How to get UID from an Angular fire store Document without snapshot

Question

let say I have a collection named Countries and a doc looks like below

{
  name: "Pakistan"
  //other field removed to focus on problem only
}

and a Collection names Cities which doc have above country field reference looks like

{
  name: "Karachi",
  //other field removed to focus on problem only
  city: "3FbRFiWB4DmfdcxDdei3" //reference of country document
}

now I am displaying the countries and cities as ordered drop down menus as user select country then the next drop down displays filtered cities

let countryRef = this.angularFireStore.collection('Countries', ref => ref);
let countries = countryRef.valueChanges();

and html binding looks like

let country of country | async"

Here is the actual problem on any change or select event of user I have to pass id of country to populated filtered cities based of selected country but I can't got id in country. How to achieve this any help will be greatly appreciated.

NOTE: I know I can got id and other metadata by getting snapshot change but that response very late I just want id field in reference binding for editing or updating Documents.

use `.snapshotChanges()` instead of `countryRef.valueChanges();`. check this [answer](https://stackoverflow.com/questions/47221248/how-to-retrieve-the-id-of-a-single-firestore-document/47223346#47223346). Another option would be save the id with the country doc while creating it. — Hareesh, Feb 26 '18 at 10:40
@Hareesh thanks one more thing, how can I update query ref dynamically when country field selected. i.e `this.angularFireStore.collection('Cities', ref => ref.where('country', '==', 'selectedcountryID'));` — Abdul Hameed, Feb 26 '18 at 10:57
@Hareesh `.snapshotChanges()` is very slow other wise I will go with it, didn't you read my `Note` section — Abdul Hameed, Feb 26 '18 at 11:02

Hareesh · Accepted Answer · 2018-02-26T11:39:43.477

As you said you don't want to use .snapshotChanges() and get id with .valueChanges() you need to store it while creating the doc. Do this in your add country function

this.tempId = this.angularFireStore.createId();

const newCountry = {
      id:this.tempId,
      name:'Karachi'
      //other fields...
    }

this.angularFireStore.collection('Countries').doc(this.tempId).set(newCountry).then(res => {
  console.log('country added')
}).catch(err => {
  console.log('error adding country',err)
});

How to get UID from an Angular fire store Document without snapshot

1 Answers1