How to check if text area is empty or not in angular 2?

I am able to get the data with jquery or javascript,but i don't want to use that. i want to use it in angular 2,Can any body help me?

Use [ngModel] if you want to do it more "Angularish"...

<textarea [(ngModel)]="textValue" (ngModelChange)="textAreaEmpty()"></textarea>

TS:

textValue: string = '';

textAreaEmpty(){
  if (this.textValue != '') {
    console.log(this.textValue);
  }
}

textValue is not a value in this case. It's the whole input element so if you'd like to check if it has it's own value, you need to change your html as follows:

<textarea (change)="textAreaEmpty(textValue.value)" #textValue></textarea>

Validation for new-lines, white-spaces or null

if(value.trim().length === 0)
   console.log('No input found')

Run code snippet to test

insert new-lines and white-spaces but you'll not get any output on focus-out from input field

document.getElementsByName("text")[0].addEventListener('change', onChange);

function onChange(){
  if (this.value.trim().length != 0) {
       console.log('Here is your output: ')
       console.log(this.value)
   }
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>

<textarea name="text" rows="3" class="form-control" placeholder="Write and check"></textarea>