小编Mim*_*imo的帖子

我正在查看一些代码片段,我发现多个元素在一个节点列表上调用一个函数,并将forEach应用于一个空数组.

例如,我有类似的东西:

[].forEach.call( document.querySelectorAll('a'), function(el) {
   // whatever with the current node
});

但我无法理解它是如何工作的.任何人都可以解释我在forEach前面的空数组的行为以及它是如何call工作的？

我在我的主模板中定义了一个全局变量,我用它来存储来自后端的信息位,例如环境上下文路径.我无法在服务中移动该变量.

当我运行单元测试时,如何将该变量公开给Karma？

我的范围内有一个函数可以在用户单击按钮时检索我的服务状态,或者触发某个事件并自动调用此函数.

这是我的功能,在我使用的控制器中定义:

$scope.getStatus = function() {
  $http({method: 'GET', url: config.entrypoint + config.api + '/outbound/service/' + $scope.serviceId})
    .success(function(data) {
      $scope.errorMessage = '';
      $scope.serviceAllGood = data;
    })
    .error(function() {
      $scope.serviceAllGood = '';
      $scope.errorMessage = 'We are experiencing problems retrieving your service status.';
    });
  }

单元测试如下:

describe('SendServiceCtrl', function(){
    var scope, ctrl, $httpBackend, configuration;

    beforeEach(function () {
      module('papi', 'ngUpload');
    });

    beforeEach(inject(function(_$httpBackend_, $rootScope, $controller, config) {
      configuration = config;
      $httpBackend = _$httpBackend_;
      $httpBackend.expectGET(configuration.entrypoint + configuration.api + "/user/outboundstatus/").respond(200, {"meta":{"apiVersion":"0.1","code":200,"errors":null},"response":{"allowed":false}});
      scope = $rootScope.$new();
      ctrl = $controller('SendServiceCtrl', {$scope: …

我试图让Redux Form第一次工作,我收到以下错误:

删除了不变违反withRef.要访问包装的实例,请在连接的组件上使用ref.

我究竟做错了什么？一旦我写了(从示例中复制/粘贴)商店,就会抛出错误.

这是代码.

import React from "react";
import ReactDOM from "react-dom";
import { createStore, combineReducers } from 'redux'
import { reducer as formReducer } from 'redux-form'

const rootReducer = combineReducers({
  form: formReducer
})

const store = createStore(rootReducer);


function App() {
  return (
    <div className="App">
      <h1>Hello CodeSandbox</h1>
      <h2>Start editing to see some magic happen!</h2>
    </div>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

我还创建了一个代码沙箱来显示问题:https://codesandbox.io/s/07xzolv60

我想在Yeoman/Grunt项目中使用TypeScript.要编译TypeScript我使用一个名为grunt-ts的grunt插件,.ts文件的编译工作正常,但实时重新加载不起作用:当我运行时grunt server我正确得到这个:

Running "ts:dev" (ts) task
Compiling.
Success: 3.37s for 2 typescript files
Watching all Typescript files under : /home/mimo/webroot/tsyong/app/scripts

但是然后没有加载liveReload任务.这就是我如何配置关于grunt-ts的Gruntfile.js.

  grunt.initConfig({
    ...
    ts: {
      options: {                    // use to override the default options, http://gruntjs.com/configuring-tasks#options
        target: 'es3',            // es3 (default) / or es5
        module: 'commonjs',       // amd , commonjs (default)
        sourcemap: true,          // true  (default) | false
        declaration: false,       // true | false  (default)
        nolib: false,             // true | false (default)
        comments: false           // true | false (default) …

在检查一些代码时,我发现了这个新的声明:-webkit-padding-start但是我无法理解与现有padding-left属性有什么区别.我已经阅读了有关Mozilla开发人员的页面并创建了一个小提琴,但我仍然不确定.

我试图避免在工厂中向服务器发出多个ajax请求.我已经添加了一个小的缓存服务,但这还不足以满足我的目标:在服务器响应之前可以多次调用此工厂,从而导致向服务器生成多个请求.

为了避免这种情况,我添加了第二个promise对象,如果已经执行了AJAX请求并且对象尚未在缓存中,那么它应该等待第二个promise被解析,但看起来我错过了一些东西.

