Whiteflag API JavaScript Modules

The Whiteflag API is written in JavaScript to run on Node.js. The source code of the Whiteflag API is organised in modules. Each module corresponds with a .js source code file. The source code files / modules are structured in the following directory tree:

Directory	Purpose
lib	Main modules
lib/operations	Operations modules
lib/protocol	Protocol modules
lib/blockchains	Blockchain modules
lib/datastores	Datastore modules
lib/common	Common modules

See also README.md for a general overview of the project, and CONTRIBUTING.md for a description of the repository structure and development guidelines for the source code.

Main modules

The main Whiteflag API module is whiteflag.js, which initialises all other main modules in lib/:

• config.js: the module that reads the api configuration from config/api.toml
• server.js: the module that opens the network connections and connects the routes and methods to the correct handlers in the endpoints modules
• blockchains.js: the module that implements the blockchain abstraction layer, and handles all requests to the configured blockchains
• datastores.js: the module that implements the datastores abstraction layer, and handles all requests to the configured databases

Endpoints modules

The operations modules in lib/operations contain the API endpoint operations functions that handle all requests and call the appropriate functions in the datastores, blockchain and protocol modules. The server.js binds the different endpoint handler functions to the correct endpoint routes and methods.

Protocol modules

All Whiteflag protocol features and logic is implemented in the protocol modules in lib/protocol. The protocol implementation is described seperately in protocol.md.

Blockchain modules

The blockchain modules in lib/blockchains implement the connections with the underlying blockchains. There is one module per supported blockchain. Functions in a specific blockchain module are called by the main module blockchains.js, which forms the blockchain abstraction layer.

The main module blockchains.js should check whether any request to one of the blockchain modules is correct, and whether the data returning from the blockchain through the callback function is correct.

A template for creating a new blockchain module to connect to a specific database is available with lib/blockchains/static/blockchain.template.js. Note that the function names in a blockchain module should reflect the function names in de main blockchains.js module.

The configuration of the blcockchains and the blockchain modules can be found in config/blockchains.toml. This configuration file has a section [[blockchains]] for each blockchain.

Datastore modules

The datastore modules in lib/datastores implement the connections with the unbderlying blockchains. There is one module per supported datastore. Functions in a specific datastore module are called by the main module datastores.js, which forms the datastore abstraction layer.

The main module datastores.js should check whether any request to one of the datastore modules is correct, and whether the data returning from the datastore through the callback function is correct.

A template for creating a new datastore module to connect to a specific database is available with lib/datastores/static/datastore.template.js. Note that the function names in a datastore module should reflect the function names in de main datastores.js module.

The configuration of the datastores and the datastore modules can be found in config/datastores.toml. This configuration file has a section [[databases]] for each datastore.

Common modules

Common modules in lib/common are used for function and class definitions shared by multiple modules across the project. Common modules may not require other project modules to function.