com.vaadin.flow.component.page

Class Page

java.lang.Object

com.vaadin.flow.component.page.Page

All Implemented Interfaces:

Serializable

public class Page
extends Object
implements Serializable

Represents the web page open in the browser, containing the UI it is connected to.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Page.ExecutionCanceler Deprecated. superseded by PendingJavaScriptResult
static interface	Page.ExtendedClientDetailsReceiver Callback for receiving extended client-side details.

Constructor Summary

Constructors

Constructor and Description
Page(UI ui) Creates a page instance for the given UI.

Method Summary

Modifier and Type	Method and Description
Registration	addBrowserWindowResizeListener(BrowserWindowResizeListener resizeListener) Adds a new BrowserWindowResizeListener to this UI.
void	addDynamicImport(String expression) Adds a dynamic import using a JavaScript expression which is supposed to return a JavaScript Promise.
void	addHtmlImport(String url) In compatibility mode (or Flow 1.x), adds the given HTML import to the page and ensures that it is loaded successfully.
void	addHtmlImport(String url, LoadMode loadMode) In compatibility mode (or Flow 1.x), adds the given HTML import to the page and ensures that it is loaded successfully.
void	addJavaScript(String url) Adds the given JavaScript to the page and ensures that it is loaded successfully.
void	addJavaScript(String url, LoadMode loadMode) Adds the given JavaScript to the page and ensures that it is loaded successfully.
void	addJsModule(String url) Adds the given external JavaScript module to the page and ensures that it is loaded successfully.
void	addJsModule(String url, LoadMode loadMode) Deprecated. LoadMode is not functional with external JavaScript modules, as those are loaded as deferred due to type=module in scrip tag. Use addJsModule(String) instead.
void	addStyleSheet(String url) Adds the given style sheet to the page and ensures that it is loaded successfully.
void	addStyleSheet(String url, LoadMode loadMode) Adds the given style sheet to the page and ensures that it is loaded successfully.
Page.ExecutionCanceler	executeJavaScript(String expression, Serializable... parameters) Deprecated. Use executeJs(String,Serializable...) instead since it also allows getting return value back.
PendingJavaScriptResult	executeJs(String expression, Serializable... parameters) Asynchronously runs the given JavaScript expression in the browser.
void	fetchCurrentURL(SerializableConsumer<URL> callback) Retrieves the current url from the browser.
History	getHistory() Gets a representation of window.history for this page.
void	open(String url) Opens the given url in a new tab.
void	open(String url, String windowName) Opens the given URL in a window with the given name.
void	reload() Reloads the page in the browser.
void	retrieveExtendedClientDetails(Page.ExtendedClientDetailsReceiver receiver) Obtain extended client side details, such as time screen and time zone information, via callback.
void	setLocation(String uri) Navigates this page to the given URI.
void	setLocation(URI uri) Navigates this page to the given URI.
void	setTitle(String title) Sets the page title.

Methods inherited from class java.lang.Object

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

Constructor Detail

Page

public Page(UI ui)

Creates a page instance for the given UI.

Parameters:

ui - the UI that this page instance is connected to

Method Detail

setTitle

public void setTitle(String title)

Sets the page title. The title is displayed by the browser e.g. as the title of the browser window or tab.

To clear the page title, use an empty string.

Parameters:

title - the page title to set, not null

addStyleSheet

public void addStyleSheet(String url)

Adds the given style sheet to the page and ensures that it is loaded successfully.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

For component related style sheet dependencies, you should use the @StyleSheet annotation.

Is is guaranteed that style sheet will be loaded before the first page load. For more options, refer to addStyleSheet(String, LoadMode)

Parameters:

url - the URL to load the style sheet from, not null

addStyleSheet

public void addStyleSheet(String url,
                          LoadMode loadMode)

Adds the given style sheet to the page and ensures that it is loaded successfully.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

For component related style sheet dependencies, you should use the @StyleSheet annotation.

