CODEWITHSUNDEEP
angulartypescriptangular8
user12425844
user12425844

Reputation:

Angular: Using ViewChild and Input at the Same time, Side Effects or Best practice?

Would there be any errors or collision if using ViewChild and Input at the same time? Or is it recommended practice in general?

Currently have Parent and Child component.

Requirements:

a) Parent needs to tell child component to conduct many things: mark form as touched, update values, manipulate the DOM, remove validators, etc. Things which are harder with @Input().

b) Also needs to apply input, however looking at resource here, ViewChild vs Input/Ouput - Angular Best Practices

ViewChild will not display child component View data changes, from ongoing inputs with NgOnChanges(). However, using @Input() will render changes in the Input/parameter.

So if using both options, ViewChild And Input to extract both benefits, wondering if it may cause errors later? Will Native Angular 8 face any channel communication issues if it has these two ways of communicating with child?

Other Resource :

angular's @input vs viewchild for sending data from parent to child component

Upvotes: 2

Views: 1672

Answers (1)

Eliseo
Eliseo

Reputation: 58019

The link you indicate is a bit old. In my opinion, the use of viewChild is usefull when we want to use a method or function of the child(*), or change his aspect. For control a variable or a FormGroup or formControl my best bet is use @Input.

Remember that, when we pass an object to a child in a Input, there are an unique object, so parent and children has the value when any change happens -in children or in parent-, e.g. if we pass a FormGroup, you can mark as touched, remove/add validators, use setValue... from parent or form children. About @Input is true that if you has a "input fixed" -you pass a variable that not change- ,as 

<child greet="Hello word"></child>

You should use @Attribute in constructor, NOT input

constructor(@Attribute('greet') greet){}

(*)you can use a input with a setter, but in this case I like much more use viewChild or a variable reference

Upvotes: 3

Related Questions