Lightstreamer SDK for Node Adapters 1.4.2
This package includes the resources needed to write Data Adapters and Metadata Adapters for Lightstreamer Server in a Node.js environment. The adapters will run in a separate process, communicating with the Server through the Adapter Remoting Infrastructure.
Install the package using npm
npm install lightstreamer-adapter
Download and install Lightstreamer
Go to the "adapters" folder of your Lightstreamer Server installation. Create a new folder to deploy the remote adapters in, let's call it "NodeAdapter".
Create an "adapters.xml" file inside the "NodeAdapter" folder and use the following contents (this is an example configuration, you can modify it to your liking by using the generic template,
DOCS-SDKs/adapter_remoting_infrastructure/doc/adapter_robust_conf_template/adapters.xml, as a reference):ROBUST_PROXY_FOR_REMOTE_ADAPTERlog-enabled800336000000ROBUST_PROXY_FOR_REMOTE_ADAPTERlog-enabled8001800236000000
Take note of the ports configured in the adapters.xml file as those are needed to write the remote part of the adapters.
Write the Adapters
Create a .js file, let's call it "adapters.js"
Get the net package and create the connections to Lightstreamer server. Note that the ports are the same used in the above file; LIGHTSTREAMER_SERVER_HOST is the host of the Lightstreamer server e.g.: "localhost".var net =reqRespStream = netnotifyStream = netmetadataStream = net;
Get the adapter classes and create the needed instancesvar MetadataProvider = MetadataProviderDataProvider = DataProviderdataProvider = reqRespStream notifyStreammetadataProvider = metadataStream;
Now you can register the events to respond to the adapters duties; see the documentation for the detailsdataProvider;dataProvider;metadataProvider;
Send updates for an item. Note that sending updates for items no one has subscribed to will result in an error, hence this calls must be bound to the "start/stop sending updates" comments int he subscribe/unsubscribe events:dataProvider;
From the command line call
Connect a Client
var lsClient = LIGHTSTREAMER_SERVER_HOST"PROXY_NODE";lsClient;
Note that the "PROXY_NODE" string is taken from the adapters.xml
This section is dedicated to developers who want to extend/modify the library itself, if you're simply looking to use it, ignore it.
We want to write code to use our package by requiring "lightstreamer-adapter" without having to specify the full path. On the other hand, during development, we do not want to install the package from the repo as we want to, in fact, test it before putting it on the repo for everyone else to enjoy. So:
- Go to the root of this project
- Go to the project where you need to use the development version of the package
npm link lightstreamer-adapter
NOTE: You can't globally link the package (using -g) to make it available everywhere
First install nodeunit
npm -g install nodeunit
The -g unit will install it on the system instead of installing it locally; you may remove it if you prefer a local installation
Go to the test folder and run the following commands
nodeunit dataprotocol.test.js nodeunit dataprovider.test.js nodeunit metadataprotocol.test.js nodeunit metadataprovider.test.js
- Get JSDoc 3
- Assuming you have the jsdoc folder in your path, go to this project folder and call
jsdoc --recurse --destination docs lib
The API documentation will be available in the docs folder.
- Adapter Remoting Infrastructure Network Protocol Specification
- Lightstreamer Chat Demo adapter for Node
Lightstreamer Compatibility Notes
Compatible with Adapter Remoting Infrastructure since 1.8