Documentation

Class: Screen

Screen

new Screen()

Screen class is a special type of route handler that provides helper utilities that adds lifecycle and methods to provide content to each registered surface.

Extends

Members

<protected, non-null> cache :Object

Holds the cached data.
Type:
  • Object
Inherited From:
Default Value:
  • null

<protected> cacheable :boolean

Holds whether class is cacheable.
Type:
  • boolean
Inherited From:
Default Value:
  • false

<protected> id :string

Holds the screen id.
Type:
  • string

<protected, nullable> title :string

Holds the screen title. Relevant when the page title should be upadated when screen is rendered.
Type:
  • string
Default Value:
  • null

Methods

<static> isImplementedBy(object)

Parameters:
Name Type Description
object *
Returns:
Whether a given instance implements Screen.
Type
boolean

activate()

Fires when the screen is active. Allows a screen to perform any setup that requires its DOM to be visible. Lifecycle.

addCache(content)

Adds content to the cache.
Parameters:
Name Type Description
content string Content to be cached.
Inherited From:

beforeDeactivate()

Gives the Screen a chance to cancel the navigation and stop itself from being deactivated. Can be used, for example, if the screen has unsaved state. Lifecycle. Clean-up should not be preformed here, since the navigation may still be cancelled. Do clean-up in deactivate.
Returns:
If returns true, the current screen is locked and the next nagivation interrupted.
Type
boolean

beforeUpdateHistoryPath()

Gives the Screen a chance format the path before history update.
Returns:
Navigation path to use on history.
Type
string

beforeUpdateHistoryState()

Gives the Screen a chance format the state before history update.
Returns:
History state to use on history.
Type
object

clearCache()

Clears the cache.
Inherited From:

deactivate()

Allows a screen to do any cleanup necessary after it has been deactivated, for example cancelling outstanding requests or stopping timers. Lifecycle.

disposeInternal()

Dispose a screen, either after it is deactivated (in the case of a non-cacheable view) or when the App is itself disposed for whatever reason. Lifecycle.
Overrides:

evaluateScripts(surfaces)

Allows a screen to evaluate scripts before the element is made visible. Lifecycle.
Parameters:
Name Type Description
surfaces object Map of surfaces to flip keyed by surface id.
Returns:
This can return a promise, which will pause the navigation until it is resolved.
Type
CancellablePromise

evaluateStyles(surfaces)

Allows a screen to evaluate styles before the element is made visible. Lifecycle.
Parameters:
Name Type Description
surfaces object Map of surfaces to flip keyed by surface id.
Returns:
This can return a promise, which will pause the navigation until it is resolved.
Type
CancellablePromise

flip(surfaces)

Allows a screen to perform any setup immediately before the element is made visible. Lifecycle.
Parameters:
Name Type Description
surfaces object Map of surfaces to flip keyed by surface id.
Returns:
This can return a promise, which will pause the navigation until it is resolved.
Type
CancellablePromise

<protected> getCache()

Gets the cached content.
Inherited From:
Returns:
Cached content.
Type
Object

getId()

Gets the screen id.
Returns:
Type
string

getSurfaceContent(surfaceId)

Returns the content for the given surface, or null if the surface isn't used by this screen. This will be called when a screen is initially constructed or, if a screen is non-cacheable, when navigated.
Parameters:
Name Type Description
surfaceId string The id of the surface DOM element.
Returns:
This can return a string or node representing the content of the surface. If returns falsy values surface default content is restored.
Type
string | Element

getTitle()

Gets the screen title.
Returns:
Type
string

isCacheable()

Whether the class is cacheable.
Inherited From:
Returns:
Returns true when class is cacheable, false otherwise.
Type
boolean

load( [path])

Returns all contents for the surfaces. This will pass the loaded content to Screen.load with all information you need to fulfill the surfaces. Lifecycle.
Parameters:
Name Type Argument Description
path string <optional>
 The requested path.
Returns:
This can return a string representing the contents of the surfaces or a promise, which will pause the navigation until it is resolved. This is useful for loading async content.
Type
CancellablePromise

setCacheable(cacheable)

Sets whether the class is cacheable.
Parameters:
Name Type Description
cacheable boolean
Inherited From:

setId(id)

Sets the screen id.
Parameters:
Name Type Description
id string

setTitle( [title])

Sets the screen title.
Parameters:
Name Type Argument Description
title string <optional>
<nullable>

toString()

Returns:
Type
string