Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[10] *}

/// note | Nota

Um parâmetro de path é sempre obrigatório, pois precisa fazer parte do path. Mesmo que você o declare como `None` ou defina um valor padrão, isso não afetaria nada, ele ainda seria sempre obrigatório.

///

## Ordene os parâmetros de acordo com sua necessidade { #order-the-parameters-as-you-need }

/// tip | Dica

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>ut.simple</groupId>
  <artifactId>dependency</artifactId>
  <version>1.0</version>

  <name>Simple Unit Test Dependency</name>

        <my.filter.value>hello</my.filter.value>
    </properties>

    <profiles>
        <profile>
            <id>two-conditions</id>
            <activation>
                <file>
                    <exists>simple.xml</exists>
                </file>
                <property>
                    <name>myproperty</name>
                    <value>test</value>
                </property>
            </activation>

* (Optionnellement) comprendre ce que vous, en tant que développeur, devez savoir sur HTTPS.
* Configurer un cluster en mode Docker Swarm avec HTTPS automatique, même sur un simple serveur à 5 dollars US/mois. En environ **20 min**.
* Générer et déployer une application **FastAPI** complète, en utilisant votre cluster Docker Swarm, avec HTTPS, etc. En environ **10 min**.

     * @param simpleMessage
     *            Simple message with arguments expanded
     * @return Message with message code
     */
    public static String getFormattedMessage(final String messageCode, final String simpleMessage) {
        return "[" + messageCode + "]" + simpleMessage;
    }

    /**
     * Expands arguments and returns a simple message without a message code.
     *
     * @param messageCode

 * interfere with session-based authentication schemes that require cookies.
 *
 * As persistence, implementations of this interface must also provide storage of cookies. Simple
 * implementations may store cookies in memory; sophisticated ones may use the file system or
 * database to hold accepted cookies. The [cookie storage model][rfc_6265_53] specifies policies for
 * updating and expiring cookies.

  <modelVersion>4.0.0</modelVersion>
  <groupId>org.apache.maven.embedder</groupId>
  <artifactId>simple-project</artifactId>
  <version>1.0-SNAPSHOT</version>
  <name>simple-project</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>

    fields `username` and `password`.

    All the initialization parameters are extracted from the request.

    Read more about it in the
    [FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).

    ## Example

    ```python
    from typing import Annotated

    from fastapi import Depends, FastAPI

Or you might have any other way to communicate with the WebSocket endpoint.

---

But for this example, we'll use a very simple HTML document with some JavaScript, all inside a long string.

This, of course, is not optimal and you wouldn't use it for production.

In production you would have one of the options above.