```

## Advanced Usage

### Index from Existing Documents

```java
import org.codelibs.fess.suggest.index.contents.document.ESSourceReader;

// Index suggestions from existing Elasticsearch documents
DocumentReader reader = new ESSourceReader(
    client,
    suggester.settings(),
    "content-index",        // source index
    "document"             // document type
);

suggester.indexer()

    }

    @Test
    public void testKindEnum() {
        // Test Kind enum
        assertEquals("query", SuggestItem.Kind.QUERY.toString());
        assertEquals("document", SuggestItem.Kind.DOCUMENT.toString());
        assertEquals("user", SuggestItem.Kind.USER.toString());
    }

    @Test
    public void testGetUpdatedSource() {
        // Test getUpdatedSource method

///

/// info

Of course, the actual `Content-Type` header, status code, etc, will come from the `Response` object you returned.

///

### Document in OpenAPI and override `Response` { #document-in-openapi-and-override-response }

    /** List of rewrite rules for document settings */
    protected final List<UnaryOperator<String>> docSettingRewriteRuleList = new ArrayList<>();

    /** List of rewrite rules for document mappings */
    protected final List<UnaryOperator<String>> docMappingRewriteRuleList = new ArrayList<>();

    /** Whether to use pipelines for document processing */
    protected boolean usePipeline = false;

This code won't be executed in your app, we only need it to *document* how that *external API* should look like.

But, you already know how to easily create automatic documentation for an API with **FastAPI**.

        urlFilter.init(sessionId);

        urlFilter.addInclude(".*\\.PDF$");

        // Test case sensitivity
        assertFalse(urlFilter.match("https://example.com/document.pdf"));
        assertTrue(urlFilter.match("https://example.com/document.PDF"));
    }

    /**
     * Test very long URL handling
     */
    public void test_veryLongUrl() {
        String sessionId = "test-session-020";

            }
        }

        return attrs;
    }
}

/**
* HTML API: If current script has container(s) specified, initialise Termynal.
*/
if (document.currentScript.hasAttribute('data-termynal-container')) {
    const containers = document.currentScript.getAttribute('data-termynal-container');
    containers.split('|')
        .forEach(container => new Termynal(container))

///

**FastAPI** will do the automatic conversion from the request, so that the parameter `item` receives its specific content and the same for `user`.

It will perform the validation of the compound data, and will document it like that for the OpenAPI schema and automatic docs.

## Singular values in body { #singular-values-in-body }

The string will be checked to be a valid URL, and documented in JSON Schema / OpenAPI as such.

## Attributes with lists of submodels { #attributes-with-lists-of-submodels }

You can also use Pydantic models as subtypes of `list`, `set`, etc.:

{* ../../docs_src/body_nested_models/tutorial006_py310.py hl[18] *}

This will expect (convert, validate, document, etc.) a JSON body like:

```JSON hl_lines="11"
{

///

FastAPI will now:

* **Validate** the data making sure that the max length is 50 characters
* Show a **clear error** for the client when the data is not valid
* **Document** the parameter in the OpenAPI schema *path operation* (so it will show up in the **automatic docs UI**)

## Alternative (old): `Query` as the default value { #alternative-old-query-as-the-default-value }