# 表单模型

您可以使用 **Pydantic 模型**在 FastAPI 中声明**表单字段**。

/// info

要使用表单，需预先安装 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a> 。

确保您创建、激活一个[虚拟环境](../virtual-environments.md){.internal-link target=_blank}后再安装。

```console
$ pip install python-multipart
```

///

/// note

自 FastAPI 版本 `0.113.0` 起支持此功能。🤓

///

## 表单的 Pydantic 模型

 * under the License.
 */
package org.apache.maven.api.services;

import org.apache.maven.api.annotations.Experimental;

/**
 * The Exception class throw by the {@link ProjectBuilder} service.
 *
 * @since 4.0.0
 */
@Experimental
public class ModelBuilderException extends MavenException {

    private final ModelBuilderResult result;

    /**

import java.util.Objects;

/**
 * Wraps an ordinary {@link File} as a source.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services} instead
 */
@Deprecated(since = "4.0.0")
public class FileSource implements Source {
    private final Path path;

    private final int hashCode;

    /**
     * Creates a new source backed by the specified file.
     *

        InternalSession.associate(rss, this.session);
        sessionScope.enter();
        sessionScope.seed(InternalMavenSession.class, InternalMavenSession.from(this.session));
    }

    private Project project(Artifact artifact) {
        return session.getService(ProjectBuilder.class)
                .build(ProjectBuilderRequest.builder()
                        .session(session)

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

/// note | Nota

Cuando instalas con `pip install "fastapi[standard]"` viene con algunas dependencias opcionales estándar por defecto, incluyendo `fastapi-cloud-cli`, que te permite hacer deploy a <a href="https://fastapicloud.com" class="external-link" target="_blank">FastAPI Cloud</a>.

## Detalhes técnicos { #technical-details }

A classe `BackgroundTasks` vem diretamente de <a href="https://www.starlette.dev/background/" class="external-link" target="_blank">`starlette.background`</a>.

# CORS (Cross-Origin Resource Sharing) { #cors-cross-origin-resource-sharing }

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">Понятие CORS или "Cross-Origin Resource Sharing"</a> относится к ситуациям, при которых запущенный в браузере фронтенд содержит JavaScript-код, который взаимодействует с бэкендом, находящимся на другом "источнике" ("origin").

## Источник { #origin }

     * When specified, only the listed types will be available for injection,
     * even if the class implements or extends other types. If empty, the
     * default behavior is to make all supertypes available for injection.
     * <p>
     * Example:
     * <pre>
     * {@literal @}Typed({Service.class, Monitored.class})
     * public class ServiceImpl implements Service, Monitored, Logging {

        request.setModelSource(new StringModelSource(BASE1));
        request.setModelResolver(new CycleInImportsResolver());

        assertThrows(ModelBuildingException.class, () -> builder.build(request));
    }

    static class CycleInImportsResolver extends BaseModelResolver {
        @Override
        public ModelSource resolveModel(Dependency dependency) throws UnresolvableModelException {

        }
    }

    public static class Build {}

    public static class Dependency {
        private String artifactId;

        public String getArtifactId() {
            return artifactId;
        }

        public void setArtifactId(String id) {
            artifactId = id;
        }
    }

    public static class Scm {
        private String connection;