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. a directive.
What is a template variable in Angular?
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. a directive.
What is a template reference variable?
The Template reference variable is a reference to any DOM element, component or a directive in the Template . We can use it elsewhere in the template. We can also pass it to a method in the component. It can contain a reference to elements like h1 , div , etc.
Why do we need template reference variables in Angular?
Angular’s template reference variables provide a useful API through which you can interact with DOM elements and child components directly in your Angular code .
What are template expressions in Angular?
In Angular, template expressions are computations or assignments done in the template inside the interpolation curly braces . This expression is considered as local and only exist inside the template. A template statement responds to an event raised by a binding target such as an element, component, or directive.
What is ViewChild in Angular?
A ViewChild is a component, directive, or element as a part of a template . If we want to access a child component, directive, DOM element inside the parent component, we use the decorator @ViewChild() in Angular.
What does means in Angular?
Means safe navigation operator . From Docs. The Angular safe navigation operator (?.) is a fluent and convenient way to guard against null and undefined values in property paths. Here it is, protecting against a view render failure if the currentHero is null.
How do you use a reference variable in a template?
- Create an Angular app to be used.
- Create the input element and add the template reference to this input field using # tag.
- Bind this template reference inside the button click method “changeTitle()”.
What is local reference in Angular?
Instead of two-way binding, we can easily fetch a value of any input through local references in Angular. Local references can be fetched directly from the component template and into the component typescript class. Lets check out how do we use local references.
What is ViewChild decorator in Angular?
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.
What is Event binding in Angular?
Event binding lets you listen for and respond to user actions such as keystrokes, mouse movements, clicks, and touches .
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 TemplateRef?
TemplateRef is a class and the way to reference the ng-template in the component or directive class . Using the TemplateRef we can manipulate the template from component code. Remember ng-template is a bunch of HTML tags enclosed in a HTML element <ng-template>
What does => mean in Angular?
solocupjazz. 1y. It’s coercion to a boolean value . Means that you want to make sure your resulting value is either true or false, not undefined or [ ]. For example, you’re passing the resulting value to something that expects a boolean and nothing else.
What is CLI in Angular?
The Angular CLI is a command-line interface tool that you use to initialize, develop, scaffold, and maintain Angular applications directly from a command shell.
What is * ngFor used for?
The *ngFor directive is used to repeat a portion of HTML template once per each item from an iterable list (Collection) . The ngFor is an Angular structural directive and is similar to ngRepeat in AngularJS. Some local variables like Index, First, Last, odd and even are exported by *ngFor directive.