Parameters:

url - the URL to load the style sheet from, not null

loadMode - determines dependency load mode, refer to LoadMode for details

addJavaScript

public void addJavaScript(String url)

Adds the given JavaScript to the page and ensures that it is loaded successfully.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

For component related JavaScript dependencies, you should use the @JavaScript annotation.

Is is guaranteed that script will be loaded before the first page load. For more options, refer to addJavaScript(String, LoadMode)

Parameters:

url - the URL to load the JavaScript from, not null

addJavaScript

public void addJavaScript(String url,
                          LoadMode loadMode)

Adds the given JavaScript to the page and ensures that it is loaded successfully.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

For component related JavaScript dependencies, you should use the @JavaScript annotation.

Parameters:

url - the URL to load the JavaScript from, not null

loadMode - determines dependency load mode, refer to LoadMode for details

addJsModule

public void addJsModule(String url)

Adds the given external JavaScript module to the page and ensures that it is loaded successfully.

If the JavaScript modules do not need to be added dynamically, you should use the @JsModule annotation instead.

Parameters:

url - the URL to load the JavaScript module from, not null

addJsModule

@Deprecated
public void addJsModule(String url,
                                    LoadMode loadMode)

Deprecated. LoadMode is not functional with external JavaScript modules, as those are loaded as deferred due to type=module in scrip tag. Use addJsModule(String) instead.

Adds the given external JavaScript module to the page and ensures that it is loaded successfully.

If the JavaScript modules do not need to be added dynamically, you should use the @JsModule annotation instead.

Parameters:

url - the URL to load the JavaScript module from, not null

loadMode - this argument is ignored and the loadMode will always be LoadMode.EAGER since LoadMode doesn't work with Dependency.Type.JS_MODULE. See Deprecated section for more details.

addHtmlImport

public void addHtmlImport(String url)

In compatibility mode (or Flow 1.x), adds the given HTML import to the page and ensures that it is loaded successfully. In normal mode (Flow 2.x with npm support), throws an UnsupportedOperationException.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

Is is guaranteed that html import will be loaded before the first page load. For more options, refer to addHtmlImport(String, LoadMode)

Parameters:

url - the URL to load the HTML import from, not null

Throws:

UnsupportedOperationException - if called outside of compatibility mode.

addHtmlImport

public void addHtmlImport(String url,
                          LoadMode loadMode)

In compatibility mode (or Flow 1.x), adds the given HTML import to the page and ensures that it is loaded successfully. In normal mode (Flow 2.x with npm support), throws an UnsupportedOperationException.

Relative URLs are interpreted as relative to the configured frontend directory location. You can prefix the URL with context:// to make it relative to the context path or use an absolute URL to refer to files outside the frontend directory.

Parameters:

url - the URL to load the HTML import from, not null

loadMode - determines dependency load mode, refer to LoadMode for details

Throws:

UnsupportedOperationException - if called outside of compatibility mode.

addDynamicImport

public void addDynamicImport(String expression)

Adds a dynamic import using a JavaScript expression which is supposed to return a JavaScript Promise.

No change will be applied on the client side until resulting Promise of the expression is completed. It behaves like other dependencies (addJavaScript(String), addJsModule(String), etc.)

Parameters:

expression - the JavaScript expression which return a Promise

See Also:

addHtmlImport(String)

executeJavaScript

@Deprecated
public Page.ExecutionCanceler executeJavaScript(String expression,
                                                            Serializable... parameters)

Deprecated. Use executeJs(String,Serializable...) instead since it also allows getting return value back.

Asynchronously runs the given JavaScript expression in the browser. The given parameters will be available to the expression as variables named $0, $1, and so on. Supported parameter types are:

• String
• Integer
• Double
• Boolean
• JsonValue
• Element (will be sent as null if the server-side element instance is not attached when the invocation is sent to the client)

Note that the parameter variables can only be used in contexts where a JavaScript variable can be used. You should for instance do 'prefix' + $0 instead of 'prefix$0' and value[$0] instead of value.$0 since JavaScript variables aren't evaluated inside strings or property names.

