IoC Context Modules
Dynamically loadable IoC context modules conforming to @proc7ts/context-values API
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Context module can be used to provide multiple assets for IoC context at once. Unloading the module revokes all assets provided by it.
Usage example:
import { CxModule } from '@proc7ts/context-modules';
// Construct new module.
const myModule = new CxModule('my module', {
setup(setup) {
// Provide assets for `Foo` entry.
setup.provide(cxConstAsset(Foo, 'foo'));
},
});
// Add the module to context.
const myModuleSupply = cxBuilder.provide(myModule);
// Start using the module.
// The first usage of the module loads it.
const myModuleUse = await context.get(myModule).use();
// Await for the module to load.
await myModuleUse.whenReady;
// Access the value provided by module.
console.log(context.get(Foo)); // 'foo'
// Stop using the module.
// Once tha last usage stopped, the module is unloaded.
myModuleUse.supply.off();
// Revoke the module.
myModuleSupply.off();
Context module’s constructor accepts a human-readable module name, and options object.
The following options supported:
-
needs
- A module or modules the constructed one requires.The listed modules will be loaded prior to loading the constructed one.
-
has
- A module or modules the constructed one provides.When specified, the constructed module will be loaded instead of the listed ones.
-
setup()
- A method that sets up constructed module.May be synchronous or asynchronous.
Accepts a
CxModule.Setup
instance with the following properties:-
get()
- For accessing context values.Inherited from
ContextValues
interface. -
provide()
- For providing context entry assets.The same as in
CxBuilder
.All assets provided by this method will be revoked once the module unloaded.
-
initBy()
- For registering module initializers.
-
To use a module:
- Create its implementation.
- Provide it by
CxBuilder.provide(module)
call. - Obtain its handle from context by calling
CxValues.get(module)
. - Start using it by calling the
.use()
method of obtained module handle. - Wait for the module to load and become ready to use:
await use.whenReady
. -
When no longer needed, cut off the module use supply:
use.supply.off()
.The module will be unloaded once no longer uses remain.
Note that the module can be in use indirectly when required by another one.