up.util up.util.isBlank.key

JavaScript property

This property contains the name of a method that user-defined classes may implement to hook into the up.util.isBlank() protocol.

Example

We have a user-defined Account class that we want to use with up.util.isBlank():

class Account {
  constructor(email) {
    this.email = email
  }

  [up.util.isBlank.key]() {
    return up.util.isBlank(this.email)
  }
}

Note that the protocol method is not actually named 'up.util.isBlank.key'. Instead it is named after the value of the up.util.isBlank.key property. To do so, the code sample above is using a computed property name in square brackets.

We may now use Account instances with up.util.isBlank():

let foo = new Account('foo@foo.com')
let bar = new Account('')

console.log(up.util.isBlank(foo)) // prints false
console.log(up.util.isBlank(bar)) // prints true