HttpRequest

HttpRequest is injected into any backend method that declares it as a parameter. It gives you access to every piece of contextual data available when an action is triggered: URL parameters, request headers, the serialised component state, app-level state, and the rows the user has selected or clicked.

public interface HttpRequest {

    // Core HTTP
    String path();
    String getParameterValue(String name);
    List<String> getParameterValues(String name);
    List<String> getParameterNames();
    String getHeaderValue(String key);
    List<String> getHeaderValues(String key);

    // Path helpers
    default String lastPathItem()          // last segment of path()
    default String penultimatePathItem()   // second-to-last segment

    // Component state
    default String getString(String key)
    default int getInt(String key)
    default double getDouble(String key)
    default List<Map<String, Object>> getListOfMaps(String key)

    // Typed state
    default <T> T getComponentState(Class<T> componentStateType)
    default <T> T getAppState(Class<T> appStateType)
    default <T> T getParameters(Class<T> rowType)

    // Selection
    default <T> List<T> getSelectedRows(Class<T> rowType)
    default <T> List<T> getSelectedRows(String fieldName, Class<T> rowType)
    default <T> T getClickedRow(Class<T> rowType)

    // Low-level attribute store
    Object getAttribute(String key);
    void setAttribute(String key, Object value);
}

Method reference

Path

Method	Description
`path()`	Full URL path of the current request
`lastPathItem()`	Last `/`-delimited segment of the path — typically a resource ID
`penultimatePathItem()`	Second-to-last segment

URL parameters

Method	Description
`getParameterValue(name)`	First value of a URL query parameter
`getParameterValues(name)`	All values of a multi-valued query parameter
`getParameterNames()`	All parameter names present in the request

Headers

Method	Description
`getHeaderValue(key)`	First value of the named request header
`getHeaderValues(key)`	All values of a multi-valued header

Component state

The component state is the current in-memory form state serialised as a Map. The scalar helpers are convenience wrappers around that map.

Method	Description
`getString(key)`	Read a `String` field from the component state map
`getInt(key)`	Read an `int` field (handles `Integer`, `Long`, and string-encoded numbers)
`getDouble(key)`	Read a `double` field
`getListOfMaps(key)`	Read a `List<Map<String, Object>>` field
`getComponentState(Class<T>)`	Deserialise the entire component state into a typed object

App and action state

Method	Description
`getAppState(Class<T>)`	Deserialise the shared application state into a typed object
`getParameters(Class<T>)`	Deserialise the action-level parameters map into a typed object; returns the raw `Map` when `rowType` is `Map.class`

Row selection

Method	Description
`getSelectedRows(Class<T>)`	All rows checked in the default grid (`crud_selected_items`)
`getSelectedRows(fieldName, Class<T>)`	Rows checked in a named grid field (`{fieldName}_selected_items`)
`getClickedRow(Class<T>)`	The single row the user clicked for a row-level action

Low-level attribute store

Method	Description
`getAttribute(key)`	Read an arbitrary object stored in the request scope
`setAttribute(key, value)`	Store an arbitrary object in the request scope

Examples

Read a header (JWT auth)

This pattern is used in the Changes demo to extract the current user from a Bearer token.

@Toolbar
public CreateReleaseForm createRelease(List<ChangeRow> selectedRows, HttpRequest httpRequest) {
    var auth = httpRequest.getHeaderValue("Authorization");
    var jwt = auth.split(" ")[1];

    String[] chunks = jwt.split("\\.");
    var payload = fromJson(new String(Base64.getUrlDecoder().decode(chunks[1])));
    var user = payload.get("preferred_username").toString();

    return createReleaseForm.withUser(user);
}

Read a URL path segment

@Override
public Component component(HttpRequest httpRequest) {
    var id = httpRequest.lastPathItem();   // e.g. /customers/42  → "42"
    var customer = customerRepository.findById(id).orElseThrow();
    return Form.builder().title(customer.getName()).build();
}

Deserialise typed component state

public record SearchState(String query, String country) {}

@Override
public Object handleAction(String actionId, HttpRequest httpRequest) {
    var state = httpRequest.getComponentState(SearchState.class);
    return searchService.search(state.query(), state.country());
}

Work with selected rows

@Override
public Object handleAction(String actionId, HttpRequest httpRequest) {
    if ("export".equals(actionId)) {
        var rows = httpRequest.getSelectedRows(CustomerRow.class);
        exportService.export(rows);
    }
    return null;
}

Read a query parameter

@Override
public Component component(HttpRequest httpRequest) {
    var page = httpRequest.getParameterValue("page");
    return new Text("Page: " + page);
}