Angular Directives — #3
Hey folks,
Let's talk in this chapter about Angular Directives.
Introduction
Directives are like markers on DOM element that communicate to Angular to include a specific behavior.
There three types of directives on Angular:
Attributes directives: Change the appearance or the behavior of an element, component or another directive, as ngClass and ngStyle;
Structural directives: Modify the layout adding or removing DOM elements, as ngIf and ngFor;
Components: Are directives with a model
Starting the app on your terminal:
ng new diretivasPoc
Let's create a app that we can know a bit the directives that we will talk on this article:
Begin with ngIf:
It is a directive that allow us to change a page from a conditional declaration and that supposed to mean that put a ngIf in an element or component we can create or remove this element in the condition we provide:
To sum up convert a furnished value to an equivalent to true or false…after decides if show or not the element.
ngSwitch
It is a directive that show an element of a group in basis of a condition. It uses the directives ngSwitchCase and ngSwitchDefault:
Set a variable and uses in .html and setup below.
The result will be something like this:
ngFor
Do you know when we view a table list with a lot of information?
This happens with the help with a repetition loop that create all data one by one…
So the ngFor is a right tool to have on your sleeve.
How use the tool?
As below, we have a list to iterate:
We can present the data as a list or in a table list:
Look how we see this:
ngClass
It is a directive that allows you define a class dynamically from Dom element.
Let's on real how works:
Note that if !isFavorite show the icon (bi-star), else isFavorite (bi-star-fill)
ngStyle
It is used to add style in DOM element, look bellow:
On this example, I was far away using Inputs two way data binding to change the color font and size:
And this is it guys, this is a resume of how works with this basics directives. Considerer that we have too custom directives that allows you to create your own rules.
Take a look on my Github on this repo.
See you all on the next….byeee