node-nlp
Version:
Library for NLU (Natural Language Understanding) done in Node.js
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JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
/**
* A set of `Middleware` plugins.
*
* @remarks
* The set itself is middleware so you can easily package up a set of middleware that can be composed
* into an adapter with a single `adapter.use(mySet)` call or even into another middleware set using
* `set.use(mySet)`.
*
* ```JavaScript
* const { MiddlewareSet } = require('botbuilder');
*
* const set = new MiddlewareSet();
* set.use(async (context, next) => {
* console.log(`Leading Edge`);
* await next();
* console.log(`Trailing Edge`);
* });
* ```
*/
class MiddlewareSet {
/**
* Creates a new MiddlewareSet instance.
* @param middleware One or more middleware handlers(s) to register.
*/
constructor(...middleware) {
this.middleware = [];
MiddlewareSet.prototype.use.apply(this, middleware);
}
onTurn(context, next) {
return this.run(context, next);
}
/**
* Registers middleware handlers(s) with the set.
*
* @remarks
* This example adds a new piece of middleware to a set:
*
* ```JavaScript
* set.use(async (context, next) => {
* console.log(`Leading Edge`);
* await next();
* console.log(`Trailing Edge`);
* });
* ```
* @param middleware One or more middleware handlers(s) to register.
*/
use(...middleware) {
middleware.forEach((plugin) => {
if (typeof plugin === 'function') {
this.middleware.push(plugin);
}
else if (typeof plugin === 'object' && plugin.onTurn) {
this.middleware.push((context, next) => plugin.onTurn(context, next));
}
else {
throw new Error(`MiddlewareSet.use(): invalid plugin type being added.`);
}
});
return this;
}
/**
* Executes a set of middleware in series.
* @param context Context for the current turn of conversation with the user.
* @param next Function to invoke at the end of the middleware chain.
*/
run(context, next) {
const handlers = this.middleware.slice();
function runNext(i) {
try {
if (i < handlers.length) {
return Promise.resolve(handlers[i](context, () => runNext(i + 1)));
}
else {
return Promise.resolve(next());
}
}
catch (err) {
return Promise.reject(err);
}
}
return runNext(0);
}
}
exports.MiddlewareSet = MiddlewareSet;
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