这是我的代码:

myApp.factory('User', ['Restangular', '$q',
  function (Restangular, $q) {
    var userCache, alreadyRun = false;
    return {
      getUser: function () {
        var deferred = $q.defer(), firstRun= $q.defer();

        if (!userCache && !alreadyRun) {
          alreadyRun = true;

          Restangular.all('user').getList().then(function (user) {
            console.log('getting user live ');
            userCache = user[0].email;
            firstRun.resolve(user[0].email);
          });
        } else if (!userCache && alreadyRun) {
          console.log('waiting for the first promise to be resolved ');
          firstRun.then(function(user) {
            console.log('resolving the promise');
            deferred.resolve(userCache);
          });

        } else {
          console.log('resolving the promise from the cache');
          deferred.resolve(userCache) …

我正在使用Restangular构建一个应用程序.我会在一个地方实现处理错误,如401,403,500等在响应拦截器中.

这就是我写的:

RestangularProvider.setResponseExtractor(function(response, operation, what, url) {
  switch(response.meta.code) {
    case 200:
      // Handle 200
    break;

    case 401:
      // Redirect to login
    break;

    /* ... */

    default:
    break;
  }
}

实际发生的是200正确看到但是这个方法根本没有被401命中.我从服务器端获得的JSON格式如下,以便成功响应:

{"meta":{"apiVersion":"0.1","code":200,"errors":null},"response":{"response":"value"}}

和

{"meta":{"apiVersion":"0.1","code":401,"errors":[{"code":401,"message":"Unauthorized"}]},"response":null}

为了错误.响应头也包含Status Code:401 Unauthorized.我究竟做错了什么？

我正在学习Haskell并遵循http://learnyouahaskell.com/starting-out上的指南.我正处于显示的位置:

ghci> let nouns = ["hobo","frog","pope"]  
ghci> let adjectives = ["lazy","grouchy","scheming"]  
ghci> [adjective ++ " " ++ noun | adjective <- adjectives, noun <- nouns]  
["lazy hobo","lazy frog","lazy pope","grouchy hobo","grouchy frog",  
"grouchy pope","scheming hobo","scheming frog","scheming pope"]   

我想要实现的,它是类似的,但结合两个字符串中包含的字母,因为字符串基本上是Haskell中的char列表,​​这是我尝试的:

 [x ++ ' ' ++ y | x <- "ab", y <- "cd"]

但编译器抱怨:

Prelude> [y ++ ' ' ++ y | x <- "abd", y <- "bcd"]

<interactive>:50:2:
    Couldn't match expected type ‘[a]’ with actual type ‘Char’
    Relevant bindings include …

我刚刚开始通过示例学习purescript ,但是我在第2章的末尾使用了grunt项目模板.我按照说明操作,但是当我运行grunt命令时,我收到此错误:

/Users/chad/playground/purescript/tests/tmp/node_modules/Control.Monad.Eff.Random/index.js:8
return Math.random();
            ^
TypeError: undefined is not a function
    at Object.random (/Users/chad/playground/purescript/tests/tmp/node_modules/Control.Monad.Eff.Random/index.js:8:17)
    at __do (/Users/chad/playground/purescript/tests/tmp/node_modules/Test.QuickCheck/index.js:177:52)
    at Object.__do (/Users/chad/playground/purescript/tests/tmp/node_modules/Main/index.js:19:201)
    at Object.<anonymous> (/Users/chad/playground/purescript/tests/tmp/index.js:1:79)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:501:10)
    at startup (node.js:129:16)
Warning: -> error 1 /Users/chad/playground/purescript/tests/tmp/index.js (125ms) Use --force to continue.

Aborted due to warnings.

我通过深入研究代码发现,模块Math被导入为/output/Control.Monad.Eff.Random/index.jsas

var Math = require("Math");

function random() {
    return Math.random();
}
;

如果我删除导入,让Math是原生的并且index.js简单地运行main …

我是一个Rails新手,因此我遵循入门指南,可在此处获取:http://edgeguides.rubyonrails.org/getting_started.html此处:http://guides.rubyonrails.org/getting_started.html但我可以没有达到5.6/5.7的要求.

这是我的控制器:

class PostsController < ApplicationController
    def new
    end

    def show
        @post = Post.find(params[:id])
    end

    def create
      @post = Post.new(post_params)

      @post.save
      redirect_to @post
    end

    private
    def post_params
        params.require(:post).permit(:title, :text)
    end

end

这是我的形式:

<%= form_for :post, url: posts_path do |f| %>
    <p>
        <%= f.label :title %><br>
        <%= f.text_field :title %>
    </p>

    <p>
        <%= f.label :text %> <br>
        <%= f.text_area :text %>
    </p>

    <p>
        <%= f.submit %>
    </p>
<% end %>

这是routes.rb

Blog::Application.routes.draw do …