Detailed explanation of the steps for calling child components from Angular parent components-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

Detailed explanation of the steps for calling child components from Angular parent components

php中世界最好的语言

Apr 20, 2018 pm 02:26 PM

angularcomponentsDetailed explanation

This time I will bring you a detailed explanation of the steps for calling a child component from an Angular parent component. What are the precautions for calling a child component from an Angular parent component? The following is a practical case, let's take a look.

Component is a special instruction that uses simpler configuration items to build a component-based application architecture. This article mainly introduces Angular components - parent components call child component methods. Friends who need it can Refer to the following

Understanding components

Component is a special instruction that uses simpler configuration items to build a component-based application architecture

This way he can simply write apps through similar web Component or angular2 styles.

web Component is a specification. It's about to become the standard.

Advantages of application components:

Simpler than ordinary command configuration
Provides better default settings and the best The practice
is more optimized for component-based application architecture.
The upgrade to angular2 is smoother.

Situation without construction:

For those instructions that need to perform operations in the compile or pre-link stage, the component cannot be used because it cannot Reach that stage.
If you want to define the priority, terminal, and multi-element of the instruction, it cannot be used.
Components can only be triggered through element tags, and others can only be triggered by commands.

viewChild decorator.

The template of the parent component and

Controller call the API of the child component.

1. Create a child component child1 which has only one greeting method for the parent component to call.

import { Component, OnInit } from '@angular/core';
@Component({
 selector: 'app-child1',
 templateUrl: './child1.component.html',
 styleUrls: ['./child1.component.css']
})
export class Child1Component implements OnInit {
 constructor() { }
 ngOnInit() {
 }
 greeting(name: string) {
 console.log("hello" + name);
 }
}

2. In the parent component, it is called using template local variables in the template and ts code in the controller.

Write 2

for the parent component and specify the template local variables

<app-child1> </app-child1>
<app-child1> </app-child1>

3 respectively, declare a viewChild decorator in the parent component controller The decorated variable gets the

reference of the child component.

Find the corresponding subcomponent through the name of the template variable child1 and assign it to the child1 variable. Once you get the reference, you can call the subcomponent method.

@ViewChild('child1')
child1:Child1Component; //父组件中获得子组件的引用
ngOnInit(){
 this.child1.greeting("Tom");
}

#4. Call the child component method in the parent component template.

Add a button to the parent component template and call the greeting method of the child component child2 when clicked.

<app-child1> </app-child1>
<app-child1> </app-child1>

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

Instructions for newbies to vue

##How to correctly use vue calculated properties

The above is the detailed content of Detailed explanation of the steps for calling child components from Angular parent components. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AM

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AM

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AM

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.

From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AM

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AM

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AM

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AM

I built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing

How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AM

This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base

See all articles