</blockquote>

## Investigation { #investigation }

# Classes as Dependencies { #classes-as-dependencies }

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example { #a-dict-from-the-previous-example }

In the previous example, we were returning a `dict` from our dependency ("dependable"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

But at some point, there was no other option than creating something that provided all these features, taking the best ideas from previous tools, and combining them in the best way possible, using language features that weren't even available before (Python 3.6+ type hints).

## Previous tools { #previous-tools }

### <a href="https://www.djangoproject.com/" class="external-link" target="_blank">Django</a> { #django }

And also the docs about <a href="https://strawberry.rocks/docs/integrations/fastapi" class="external-link" target="_blank">Strawberry with FastAPI</a>.

## Older `GraphQLApp` from Starlette { #older-graphqlapp-from-starlette }

Previous versions of Starlette included a `GraphQLApp` class to integrate with <a href="https://graphene-python.org/" class="external-link" target="_blank">Graphene</a>.

                    val versionsOfMinor = entry.value.sortedByDescending { VersionNumber.parse(it) }
                    if (idx < versionsByMinor.size - 1) {
                        // Latest of the previous minor
                        add(versionsOfMinor.first())
                    } else {
                        // Current minor
                        val versionsByPatch = versionsOfMinor

///

## Shortcut to remember the names { #shortcut-to-remember-the-names }

Let's see the previous example again:

{* ../../docs_src/response_status_code/tutorial001_py39.py hl[6] *}

`201` is the status code for "Created".

But you don't have to memorize what each of these codes mean.

{* ../../docs_src/templates/tutorial001_py39.py hl[4,11,15:18] *}

/// note

Before FastAPI 0.108.0, Starlette 0.29.0, the `name` was the first parameter.

Also, before that, in previous versions, the `request` object was passed as part of the key-value pairs in the context for Jinja2.

///

/// tip

starting in Go 1.21, a main package's source files
can include one or more `//go:debug` directives at the top of the file
(preceding the `package` statement).
The `godebug` lines in the previous example would be written:

	//go:debug default=go1.21
	//go:debug panicnil=1
	//go:debug asynctimerchan=0

Starting in Go 1.21, the Go toolchain treats a `//go:debug` directive

# Классы как зависимости { #classes-as-dependencies }

Прежде чем углубиться в систему **Внедрения Зависимостей**, давайте обновим предыдущий пример.

## `dict` из предыдущего примера { #a-dict-from-the-previous-example }

В предыдущем примере мы возвращали `dict` из нашей зависимости:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

Но затем мы получаем `dict` в параметре `commons` *функции-обработчика пути*.

</div>

## Update the App with Multiple Models { #update-the-app-with-multiple-models }

Now let's **refactor** this app a bit to increase **security** and **versatility**.

If you check the previous app, in the UI you can see that, up to now, it lets the client decide the `id` of the `Hero` to create. 😱