Package Exports
- tapable
- tapable/lib/AsyncParallelHook
- tapable/lib/AsyncSeriesBailHook
- tapable/lib/AsyncSeriesHook
- tapable/lib/Hook
- tapable/lib/HookCodeFactory
- tapable/lib/HookMap
- tapable/lib/SyncBailHook
- tapable/lib/SyncHook
- tapable/lib/Tapable
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (tapable) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
Tapable
The tapable packages exposes many Hook classes, which can be used to create hooks for plugins.
const {
SyncHook,
SyncBailHook,
SyncWaterfallHook,
SyncLoopHook,
AsyncParallelHook,
AsyncParallelBailHook,
AsyncSeriesHook,
AsyncSeriesBailHook,
AsyncSeriesWaterfallHook
} = require("tapable");
Usage
All Hook constructors take one optional argument, which is a list of argument names as strings.
const hook = new SyncHook(["arg1", "arg2", "arg3"]);
The best practice is to expose all hooks of a class in a hooks
property:
class Car {
constructor() {
this.hooks = {
accelerate: new SyncHook(["newSpeed"]),
break: new SyncHook(),
calculateRoutes: new AsyncParallelHook(["source", "target", "routesList"])
};
}
/* ... */
}
Other people can now use these hooks:
const myCar = new Car();
// Use the tap method to add a consument
myCar.hooks.break.tap("WarningLampPlugin", () => warningLamp.on());
It's required to pass a name to identify the plugin/reason.
You may receive arguments:
myCar.hooks.accelerate.tap("LoggerPlugin", newSpeed => console.log(`Accelerating to ${newSpeed}`));
For sync hooks tap
is the only valid method to add a plugin. Async hooks also support async plugins:
myCar.hooks.calculateRoutes.tapPromise("GoogleMapsPlugin", (source, target, routesList) => {
// return a promise
return google.maps.findRoute(source, target).then(route => {
routesList.add(route);
});
});
myCar.hooks.calculateRoutes.tapAsync("BingMapsPlugin", (source, target, routesList, callback) => {
bing.findRoute(source, target, (err, route) => {
if(err) return callback(err);
routesList.add(route);
// call the callback
callback();
});
});
// You can still use sync plugins
myCar.hooks.calculateRoutes.tap("CachedRoutesPlugin", (source, target, routesList) => {
const cachedRoute = cache.get(source, target);
if(cachedRoute)
routesList.add(cachedRoute);
})
The class declaring these hooks need to call them:
class Car {
/* ... */
setSpeed(newSpeed) {
this.hooks.accelerate.call(newSpeed);
}
useNavigationSystemPromise(source, target) {
const routesList = new List();
return this.hooks.calculateRoutes.promise(source, target, routesList).then(() => {
return routesList.getRoutes();
});
}
useNavigationSystemAsync(source, target, callback) {
const routesList = new List();
this.hooks.calculateRoutes.callAsync(source, target, routesList, err => {
if(err) return callback(err);
callback(null, routesList.getRoutes());
});
}
}
The Hook will compile a method with the most efficient way of running your plugins. It generates code depending on:
- The number of registered plugins (none, one, many)
- The kind of registered plugins (sync, async, promise)
- The used call method (sync, async, promise)
- The number of arguments
- Whether interception is used
This ensures fastest possible execution.
Interception
All Hooks offer an additional interception API:
myCar.hooks.calculateRoutes.intercept({
call: (source, target, routesList) => {
console.log("Starting to calculate routes");
},
tap: (tapInfo) => {
// tapInfo = { type: "promise", name: "GoogleMapsPlugin", fn: ... }
console.log(`${tapInfo.name} is doing it's job`);
return tapInfo; // may return a new tapInfo object
}
})
call: (...args) => void
Adding call
to your interceptor will trigger when hooks are triggered. You have access to the hooks arguments.
tap: (tap: Tap) => void
Adding tap
to your interceptor will trigger when a plugin taps into a hook. Provided is the Tap
object. Tap
object can't be changed.
loop: (...args) => void
Adding loop
to your interceptor will trigger for each loop of a looping hook.
register: (tap: Tap) => Tap | undefined
Adding register
to your interceptor will trigger for each added Tap
and allows to modify it.
HookMap
A HookMap is a helper class for a Map with Hooks
const keyedHook = new HookMap(key => new SyncHook(["arg"]))
keyedHook.tap("some-key", "MyPlugin", (arg) => { /* ... */ });
keyedHook.tapAsync("some-key", "MyPlugin", (arg, callback) => { /* ... */ });
keyedHook.tapPromise("some-key", "MyPlugin", (arg) => { /* ... */ });
const hook = keyedHook.get("some-key");
if(hook !== undefined) {
hook.callAsync("arg", err => { /* ... */ });
}
Hook/HookMap interface
Public:
interface Hook {
tap: (name: string | Tap, fn: (context?, ...args) => Result) => void,
tapAsync: (name: string | Tap, fn: (context?, ...args, callback: (err, result: Result) => void) => void) => void,
tapPromise: (name: string | Tap, fn: (context?, ...args) => Promise<Result>) => void,
intercept: (interceptor: HookInterceptor) => void
}
interface HookInterceptor {
call: (context?, ...args) => void,
loop: (context?, ...args) => void,
tap: (context?, tap: Tap) => void,
register: (tap: Tap) => Tap,
context: boolean
}
interface HookMap {
for: (key: any) => Hook,
tap: (key: any, name: string | Tap, fn: (context?, ...args) => Result) => void,
tapAsync: (key: any, name: string | Tap, fn: (context?, ...args, callback: (err, result: Result) => void) => void) => void,
tapPromise: (key: any, name: string | Tap, fn: (context?, ...args) => Promise<Result>) => void,
intercept: (interceptor: HookMapInterceptor) => void
}
interface HookMapInterceptor {
factory: (key: any, hook: Hook) => Hook
}
interface Tap {
name: string,
type: string
fn: Function,
stage: number,
context: boolean
}
Protected (only for the class containing the hook):
interface Hook {
isUsed: () => boolean,
call: (...args) => Result,
promise: (...args) => Promise<Result>,
callAsync: (...args, callback: (err, result: Result) => void) => void,
}
interface HookMap {
get: (key: any) => Hook | undefined,
for: (key: any) => Hook
}
MultiHook
A helper Hook-like class to redirect taps to multiple other hooks:
const { MultiHook } = require("tapable");
this.hooks.allHooks = new MultiHook([this.hooks.hookA, this.hooks.hookB]);