How to iterate object keys using *ngFor

Question

I want to iterate [object object] using *ngFor in Angular 2.

The problem is the object is not array of object but object of object which contains further objects.

{

  "data": {
    "id": 834,
    "first_name": "GS",
    "last_name": "Shahid",
    "phone": "03215110224",
    "role": null,
    "email": "[e-mail]",
    "picture": **{ <-- I want to get thumb: url but not able to fetch that**
      "url": null,
      "thumb": {
        "url": null
      }
    },
    "address": "Nishtar Colony",
    "city_id": 2,
    "provider": "email",
    "uid": "[e-mail]"
  }
}

I know we can use pipe to iterate the object but how we can iterate further from object to object means data->picture->thum:url.

Answer 1

Angular 6.0.0

https://github.com/angular/angular/blob/master/CHANGELOG.md#610-beta1-2018-06-13

introduced a KeyValuePipe

@Component({
  selector: 'keyvalue-pipe',
  template: `<span>
    <p>Object</p>
    <div *ngFor="let item of object | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
    <p>Map</p>
    <div *ngFor="let item of map | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
  </span>`
})
export class KeyValuePipeComponent {
  object: {[key: number]: string} = {2: 'foo', 1: 'bar'};
  map = new Map([[2, 'foo'], [1, 'bar']]);
}

original

You can use a pipe

@Pipe({ name: 'keys',  pure: false })
export class KeysPipe implements PipeTransform {
    transform(value: any, args: any[] = null): any {
        return Object.keys(value)//.map(key => value[key]);
    }
}

<div *ngFor="let key of objs | keys">

See also How to iterate object keys using *ngFor?

Answer 2

You have to create custom pipe.

import { Injectable, Pipe } from '@angular/core';
@Pipe({
   name: 'keyobject'
})
@Injectable()
export class Keyobject {

transform(value, args:string[]):any {
    let keys = [];
    for (let key in value) {
        keys.push({key: key, value: value[key]});
    }
    return keys;
}}

And then use it in your *ngFor

*ngFor="let item of data | keyobject"

Answer 3

i would do this:

<li *ngFor="let item of data" (click)='onclick(item)'>{{item.picture.url}}</li>

Answer 4

I know this question is already answered but I have one solution for this same.

You can also use Object.keys() inside of *ngFor to get required result.

I have created a demo on stackblitz. I hope this will help/guide to you/others.

CODE SNIPPET

HTML Code

<div *ngFor="let key of Object.keys(myObj)">
  <p>Key-> {{key}} and value is -> {{myObj[key]}}</p>
</div>

.ts file code

Object = Object;

myObj = {
    "id": 834,
    "first_name": "GS",
    "last_name": "Shahid",
    "phone": "1234567890",
    "role": null,
    "email": "[e-mail]",
    "picture": {
        "url": null,
        "thumb": {
            "url": null
        }
    },
    "address": "XYZ Colony",
    "city_id": 2,
    "provider": "email",
    "uid": "[e-mail]"
}

Answer 5

I think the most elegant way to do that is to use the javascript Object.keys like this:

in the Component pass Object to template:

Object = Object;

then in the template:

<div *ngFor="let key of Object.keys(objs)">
   my key: {{key}}
   my object {{objs[key] | json}} <!-- hier I could use ngFor again with Object.keys(objs[key]) -->
</div>

Answer 6

1.Create a custom pipe to get keys.

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'keys'
})
export class KeysPipe implements PipeTransform {

  transform(value: any, args?: any): any {
    return Object.keys(value);
  }
}

2. In angular template file, you can use *ngFor and iterate over your object object

<div class ="test" *ngFor="let key of Obj | keys">
    {{key}}
    {{Obj[key].property}
<div>