event notification was sent |
uuid | Zone uuid of target resource |
eventType | One of the above described "Notification Event Types" |
originatorName | The name of the zone that generated the event. |
originatorUuid | The UUID of the zone that generated the event. |
timestamp | The time the notification was created. |
optional | Other key/values that are appropriate for the notification type |
Requesting Notification Log
A client can make a request to get the log history for all notifications sent to their zone. The user provides their zone and a from and to date.