Dependency injection.
npm install --save di-ioc
module.exports = require('di-ioc').create()
// Start defining a `random` service:
.define('random', function () {
var pseudoRandomBytes = require('crypto').pseudoRandomBytes;
// The `random` service has one function:
return {
base64: function () {
return pseudoRandomBytes(20).toString('base64');
}
};
});module.exports = require('di-ioc').create()
// Greeting service which uses the random service: (arguments are detected)
.define(<
7568
/span>'greet', function (random) {
return function (name) {
console.log('Hello ' + name + '! Here is a random string: ' + random.base64());
};
});module.exports = require('di-ioc').create(require)
.use('./util')
.use('./app')
.init();
var randomService = module.exports.util.random;
// eQ/NZnl7qusVN9hB/3nCn3wFKfY=
console.log(randomService.base64());
// Hello World! Here is a random string: dfLGC20CpCJxAZSu+uFp57dlJl0=
module.exports.app.greet();- Export to a standard object which automatically initialises dependencies as needed. This is the object
.init()creates. - Enforce that dependency graph divides into layers. For example, nothing in the 'util' submodule can depend on services in the 'app' submodule, due to the order of definition.
- Nest components in to hierarchial modules and folders.
- Instantiate one sub-tree of the hierarchy for testing.
- Instantiate objects with injected dependencies for unit testing.
- Define transient objects, using
require('di-ioc').create().transient('serviceName', ...);.