The @ViewChild decorator allows us to inject into a component class references to elements used inside its template, that’s what we should use it for. Using @ViewChild we can easily inject components, directives or plain DOM elements.
Besides, How does ViewChild work in Angular?
ViewChildlink
Property decorator that configures a view query. The change detector looks for the first element or the directive matching the selector in the view DOM. If the view DOM changes, and a new child matches the selector, the property is updated.
Keeping this in mind, What is ViewChild and ViewChildren in Angular? The @ViewChild and @ViewChildren decorators in Angular provide access to child elements in the view DOM by setting up view queries. A view query is a requested reference to a child element within a component view which contains metadata of the element.
What is the difference between ViewChild () and ContentChild ()?
ViewChild is used to select an element from component’s template while ContentChild is used to select projected content.
What is the use of renderer in Angular?
The Renderer class is a built-in service that provides an abstraction for UI rendering manipulations. For example, you need to set the focus on an input element, so you may be tempted to do something like: This works fine.
How lazy loading works in Angular?
Lazy loading is a technique in Angular that allows you to load JavaScript components asynchronously when a specific route is activated. It improves the speed of the application load time by splitting the application into several bundles. When the user navigates through the app, the bundles are loaded as required.
What is ViewChild and ViewChildren?
Both ViewChild and ViewChildren are used to communicate between the components to access the data. @ViewChild and @ViewChildren are the types of decorators used to access the child component class and its different properties into the parent component. It’s similar to the inheritance.
Why do we need ViewChild and ViewChildren in Angular?
ViewChild and ViewChildren can be used to access the properties and methods of the child component. … We will look into the code to access the child component’s properties and methods from the parent component using @ViewChild .
What is ContentChild and ContentChildren?
The ContentChild & ContentChildren are decorators, which we use to Query and get the reference to the Projected Content in the DOM. Projected content is the content that this component receives from a parent component. The ContentChild & ContentChildren is very similar to the ViewChild & ViewChildren.
What is ContentChild?
ContentChildren is a parameter decorator that is used to fetch the QueryList of elements or directives from the content DOM. The QueryList is updated whenever the child element/component is added or removed.
What does ViewChild return?
The ViewChild or ViewChildren decorators are used to Query and get the reference of the DOM element in the Component. ViewChild returns the first matching element and ViewChildren returns all the matching elements as a QueryList of items. We can use these references to manipulate element properties in the component.
What is rendering in Angular?
Angular Universal is the process of server-side rendering (SSR) your application to HTML on the Server (ie: Node. … Typical Angular applications are Single-Page Applications (aka SPA’s) where the rendering occurs on the Browser. This process can also be referred to as client-side rendering (CSR).
What is the meaning of renderer?
renderer (plural renderers) One who, or that which, renders. A vessel in which lard, tallow, etc., is rendered. (computer graphics) A software or hardware process that generates a visual image from a model.
How do I use renderer 2?
Using Renderer2
Use ElementRef & ViewChild to get the reference to the DOM element, which you want to manipulate. @ViewChild(‘hello’, { static: false }) divHello: ElementRef; Use the methods like setProperty , setStyle etc to change the property, styles of the element as shown below.
How does Angular check lazy loading?
If you want to check how lazy loading works and how lazy loading routing flow, then Augury is the best tool we have. Click on ctrl+F12 to enable the debugger and click on the Augury tab. Click on the router tree. Here, it will show the route flow of our modules.
What is lazy loading in Angular JS?
Lazy loading is performed by allowing the router config to provide the module to load on route execution. This of course relies on you splitting your application into modules. Of course, feel free to check out our previous post on creating exportable feature modules in AngularJS 2.
Why would you use lazy loading modules in Angular app?
Lazy Loading is the technique of loading the module or data on demand. It helps us to better the application performance and reduce the initial bundle size of our files. The initial page loads faster and we can also split the application into the logic chunks which can be loaded on demand.
What is read in ViewChild?
With {read: SomeType} you tell what type should be returned from the element with the #myname template variable. If you don’t provide the read parameter, @ViewChild() returns the. ElementRef instance if there is no component applied, or the. component instance if there is.
What are decorators in Angular?
Decorators are a design pattern that is used to separate modification or decoration of a class without modifying the original source code. In AngularJS, decorators are functions that allow a service, directive or filter to be modified prior to its usage.
What is Ng container and ng-template?
To sum up, ng-content is used to display children in a template, ng-container is used as a non-rendered container to avoid having to add a span or a div , and ng-template allows you to group some content that is not rendered directly but can be used in other places of your template or you code.
Why do we need template reference variables?
Template variables help you use data from one part of a template in another part of the template. Use template variables to perform tasks such as respond to user input or finely tune your application’s forms. A template variable can refer to the following: a DOM element within a template.
When and where @input decorator can be used in a component?
Use @Input decorator and declare those variables which are passed by parent component Html(app. component. html) file’s point 1. When we declare those variable (myinputMsg) with @Input decorator it automatically fetches the value of the parent component variable with the help of @Input decorator.
What are decorators in angular?
Decorators are a design pattern that is used to separate modification or decoration of a class without modifying the original source code. In AngularJS, decorators are functions that allow a service, directive or filter to be modified prior to its usage.