Solving Cannot find a differ supporting object ‘someObject’ of type ‘object’. NgFor only supports binding to Iterables such as Arrays

If you are working with Angular and you encounter the error “Cannot find a differ supporting object ‘someObject’ of type ‘object’. NgFor only supports binding to Iterables such as Arrays”, you might be wondering what it means and how to solve it. In this blog post, I will explain the cause of this error and show you some possible solutions.

The error occurs when you try to use the *ngFor directive to loop over an object that is not iterable, such as a plain JavaScript object. The *ngFor directive expects an iterable object, such as an array, a set, or a map, that has a length property and can be accessed by index. A plain object does not have these properties and cannot be iterated over by *ngFor.

One way to solve this error is to convert the object into an array before passing it to *ngFor. You can use the Object.keys(), Object.values(), or Object.entries() methods to get an array of the object’s keys, values, or key-value pairs, respectively. For example, if you have an object like this:

someObject = {
name: 'John',
age: 25,
occupation: 'Developer'
};

You can convert it into an array of values like this:

someArray = Object.values(someObject);

And then use *ngFor to loop over the array:

<div *ngFor="let value of someArray">
{{ value }}
</div>

Another way to solve this error is to use a custom pipe that transforms the object into an iterable. You can create a pipe that implements the PipeTransform interface and uses the IterableDiffers service to track changes in the object. The pipe should return an array of key-value pairs that can be used by *ngFor. For example, you can create a pipe like this:

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

@Pipe({
name: 'keyValue'
})
export class KeyValuePipe implements PipeTransform {
constructor(private differs: IterableDiffers) {}

differ: KeyValueDiffer<string, any>;
cached: any[];

transform(value: any): any[] {
if (!this.differ) {

this.differ = this.differs.find(value).create();
}

const changes = this.differ.diff(value);

if (changes) {

this.cached = [];
changes.forEachItem(item => {
this.cached.push({ key: item.key, value: item.currentValue });
});
}

return this.cached;
}
}

And then use it in your template like this:

<div *ngFor="let item of someObject | keyValue">
{{ item.key }}: {{ item.value }}
</div>