小编dev*_*ato的帖子

我正在使用jQuery.如何获取当前URL的路径并将其分配给变量？

示例网址:

http://localhost/menuname.de?foo=bar&number=0

@Component和@DirectiveAngular有什么区别？他们似乎都做同样的任务,并具有相同的属性.

有什么用例以及何时优先使用另一个？

我需要在没有ngFor的情况下使用异步管道.我需要检查与observable异步加载的对象的属性.

这就是我想要的,但不起作用:

 <ion-item *ngIf="user$.anonymouse | async">
     <ion-label>Login</ion-label>
 </ion-item>

//编辑:当我使用上面的代码时出现此错误

EXCEPTION:[!user $ .anonymouse |中的管道'AsyncPipe'的参数'true'无效 在SettingsPage @ 27:22中的异步]

有什么方法可以解决这个问题吗？

我知道我可以在Ctrl中将这个observable订阅商店值变成普通变量但是我不想这样做,因为性能等等.

我正在尝试使用 JavaScript 模块执行以下代码。我知道 NodeJS 默认是 CommonJS。我的代码在本地工作，但是当我想将其作为 lambda 中的模块运行时，我遇到了以下问题：

错误：

{
  "errorType": "ReferenceError",
  "errorMessage": "exports is not defined in ES module scope\nThis file is being treated as an ES module because it has a '.js' file extension and '/var/task/package.json' contains \"type\": \"module\". To treat it as a CommonJS script, rename it to use the '.cjs' file extension.",
  "trace": [
    "ReferenceError: exports is not defined in ES module scope",
    "This file is being treated as an ES module because it has a …

使用异步管道使用可观察数据服务直接在视图中更新数据,这证明难以测试(正常工作正常).

我希望能够更新视图,触发单击事件,然后测试模型是否已正确更新(由于单击),但在测试中,异步管道在其绑定的observable触发时不会呈现任何内容事件.所以我无法在测试中与DOM交互并测试交互的结果.

找不到任何人使用异步管道对组件进行单元测试的例子,所以我很茫然.任何反馈意见.

测试:

it('Updates the availability model correctly after UI interaction.', done => {

    this.instance.morning$
        .subscribe(data => {

            let checkboxes = this.fixture.nativeElement.querySelectorAll('ion-checkbox');
            TestUtils.trigger(checkboxes[0], 'click');

            let morningModel = this.instance.model.morning;
            expect(morningModel[0].v).toEqual(true);

            done();

        });         

});

模板:

<td *ngFor="let day of morning$ | async">
    <ion-checkbox [(ngModel)]="day.v"></ion-checkbox>
</td>

零件:

@Component({
    templateUrl: 'build/modules/availability/availability.view.html',
    selector: 'availability',
    providers: [AvailabilitySvc],
    directives: [Checkbox]
})
export class AvailabilityCom {

    @Input() userId: string;
    public morning$: any;

    constructor(private svc: AvailabilitySvc) {     
        this.morning$ = svc.morning$;
        this.setEvents();
    }

    ngOnInit(){
        this.getAvailability();
    }

    getAvailability(){
        return this.svc.get(this.userId); …

我正在努力一点一点地迁移一个大的angular.js应用程序(使用ui-router)到角度,我选择使用angular.js应用程序作为基础并一次迁移一个不同的路由,这样我曾经我完成了我立刻将所有东西切换到角度.

这些是我遵循的步骤:

在我的main.ts文件中启动angular.js应用程序:

export function bootstrapAngular(extra: StaticProvider[]): any {
  setAngularJSGlobal(angular);
  if (environment.production) {
    enableProdMode();
  }
  return platformBrowserDynamic(extra)
    .bootstrapModule(AppModule)
    .catch(err => console.log(err));
}

const downgraded = angular
  .module('downgraded', [downgradeModule(bootstrapAngular)])
  .directive('appRoot', downgradeComponent({ component: RootComponent, propagateDigest: false }))
  ;

angular.bootstrap(document, ['app', downgraded.name]);

在我的index.html里面

<app id="app"></app>

这很好用.