Parameters:

expression - the JavaScript expression to invoke

parameters - parameters to pass to the expression

Returns:

a callback for canceling the execution if not yet sent to browser

executeJs

public PendingJavaScriptResult executeJs(String expression,
                                         Serializable... parameters)

Asynchronously runs the given JavaScript expression in the browser.

The returned PendingJavaScriptResult can be used to retrieve any return value from the JavaScript expression. If no return value handler is registered, the return value will be ignored.

The given parameters will be available to the expression as variables named $0, $1, and so on. Supported parameter types are:

• String
• Integer
• Double
• Boolean
• JsonValue
• Element (will be sent as null if the server-side element instance is not attached when the invocation is sent to the client)

Note that the parameter variables can only be used in contexts where a JavaScript variable can be used. You should for instance do 'prefix' + $0 instead of 'prefix$0' and value[$0] instead of value.$0 since JavaScript variables aren't evaluated inside strings or property names.

Parameters:

expression - the JavaScript expression to invoke

parameters - parameters to pass to the expression

Returns:

a pending result that can be used to get a value returned from the expression

getHistory

public History getHistory()

Gets a representation of window.history for this page.

Returns:

the history representation

reload

public void reload()

Reloads the page in the browser.

addBrowserWindowResizeListener

public Registration addBrowserWindowResizeListener(BrowserWindowResizeListener resizeListener)

Adds a new BrowserWindowResizeListener to this UI. The listener will be notified whenever the browser window within which this UI resides is resized.

Parameters:

resizeListener - the listener to add, not null

Returns:

a registration object for removing the listener

See Also:

BrowserWindowResizeListener.browserWindowResized(BrowserWindowResizeEvent), Registration

open

public void open(String url)

Opens the given url in a new tab.

Parameters:

url - the URL to open.

open

public void open(String url,
                 String windowName)

Opens the given URL in a window with the given name.

The supplied windowName is used as the target name in a window.open call in the client. This means that special values such as "_blank", "_self", "_top", "_parent" have special meaning. An empty or null window name is also a special case.

"", null and "_self" as windowName all causes the URL to be opened in the current window, replacing any old contents. For downloadable content you should avoid "_self" as "_self" causes the client to skip rendering of any other changes as it considers them irrelevant (the page will be replaced by the response from the URL). This can speed up the opening of a URL, but it might also put the client side into an inconsistent state if the window content is not completely replaced e.g., if the URL is downloaded instead of displayed in the browser.

"_blank" as windowName causes the URL to always be opened in a new window or tab (depends on the browser and browser settings).

"_top" and "_parent" as windowName works as specified by the HTML standard.

Any other windowName will open the URL in a window with that name, either by opening a new window/tab in the browser or by replacing the contents of an existing window with that name.

Parameters:

url - the URL to open.

windowName - the name of the window.

setLocation

public void setLocation(String uri)

Navigates this page to the given URI. The contents of this page in the browser is replaced with whatever is returned for the given URI.

Parameters:

uri - the URI to show

setLocation

public void setLocation(URI uri)

Navigates this page to the given URI. The contents of this page in the browser is replaced with whatever is returned for the given URI.

Parameters:

uri - the URI to show

retrieveExtendedClientDetails

public void retrieveExtendedClientDetails(Page.ExtendedClientDetailsReceiver receiver)

Obtain extended client side details, such as time screen and time zone information, via callback. If already obtained, the callback is called directly. Otherwise, a client-side roundtrip will be carried out.

Parameters:

receiver - the callback to which the details are provided

fetchCurrentURL

public void fetchCurrentURL(SerializableConsumer<URL> callback)

Retrieves the current url from the browser. The URL is fetched from the browser in another request asynchronously and passed to the callback. The URL is the full URL that the user sees in the browser (including hash #) and works even when client side routing is used or there is a reverse proxy between the client and the server.

In case you need more control over the execution you can use executeJs(String, Serializable...) by passing return window.location.href.

NOTE: the URL is not escaped, use URL.toURI() to escape it.

Parameters:

callback - to be notified when the url is resolved.