NGSI source operator

The NGSI source operator is a WireCloud operator usable for adding NGSI subscription support to your dashboards in a simple way. Those subscriptions are a great feature provided by the Orion Context Broker.

Latest version of this operator is always provided in FIWARE Lab where you can make use of it on the Mashup portal. Remember to take a look into the example mashups provided in the OrionStarterKit offering.

Build

Be sure to have installed Node.js. For example, you can install it on Ubuntu and Debian running the following commands:

curl -sL https://deb.nodesource.com/setup | sudo bash -
sudo apt-get install nodejs
sudo apt-get install npm

Install other npm dependencies by running:

npm install

For build the widget you need download grunt:

sudo npm install -g grunt-cli

And now, you can use grunt:

grunt

If everything goes well, you will find a wgt file in the dist folder.

Settings and Usage

Settings

NGSI server URL: URL of the Orion Context Broker to use for retrieving entity information.
NGSI proxy URL: URL of the Orion Context Broker proxy to use for receiving notifications about changes.
Use the FIWARE credentials of the user: Use the FIWARE credentials of the user logged into WireCloud. Take into account this option cannot be enabled if you want to use this widget in a public workspace as anonoymous users doesn't have a valid FIWARE auth token. As an alternative, you can make use of the "Use the FIWARE credentials of the workspace owner" preference.
Use the FIWARE credentials of the dashboard owner: Use the FIWARE credentials of the owner of the workspace. This preference takes preference over "Use the FIWARE credentials of the user". This feature is available on WireCloud 0.7.0+ in a experimental basis, future versions of WireCloud can change the way to use it making this option not funcional and requiring you to upgrade this operator.
NGSI tenant/service: Tenant/service to use when connecting to the context broker. Must be a string of alphanumeric characters (lowercase) and the _ symbol. Maximum length is 50 characters. If empty, the default tenant will be used
NGSI scope: Scope/path to use when connecting to the context broker. Must be a string of alphanumeric characters (lowercase) and the _ symbol separated by / slashes. Maximum length is 50 characters. If empty, the default service path will be used: /
NGSI entity types: A comma separated list of entity types to use for filtering entities from the Orion Context broker. This field cannot be empty.
Id pattern: Id pattern for filtering entities. This preference can be empty, in that case, entities won't be filtered by id.
Monitored NGSI Attributes: Attributes to monitor for updates. Currently, the Orion Context Broker requires a list of attributes to monitor for changes, so this field cannot be empty.

NOTE If you are using a custom instance of the Orion Context Broker, take into account that by default Orion doesn't support sending notifications to https endpoints. In those cases you can make use of a NGSI available through http at (http://ngsiproxy.lab.fiware.org) instead of using the default one that uses https (https://ngsiproxy.lab.fiware.org). Anyway, it is very recommended to enable the https support (see this link for more info about this matter).

Wiring

Input Endpoints

This widget has no input endpoint

Output Endpoints

Provide entity: This operator sends an event thought this endpoint for each entity update retrieved from the context broker. In addition to this, this operator send an event for every entity available initially on the context broker.

In any case, event data follows the format used by the NGSI API of WireCloud for returning. E.g.
```
{
    "id": "van4",
    "type": "Van",
    "current_position": "43.47173, -3.7967205"
}
```

Copyright and License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Mognom / ngsi-source-operator