# Advanced Dependencies { #advanced-dependencies }

## Parameterized dependencies { #parameterized-dependencies }

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

practice is to set conventions in a plugin (2). This keeps the underlying object "dumb", so it can be reused in multiple contexts and doesn't contain any special information about how conventions are calculated or what they could be.  In the wild, we've seen some objects set conventions in the object's constructor (3), but this can lead to unexpected assumptions or coupling between plugins.

For external plugins, it's difficult for an object to be used outside the application of a plugin, so...

///

/// check | **FastAPI**'a nasıl ilham oldu?

Hug, APIStar'ın çeşitli kısımlarında esin kaynağı oldu ve APIStar'la birlikte en umut verici bulduğum araçlardan biriydi.

**FastAPI**, Python tip belirteçlerini kullanarak parametre belirlemede ve API'ı otomatık tanımlayan bir şema üretmede de Hug'a esinlendi.

   * simultaneously adopted and removed.
   */
  private val connections = ConcurrentLinkedQueue<RealConnection>()

  init {
    // Put a floor on the keep alive duration, otherwise cleanup will spin loop.
    require(keepAliveDuration > 0L) { "keepAliveDuration <= 0: $keepAliveDuration" }
  }

  fun idleConnectionCount(): Int =
    connections.count {
      it.withLock { it.calls.isEmpty() }
    }

Podrías **llamar** a esa misma función en **otros lugares** sin FastAPI, y **funcionaría como se espera**. Si hay un parámetro **requerido** (sin un valor por defecto), tu **editor** te avisará con un error, **Python** también se quejará si lo ejecutas sin pasar el parámetro requerido.

/// info | Info

Selbst, nachdem OpenAPI 3.1.0 veröffentlicht wurde, mit dieser neuen, einfacheren Integration mit JSON Schema, unterstützte Swagger UI, das Tool, das die automatische Dokumentation bereitstellt, eine Zeit lang OpenAPI 3.1.0 nicht (das tut es seit Version 5.0.0 🎉).

test:rbe_base --test_env=USER=anon

# TODO(kanglan): Check if we want to merge rbe_linux into rbe_linux_cpu.
common:rbe_linux --config=rbe_base
common:rbe_linux --action_env=PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/go/bin"
# Non-rbe settings we should include because we do not run configure
common:rbe_linux --config=avx_linux
# TODO(gunan): Check why we need this specified in rbe, but not in other builds.

FB2A          ; mapped                 ; 05E9 05C1     # 1.1  HEBREW LETTER SHIN WITH SHIN DOT
FB2B          ; mapped                 ; 05E9 05C2     # 1.1  HEBREW LETTER SHIN WITH SIN DOT
FB2C          ; mapped                 ; 05E9 05BC 05C1 #1.1  HEBREW LETTER SHIN WITH DAGESH AND SHIN DOT
FB2D          ; mapped                 ; 05E9 05BC 05C2 #1.1  HEBREW LETTER SHIN WITH DAGESH AND SIN DOT

  // the "short hash".
  //
  // The `keys`, `values`, and `entries` arrays always have the same size as each other. They can be
  // seen as fields of an imaginary `Entry` object like this:
  //
  // class Entry {
  //    int hash;
  //    Entry next;
  //    K key;
  //    V value;
  // }
  //

You can learn how to use them and how they are integrated into **FastAPI** later in the **Advanced User Guide**.

## Recap { #recap }

With what you have seen up to now, you can set up a secure **FastAPI** application using standards like OAuth2 and JWT.

In almost any framework handling the security becomes a rather complex subject quite quickly.