var messages = document.getElementById('messages')
                var message = document.createElement('li')
                var content = document.createTextNode(event.data)
                message.appendChild(content)
                messages.appendChild(message)
            };
            function sendMessage(event) {
                var input = document.getElementById("messageText")

    /**
     * Gets the base href from the document's BASE tag.
     *
     * @param document the document to extract base href from
     * @return the base href URL, or null if not found
     */
    protected String getBaseHref(final Document document) {
        try {
            final XPathNodes list = getXPathAPI().selectNodeList(document, "//BASE");
            if (list.size() > 0) {
                final Node node = list.get(0);

```

## 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()

                new String[] { SuggestConstants.DEFAULT_ROLE }, null, SuggestItem.Kind.DOCUMENT);

        SuggestItem item2 = new SuggestItem(new String[] { "テスト" }, readings, new String[] { "content" }, 2, 0, -1, new String[] { "tag2" },
                new String[] { SuggestConstants.DEFAULT_ROLE }, null, SuggestItem.Kind.DOCUMENT);

        SuggestItem[] mergedItems = writer.mergeItems(new SuggestItem[] { item1, item2 });

    //                                                                      ==============
    /**
     * Handles document redirection requests.
     * Validates the document ID, logs click events if enabled, and redirects
     * to the target URL or serves file content directly if configured.
     *
     * @param form the go form containing document ID and tracking parameters
     * @return action response for redirection or content streaming

            ReadingConverter readingConverter, Normalizer normalizer);

    /**
     * Parses a document and extracts suggest items based on the provided fields and converters.
     *
     * @param document The document to parse, represented as a map of field names to values.
     * @param fields The fields to extract from the document.
     * @param tagFieldNames The names of the fields that contain tags.

        }

    }

    /**
     * Calculates the document expiration date based on crawling configuration.
     * If the config has a timeToLive value, calculates expiration from current time.
     * Otherwise, returns the stored document expiration time.
     *
     * @param config the crawling configuration containing time-to-live settings
     * @return the document expiration date, or null if no expiration is set
     */

     * This includes namespace updates and module conversion using domtrip.
     * Returns the upgraded document.
     */
    private Document performModelUpgrade(
            Document pomDocument, UpgradeContext context, String currentVersion, String targetModelVersion) {
        // Create Editor from domtrip Document
        Editor editor = new Editor(pomDocument);

        // Update model version element

/**
 * The search form for Boost Document.
 */
public class SearchForm {

    /**
     * Default constructor for SearchForm.
     */
    public SearchForm() {
    }

    /**
     * The URL expression field for boost document configuration.
     */
    public String urlExpr;

    /**
     * The boost expression field for document scoring.
     */
    public String boostExpr;

        return new String(buf);
    }

    /**
     * Converts a {@link Document} to a string.
     *
     * @param document
     *            The document. Must not be {@literal null}.
     * @return The converted string.
     */
    public static String toString(final Document document) {
        assertArgumentNotNull("document", document);

        final StringBuilder buf = new StringBuilder(1000);