Package com.vaadin.flow.server.communication

Class WebComponentProvider

java.lang.Object

com.vaadin.flow.server.SynchronizedRequestHandler

com.vaadin.flow.server.communication.WebComponentProvider

All Implemented Interfaces:

RequestHandler, Serializable

public class WebComponentProvider
extends SynchronizedRequestHandler

Request handler that supplies the script/html of the web component matching the given tag.

For internal use only. May be renamed or removed in a future release.

Since:

2.0

Author:

Vaadin Ltd.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
WebComponentProvider()

Method Summary

Modifier and Type	Method	Description
protected String	bootstrapNpm()
protected boolean	canHandleRequest(VaadinRequest request)	Check whether a request may be handled by this handler.
protected String	generateNPMResponse(String tagName, VaadinRequest request, VaadinResponse response)	Generate the npm response for the web component.
boolean	isCacheEnabled()	Whether bootstrap HTML fragment are cached based on component tag.
void	setCacheEnabled(boolean cacheEnabled)	Enable / disable bootstrap HTML fragment caching based on component tag.
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.SynchronizedRequestHandler

handleRequest

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

WebComponentProvider

public WebComponentProvider()

Method Details

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 SynchronizedRequestHandler

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.

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.

Specified by:

synchronizedHandleRequest in class SynchronizedRequestHandler

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)

isCacheEnabled

public boolean isCacheEnabled()

Whether bootstrap HTML fragment are cached based on component tag. Enabled by default.

Returns:

true iff bootstrap fragment caching is enabled

setCacheEnabled

public void setCacheEnabled(boolean cacheEnabled)

Enable / disable bootstrap HTML fragment caching based on component tag. Calling this method has the side effect of always clearing the cache.

Parameters:

cacheEnabled - whether bootstrap fragments should be cached per tag

generateNPMResponse

protected String generateNPMResponse(String tagName,
 VaadinRequest request,
 VaadinResponse response)

Generate the npm response for the web component.

Parameters:

tagName - tag name of component

request - current VaadinRequest

response - current VaadinResponse

Returns:

npm response script

bootstrapNpm

protected String bootstrapNpm()