在我的主要angular.js组件中,我添加了降级后的主角度组件的标签:

<div class="app__view" id="appContent">
  <ui-view></ui-view>
  <app-root></app-root>
</div>

这就是我的主模块的配置方式

const COMPONENTS = [
  TestComponent,
  RootComponent,
];

@NgModule({
  declarations: COMPONENTS,
  imports: [
    BrowserModule,
    NxModule.forRoot(),
    RouterModule.forRoot(routes, {
      initialNavigation: 'enabled',
      useHash: true
    })
  ],
  providers: [
    { provide: APP_BASE_HREF, useValue: '/' …

我正在尝试创建一些环境变量，但是当我创建文件并运行服务器时，似乎未定义。我正在使用nodemon. 我已经重新启动了我的服务器，但没有运气。

更新

.env

MONGO_ATLAS_PW = "xxxx";
JWT_KEY = "secret_this_should_be_longer";

包.json

...
  "scripts": {
    ...
    "start:server": "nodemon ./server/server.js"
  }

应用程序.js

 require('dotenv').config();
 ...
 console.log(process.env.JWT_KEY); //undefined 

我正在尝试将Base64字符串转换为PDF并在浏览器中下载,并且生成的PDF不可读:

app.component.html - >

<div style="text-align:center">
  <form>
    <div class="form-row text-center">
      <button type="button" class="btn div-button" (click)="showPdf()">PDF</button>
    </div>
  </form>
</div>

app.component.ts - >

import {Component} from '@angular/core';

@Component({
  selector: 'app-root',
 templateUrl: './app.component.html',
 styleUrls: ['./app.component.css']
})
export class AppComponent {
  showPdf() {
    const pdfInBase64 = '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\n';
    const newBlob = new Blob([pdfInBase64], {type: 'application/pdf'});
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
      window.navigator.msSaveOrOpenBlob(newBlob); // For IE browser
    }
    const linkElement = document.createElement('a');
    const url = URL.createObjectURL(newBlob);
    linkElement.setAttribute('href', url);
    linkElement.setAttribute('download', 'sample.pdf');
    const clickEvent = new MouseEvent('click', {
      'view': …

我注意到，当我想编写一个粗箭头函数“ => ”时，我可以做_=>，()=> 或者(_)=>和我的代码功能相同（至少在我的用例中）

它们之间有实际区别吗？如果是，我应该使用哪一个？我()=>大部分时间都在使用，但是有一天有一天我看到某人的代码正在使用，_=>并且我认为它看起来很酷，所以我也开始使用它。

我看到了这篇中等文章https://medium.freecodecamp.org/when-and-why-you-should-use-es6-arrow-functions-and-when-you-shouldnt-3d851d7f0b26，作者声明您可以使用_=>或()=>但未指定是否有区别。

我对 NodeJS 很陌生。我正在尝试创建一个连接到我的 mongoDB Atlas 数据库的简单服务器，但是当我运行我的服务器时，我收到此错误：

UnhandledPromiseRejectionWarning：未处理的承诺拒绝。这个错误要么是因为在没有 catch 块的情况下抛出了异步函数，要么是因为拒绝了一个没有用 .catch() 处理过的承诺。(rejection id: 1) (node:8825) [DEP0018] DeprecationWarning：不推荐使用未处理的承诺拒绝。将来，未处理的承诺拒绝将使用非零退出代码终止 Node.js 进程。

根据我搜索的内容，这似乎是一个常见问题，我添加了 try/catch 但它仍然无法正常工作。

'use strict';
    //const AWS = require('aws-sdk');
    const express = require('express');
    const mongoose = require('mongoose');
    const uuidv4 = require('uuid/v4');

    //exports.handler = (event, context, callback) => {
    mongoose.connect(
      'mongodb+srv://xxxx:xxxx@cluster0-us8bq.mongodb.net/test?retryWrites=true',
      {
        useNewUrlParser: true
      }
    ),
      () => {
        try {
          //something
        } catch (error) {
          console.error(error);
        }
      };
    const connection = mongoose.connection;

    connection.once('open', () => {
      console.log(' Connection to DB was succesful'); …