How do i retrieve data with its key firebase

Question

Lets say we have a database:

Recipes
   recipe_key(some uniq key generated when data pushed)
          ingredients:pepper

how do i retrieve pepper value with recipe_key ? I checked documentation of angularfire2 it says use snapshotchanges but with this code i can only get "Recipes".I guess i need to go 1 more layer down ?

    constructor(afDb: AngularFireDatabase) {
      afDb.object('/recipes/').snapshotChanges().map(action => {
        const $key = action.payload.key;
        const data = { $key, ...action.payload.val() };
        return data;
      }).subscribe(item => console.log(item.$key));
    }

Answer 1

The documentation is correct, you should be using snapshot changes so that you can get the key property from the payload object.

Looking at your code I believe you forgot to add the key to the object() method of the AngularFireDatabase

const recipeKey = '<your-push-key>';
afDb.object(`/recipes/${recipeKey}`).snapshotChanges().map(action => {
    const $key = action.payload.key;
    const data = { $key, ...action.payload.val() };
    return data;
}).subscribe(item => console.log(item.$key));

If you want to retrieve a list with the $key property you can use this method.

afDb.list(`/recipes`).snapshotChanges().map(actions => {
    return actions.map(action => {
        const $key = action.payload.key;
        const data = { $key, ...action.payload.val() };
        return data;
    });
}).subscribe(items => console.log(items));