Developing Business Networks
Developers use Hyperledger Composer to digitize business networks. The business network is accessed by multiple participants in the network, some of which may be responsible for the maintenance (hosting) of the network itself, referred to as maintainers of the network.
Typically each maintainer of the network will run several peer nodes (for crash fault tolerance) and Hyperledger Fabric replicates the distributed ledger across the set of peer nodes.
Model
Developers work with business analysts to define the domain data model for the business network. The data model is expressed using the Composer Modeling Language and defines the structure of the resources that will be stored on the ledger, or processed as transactions.
Once the domain model is in place, developers can capture smart contracts as executable transaction processor functions, written in JavaScript.
Access Control
In parallel developers or technical analysts can define the access control rules for the business network, to enforce which participants have access to the data on the ledger and under which conditions.
Deploy
Developers package the models, scripts and access control rules into a deployable Business Network Archive and use command line tools to deploy the archive to a runtime for testing.
Test
Like all business logic, it is important to create unit and system tests for business networks. Developers can use popular JavaScript testing frameworks such as Mocha and Chai to run unit tests (against the Node.js embedded runtime) or run system tests against a Hyperledger Fabric.
Integrate
Once the business network is tested and in place, front-end applications need to be created. Use the REST Server to automatically generate a REST API for a business network, and then a skeleton generate Angular application using the Yeoman code generator.
The REST Server can be configured to authenticate the participants in the business network, ensuring that credentials and permissions are enforced.