Merge pull request #1041 from ethereum/refactor/udapp_refactor_waterfall

src/universal-dapp.js

 /* global */
 'use strict'
 
+var async = require('async')
 var ethJSUtil = require('ethereumjs-util')
 var BN = ethJSUtil.BN
 var remixLib = require('remix-lib')
@@ -201,99 +202,66 @@ UniversalDApp.prototype.getInputs = function (funABI) {
   return txHelper.inputParametersDeclarationToString(funABI.inputs)
 }
 
-function execute (pipeline, env, callback) {
-  function next (err, env) {
-    if (err) return callback(err)
-    var step = pipeline.shift()
-    if (step) step(env, next)
-    else callback(null, env.result)
-  }
-  next(null, env)
-}
-
 UniversalDApp.prototype.runTx = function (args, cb) {
-  var self = this
-  var tx = { to: args.to, data: args.data.dataHex, useCall: args.useCall, from: args.from, value: args.value }
-  var payLoad = { funAbi: args.data.funAbi, funArgs: args.data.funArgs, contractBytecode: args.data.contractBytecode, contractName: args.data.contractName } // contains decoded parameters
-  var pipeline = [queryGasLimit]
-  if (!args.value) {
-    pipeline.push(queryValue)
-  }
-  if (!args.from) {
-    pipeline.push(queryAddress)
-  }
-  pipeline.push(runTransaction)
-  var env = { self, tx, payLoad }
-  execute(pipeline, env, cb)
-}
-
-function queryGasLimit (env, next) {
-  var { self, tx } = env
-  tx.gasLimit = 3000000
+  const self = this
+  async.waterfall([
+    function getGasLimit (next) {
       if (self.transactionContextAPI.getGasLimit) {
-    self.transactionContextAPI.getGasLimit(function (err, ret) {
-      if (err) return next(err)
-      tx.gasLimit = ret
-      next(null, env)
-    })
-  } else next(null, env)
-}
-
-function queryValue (env, next) {
-  var { self, tx } = env
-  tx.value = 0
-  if (tx.useCall) return next(null, env)
-  if (self.transactionContextAPI.getValue) {
-    self.transactionContextAPI.getValue(function (err, ret) {
-      if (err) return next(err)
-      tx.value = ret
-      next(null, env)
+        return self.transactionContextAPI.getGasLimit(next)
+      }
+      next(null, 3000000)
+    },
+    function queryValue (gasLimit, next) {
+      if (args.value) {
+        return next(null, args.value, gasLimit)
+      }
+      if (args.useCall || !self.transactionContextAPI.getValue) {
+        return next(null, 0, gasLimit)
+      }
+      self.transactionContextAPI.getValue(function (err, value) {
+        next(err, value, gasLimit)
       })
-  } else next(null, env)
-}
-
-function queryAddress (env, next) {
-  var { self, tx } = env
+    },
+    function getAccount (value, gasLimit, next) {
+      if (args.from) {
+        return next(null, args.from, value, gasLimit)
+      }
       if (self.transactionContextAPI.getAddress) {
-    self.transactionContextAPI.getAddress(function (err, ret) {
-      if (err) return next(err)
-      tx.from = ret
-      next(null, env)
+        return self.transactionContextAPI.getAddress(function (err, address) {
+          next(err, address, value, gasLimit)
         })
-  } else {
-    self.getAccounts(function (err, ret) {
+      }
+      self.getAccounts(function (err, accounts) {
+        let address = accounts[0]
+
         if (err) return next(err)
-      if (ret.length === 0) return next('No accounts available')
-      if (executionContext.isVM() && !self.accounts[ret[0]]) {
+        if (!address) return next('No accounts available')
+        if (executionContext.isVM() && !self.accounts[address]) {
           return next('Invalid account selected')
         }
-      tx.from = ret[0]
-      next(null, env)
+        next(null, address, value, gasLimit)
       })
-  }
-}
-
-function runTransaction (env, next) {
-  var { self, tx, payLoad } = env
+    },
+    function runTransaction (fromAddress, value, gasLimit, next) {
+      var tx = { to: args.to, data: args.data.dataHex, useCall: args.useCall, from: fromAddress, value: value, gasLimit: gasLimit }
+      var payLoad = { funAbi: args.data.funAbi, funArgs: args.data.funArgs, contractBytecode: args.data.contractBytecode, contractName: args.data.contractName }
       var timestamp = Date.now()
+
       self.event.trigger('initiatingTransaction', [timestamp, tx, payLoad])
       self.txRunner.rawRun(tx, function (error, result) {
-    if (!tx.useCall) {
-      self.event.trigger('transactionExecuted', [error, tx.from, tx.to, tx.data, false, result, timestamp, payLoad])
-    } else {
-      self.event.trigger('callExecuted', [error, tx.from, tx.to, tx.data, true, result, timestamp, payLoad])
-    }
-    if (error) {
-      if (typeof (error) !== 'string') {
+        let eventName = (tx.useCall ? 'callExecuted' : 'transactionExecuted')
+        self.event.trigger(eventName, [error, tx.from, tx.to, tx.data, tx.useCall, result, timestamp, payLoad])
+
+        if (error && (typeof (error) !== 'string')) {
           if (error.message) error = error.message
           else {
             try { error = 'error: ' + JSON.stringify(error) } catch (e) {}
           }
         }
-    }
-    env.result = result
-    next(error, env)
+        next(error, result)
       })
+    }
+  ], cb)
 }
 
 module.exports = UniversalDApp