---
title: 🔴 Typed ContextOutlet
description: Challenge 4 is about strongly typing ngContextOutlet directives
sidebar:
  order: 201
---

:::note
WIP: The following documentation will be reviewed and improved. However, you can still take on the challenge. If you don't understand a certain part, please feel free to reach out or create an issue.
:::

<div class="chip">Challenge #4</div>

## Information

Angular offer the static function **ngTemplateContextGuard** to strongly type structural directive.

However the context of **NgTemplateOutlet** type is **Object**. But which the help of the above guard, we can improve that behavior.

## Statement

In this exercice, we want to learn how to strongly typed our ng-template in our AppComponent.

This exercice has two level of complexity.

### Level 1: known Interface

Currently we have the following piece of code.

![Unkown Person](../../../../assets/4/unknown-person.png 'Unkown Person')

As we can see, name is of type "any". We want to infer the correct type.

### Level 2: generic Interface

Currently we have the following piece of code.

![Unkown Student](../../../../assets/4/unknown-student.png 'Unkown Student')

As we can see, student is of type "any". We want to infer the correct type.

But in this part, we can pass to ListComponent, a list of **any object**. And we still want the correct type to be infered.

---

:::note
Start the project by running: `npx nx serve context-outlet-type`.
:::

:::tip[Reminder]
Your PR title must start with <b>Answer:4</b>.
:::

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