web3-provider-engine/dist/es5/subproviders/subprovider.js

A JavaScript library for composing Ethereum provider objects using middleware modules

"use strict";

var createPayload = require('../util/create-payload.js');
module.exports = SubProvider;

// this is the base class for a subprovider -- mostly helpers

function SubProvider() {}
SubProvider.prototype.setEngine = function (engine) {
  var self = this;
  if (self.engine) return;
  self.engine = engine;
  engine.on('block', function (block) {
    self.currentBlock = block;
  });
  engine.on('start', function () {
    self.start();
  });
  engine.on('stop', function () {
    self.stop();
  });
};
SubProvider.prototype.handleRequest = function (payload, next, end) {
  throw new Error('Subproviders should override `handleRequest`.');
};
SubProvider.prototype.emitPayload = function (payload, cb) {
  var self = this;
  self.engine.sendAsync(createPayload(payload), cb);
};

// dummies for overriding

SubProvider.prototype.stop = function () {};
SubProvider.prototype.start = function () {};