com.vaadin.flow.server.communication.

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

All Implemented Interfaces:

RequestHandler, Serializable
```
public class WebComponentBootstrapHandler
extends BootstrapHandler
```
Bootstrap handler for WebComponent requests.
For internal use only. May be renamed or removed in a future release.

Since:

2.0

Author:

Vaadin Ltd.

See Also:

Serialized Form

Nested Class Summary
- 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
Modifier	Constructor and Description
	`WebComponentBootstrapHandler()` Creates a new bootstrap handler with default page builder.
`protected`	`WebComponentBootstrapHandler(BootstrapHandler.PageBuilder pageBuilder)` Creates a new bootstrap handler, allowing to use custom page builder.

Method Summary

All Methods
Modifier and Type	Method and 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 String`	`getRequestUrl(VaadinRequest request)` Returns the request's base url to use in constructing and initialising ui.
`protected String`	`getServiceUrl(VaadinRequest request, VaadinResponse response)` Returns the service url needed for initialising the UI.
`protected boolean`	`handleWebComponentResyncRequest(BootstrapHandler.BootstrapContext context, VaadinRequest request, VaadinResponse response)` Handles WebComponents resynchronization request
`protected String`	`modifyPath(String basePath, String path)` Create a new address for a resource which is calculated based on the request base path (servlet path) and the original path for the Vaadin resource.
`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.
`protected void`	`writeBootstrapPage(String contentType, VaadinResponse response, org.jsoup.nodes.Element head, String serviceUrl)` Copies the `Elements` found in the given `head` elements into the head of the embedding website using JavaScript.

Methods inherited from class com.vaadin.flow.server.BootstrapHandler
getInitialUidl, getPageBuilder, getPushScript, getUIClass, initializeUIWithRouter, isFrameworkInternalRequest, 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
  - WebComponentBootstrapHandler
```
public WebComponentBootstrapHandler()
```
    Creates a new bootstrap handler with default page builder.
  - WebComponentBootstrapHandler
```
protected WebComponentBootstrapHandler(BootstrapHandler.PageBuilder pageBuilder)
```
    Creates a new bootstrap handler, allowing to use custom page builder.
    
    Parameters:
    
    pageBuilder - Page builder to use.
- 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)
```
    Returns the request's base url to use in constructing and initialising ui.
    
    Parameters:
    
    request - Request to the url for.
    
    Returns:
    
    Request's url.
  - createAndInitUI
```
protected BootstrapHandler.BootstrapContext createAndInitUI(Class<? extends UI> uiClass,
                                                            VaadinRequest request,
                                                            VaadinResponse response,
                                                            VaadinSession session)
```
    Overrides:
    
    createAndInitUI 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)
  - writeBootstrapPage
```
protected void writeBootstrapPage(String contentType,
                                  VaadinResponse response,
                                  org.jsoup.nodes.Element head,
                                  String serviceUrl)
                           throws IOException
```
    Copies the Elements found in the given head elements into the head of the embedding website using JavaScript. Drops <base> element.
    
    Parameters:
    
    contentType - Content type of the response.
    
    response - VaadinResponse into which the script is written
    
    head - head element of Vaadin Bootstrap page. The child elements are copied into the embedding page's head using JavaScript.
    
    serviceUrl - base path to use for the head elements' URLs
    
    Throws:
    
    IOException - if writing fails
  - modifyPath
```
protected String modifyPath(String basePath,
                            String path)
```
    Create a new address for a resource which is calculated based on the request base path (servlet path) and the original path for the Vaadin resource.
    If the resource is targeted to context root with VAADIN prefix, the path part before the VAADIN is chopped of since that has been calculated to be relative to our context and would target context root instead of the serving servlet.
    
    Parameters:
    
    basePath - full servlet path, received as part of the bootstrap request. Needs to be the client-side path used, to get around proxies.
    
    path - original resource path
    
    Returns:
    
    new resource path, relative to basePath
  - getServiceUrl
```
protected String getServiceUrl(VaadinRequest request,
                               VaadinResponse response)
```
    Returns the service url needed for initialising the UI.
    
    Parameters:
    
    request - the request object
    
    response - the response object
    
    Returns:
    
    Service url for the given request.
  - handleWebComponentResyncRequest
```
protected boolean handleWebComponentResyncRequest(BootstrapHandler.BootstrapContext context,
                                                  VaadinRequest request,
                                                  VaadinResponse response)
```
    Handles WebComponents resynchronization request
    
    Parameters:
    
    context - the bootstrap context object
    
    request - the request object
    
    response - the response object
    
    Returns:
    
    true if request has been handled, false otherwise

com.vaadin.flow.server.communication.

Class WebComponentBootstrapHandler

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

WebComponentBootstrapHandler

WebComponentBootstrapHandler

Method Detail

canHandleRequest

getRequestUrl

createAndInitUI

createBootstrapContext

synchronizedHandleRequest

writeBootstrapPage

modifyPath

getServiceUrl

handleWebComponentResyncRequest