Getting count of contacts correct but getting null values for contacts in Ionic 4

Ionic Native
1 
import { Contacts } from '@ionic-native/contacts/ngx';

constructor( private contactsPlugin: Contacts ) { }

this.contactsPlugin.find(["displayName", "phoneNumbers","photos"], {multiple: true, hasPhoneNumber: true})
      .then((contacts) => {
        console.log("Length: ", contacts.length);
        for(let i=0; i < contacts.length; i++){
          console.log('... ',contacts[i]);
        }
      }, 
      (error) => {
        console.error("Contacts error: ", error)
      })

I am using,
“cordova-plugin-contacts”: “3.0.1”,
“@ionic-native/contacts”: “^5.0.0”

2

First, make sure the platform is ready before calling it.

Second, for iOS you need to adjust the config.xml to request permission to access your contacts.

3

Thank you for reply. I tried after device ready but still not working.

document.addEventListener("deviceready", () => {
      this.contactsPlugin.find(["displayName", "phoneNumbers","photos"], {multiple: true, hasPhoneNumber: true})
      .then((contacts) => {
        console.log("Length: ", contacts.length);
        for(let i=0; i < contacts.length; i++){
          console.log('... ',contacts[i]);
          if ( contacts[i].displayName != null ) {
            console.log("--> ", contacts[i].displayName );
          }
        }
      }, 
      (error) => {
        console.error("Contacts error: ", error)
      })

    });
4

Solved:

import { Contacts } from '@ionic-native/contacts/ngx';

declare var navigator: any;
@Component({
  selector: 'assignment',
  templateUrl: './assignment.page.html',
  styleUrls: ['./assignment.page.scss']
})

async getContacts() {
     await document.addEventListener("deviceready", () => {
 
      navigator.contacts.find(
        [navigator.contacts.fieldType.displayName],
        gotContacts,
        errorHandler);

        function errorHandler(e) {
          console.log("errorHandler: "+e);
        }
        
        function gotContacts(deviceContacts) {
        console.log("gotContacts, number of results " + deviceContacts.length);
          for(var i=0, len = deviceContacts.length; i<len; i++) {
                console.log("Contact >>>  ", deviceContacts[i]);
           }
       }
   }
}