com.vaadin.flow.server.communication.

java.lang.Object
- com.vaadin.flow.server.SynchronizedRequestHandler
- - com.vaadin.flow.server.BootstrapHandler
  - - com.vaadin.flow.server.communication.JavaScriptBootstrapHandler

All Implemented Interfaces:

RequestHandler, Serializable

Direct Known Subclasses:

IndexHtmlRequestHandler
```
public class JavaScriptBootstrapHandler
extends BootstrapHandler
```
Processes a 'start' request type from the client to initialize server session and UI. It returns a JSON response with everything needed to bootstrapping flow views.
The handler is for client driven projects where `index.html` does not contain bootstrap data. Bootstraping is the responsability of the `@vaadin/flow` client that is able to ask the server side to create the vaadin session and do the boostrapping lazily.
For internal use only. May be renamed or removed in a future release.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class JavaScriptBootstrapHandler.JavaScriptBootstrapContext
Custom BootstrapContext for JavaScriptBootstrapHandler.
- Nested classes/interfaces inherited from class com.vaadin.flow.server.BootstrapHandler
  BootstrapHandler.BootstrapContext, BootstrapHandler.BootstrapPageBuilder, BootstrapHandler.BootstrapUriResolver, BootstrapHandler.PageBuilder

Field Summary
- Fields inherited from class com.vaadin.flow.server.BootstrapHandler
  SERVICE_WORKER_HEADER

Constructor Summary

Constructors
Constructor Description

JavaScriptBootstrapHandler()
Creates a new bootstrap handler with default page builder.

Method Summary

All Methods
Modifier and Type	Method	Description
`protected boolean`	`canHandleRequest(VaadinRequest request)`	Check whether a request may be handled by this handler.
`protected BootstrapHandler.BootstrapContext`	`createAndInitUI(Class<? extends UI> uiClass, VaadinRequest request, VaadinResponse response, VaadinSession session)`
`protected BootstrapHandler.BootstrapContext`	`createBootstrapContext(VaadinRequest request, VaadinResponse response, UI ui, Function<VaadinRequest,String> callback)`	Creates a new instance of `BootstrapHandler.BootstrapContext` for given `request`, `response` and `ui`.
`protected elemental.json.JsonObject`	`getInitialJson(VaadinRequest request, VaadinResponse response, VaadinSession session)`	Returns the JSON object with the application config and UIDL info that can be used in the bootstrapper to embed that info in the initial page.
`protected String`	`getRequestUrl(VaadinRequest request)`
`protected static String`	`getServiceUrl(VaadinRequest vaadinRequest)`	Gets the service URL as a URL relative to the request URI.
`protected void`	`initializeUIWithRouter(BootstrapHandler.BootstrapContext context, UI ui)`
`boolean`	`synchronizedHandleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response)`	Identical to `SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)` except the `VaadinSession` is locked before this is called and unlocked after this has completed.

Methods inherited from class com.vaadin.flow.server.BootstrapHandler
getInitialUidl, getPageBuilder, getPushScript, getUIClass, isFrameworkInternalRequest, isRequestForHtml, isVaadinStaticFileRequest, readResource, resolvePageTitle, setupErrorDialogs, setupPushConnectionFactory, setupPwa, showWebpackErrors, writeErrorCodeIfRequestLocationIsInvalid

Methods inherited from class com.vaadin.flow.server.SynchronizedRequestHandler
handleRequest

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - JavaScriptBootstrapHandler
```
public JavaScriptBootstrapHandler()
```
    Creates a new bootstrap handler with default page builder.
- Method Detail
  - canHandleRequest
```
protected boolean canHandleRequest(VaadinRequest request)
```
    Description copied from class: SynchronizedRequestHandler
    
    Check whether a request may be handled by this handler. This can be used as an optimization to avoid locking the session just to investigate some method property. The default implementation just returns true which means that all requests will be handled by calling SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) with the session locked.
    
    Overrides:
    
    canHandleRequest in class BootstrapHandler
    
    Parameters:
    
    request - the request to handle
    
    Returns:
    
    true if the request handling should continue once the session has been locked; false if there's no need to lock the session since the request would still not be handled.
  - getRequestUrl
```
protected String getRequestUrl(VaadinRequest request)
```
  - createAndInitUI
```
protected BootstrapHandler.BootstrapContext createAndInitUI(Class<? extends UI> uiClass,
                                                            VaadinRequest request,
                                                            VaadinResponse response,
                                                            VaadinSession session)
```
    Overrides:
    
    createAndInitUI in class BootstrapHandler
  - initializeUIWithRouter
```
protected void initializeUIWithRouter(BootstrapHandler.BootstrapContext context,
                                      UI ui)
```
    Overrides:
    
    initializeUIWithRouter in class BootstrapHandler
  - createBootstrapContext
```
protected BootstrapHandler.BootstrapContext createBootstrapContext(VaadinRequest request,
                                                                   VaadinResponse response,
                                                                   UI ui,
                                                                   Function<VaadinRequest,String> callback)
```
    Description copied from class: BootstrapHandler
    
    Creates a new instance of BootstrapHandler.BootstrapContext for given request, response and ui.
    
    Overrides:
    
    createBootstrapContext in class BootstrapHandler
    
    Parameters:
    
    request - the request object
    
    response - the response object
    
    ui - the UI object
    
    Returns:
    
    a new bootstrap context instance
  - synchronizedHandleRequest
```
public boolean synchronizedHandleRequest(VaadinSession session,
                                         VaadinRequest request,
                                         VaadinResponse response)
                                  throws IOException
```
    Description copied from class: SynchronizedRequestHandler
    
    Identical to SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse) except the VaadinSession is locked before this is called and unlocked after this has completed.
    
    Overrides:
    
    synchronizedHandleRequest in class BootstrapHandler
    
    Parameters:
    
    session - The session for the request
    
    request - The request to handle
    
    response - The response object to which a response can be written.
    
    Returns:
    
    true if a response has been written and no further request handlers should be called, otherwise false
    
    Throws:
    
    IOException - If an IO error occurred
    
    See Also:
    
    SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)
  - getServiceUrl
```
protected static String getServiceUrl(VaadinRequest vaadinRequest)
```
    Gets the service URL as a URL relative to the request URI.
    
    Parameters:
    
    vaadinRequest - the request
    
    Returns:
    
    the relative service URL
  - getInitialJson
```
protected elemental.json.JsonObject getInitialJson(VaadinRequest request,
                                                   VaadinResponse response,
                                                   VaadinSession session)
```
    Returns the JSON object with the application config and UIDL info that can be used in the bootstrapper to embed that info in the initial page.
    
    Parameters:
    
    request - the vaadin request.
    
    response - the response.
    
    session - the vaadin session.
    
    Returns:
    
    the initial application JSON.

com.vaadin.flow.server.communication.

Class JavaScriptBootstrapHandler

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.flow.server.BootstrapHandler

Field Summary

Fields inherited from class com.vaadin.flow.server.BootstrapHandler

Constructor Summary

Method Summary

Methods inherited from class com.vaadin.flow.server.BootstrapHandler

Methods inherited from class com.vaadin.flow.server.SynchronizedRequestHandler

Methods inherited from class java.lang.Object

Constructor Detail

JavaScriptBootstrapHandler

Method Detail

canHandleRequest

getRequestUrl

createAndInitUI

initializeUIWithRouter

createBootstrapContext

synchronizedHandleRequest

getServiceUrl

getInitialJson