Page (zk 8.5.1 API)

All Superinterfaces:

ClassResolver, IdSpace, Scope

All Known Implementing Classes:

AbstractPage, PageImpl, VolatilePage
```
public interface Page
extends IdSpace, Scope, ClassResolver
```
A page. A desktop consists of a set of pages.
When a ZK request is asking to render a new page, a new page is created and components that are created during this request all belong to this page.
If a ZK request is asking an update, it must have at lease one UUID of a component (Component.getUuid(). From this UUID, we know which page it belongs and activate it to process the update.
By activation, the system guarantees no concurrent access to pages and components (so you don't need use synchronized for them).
Desktop

In portal and some environments, a client request (e.g., ServletRequest) might consists of several ZK requests (AuRequest). While each ZK request might ask to create an independent page, all these pages are grouped as a desktop, such that they are activated and removed at the same time. Moreover, pages in the same desktop could communicate to each other (see Inter-page communication).
A session, Session, might have multiple desktops of pages, Page, while a page belongs to exactly one session. A page, Page, might have many components, Component, while a component belongs to exactly one page.
All components of the same desktop of pages are removed at the same time if a page become 'obsolete'.
During each execution (${link Execution}), exactly one desktop of pages are locked (a.k.a., activated). Though an execution serves a client request (e.g., ServletRequest), a client request might consist of multiple ZK request (AuRequest). Each ZK request might target to a different page (of the same desktop).
Inter-page Communication

To do inter-page communication, you could do:
1. Invoke methods of components from another page directly.
2. Use Execution.postEvent(org.zkoss.zk.ui.event.Event) to post events to components from another page.
They are the same as handling components from the same page. However, invoking method directly for components from another page has one restriction:
It cannot create component.
Author:

tomyeh

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`APPLICATION_SCOPE` Used with `getAttribute(String, int)` and related to denote custom attributes shared by the whole application.
`static int`	`DESKTOP_SCOPE` Used with `getAttribute(String, int)` and related to denote custom attributes shared by the same desktop.
`static int`	`PAGE_SCOPE` Used with `getAttribute(String, int)` and related to denote custom attributes shared by the same page.
`static int`	`REQUEST_SCOPE` Used with `getAttribute(String, int)` and related to denote custom attributes shared by the same request.
`static int`	`SESSION_SCOPE` Used with `getAttribute(String, int)` and related to denote custom attributes shared by the same session.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`boolean`	`addClassResolver(ClassResolver resolver)` Adds a class resolver to this page.
`boolean`	`addEventListener(java.lang.String evtnm, EventListener<? extends Event> listener)` Adds an event listener to specified event for all components in this page.
`boolean`	`addFunctionMapper(FunctionMapper mapper)` Adds the function mapper in addition to the current one.
`void`	`addTemplate(java.lang.String name, Template template)` Adds page scope template
`boolean`	`addVariableResolver(VariableResolver resolver)` Adds a variable resolver that will be used to resolve a variable by `getXelVariable(java.lang.String)`.
`java.lang.Object`	`getAttribute(java.lang.String name)` Returns the value of the specified attribute associated with this page.
`java.lang.Object`	`getAttribute(java.lang.String name, int scope)` Returns the value of the specified custom attribute in the specified scope.
`java.lang.Object`	`getAttributeOrFellow(java.lang.String name, boolean recurse)` Returns the custom attribute associated with this page, or the fellow of this page; or null if no found.
`java.util.Map<java.lang.String,java.lang.Object>`	`getAttributes()` Returns all custom attributes associated with this page.
`java.util.Map<java.lang.String,java.lang.Object>`	`getAttributes(int scope)` Returns all custom attributes of the specified scope.
`ComponentDefinition`	`getComponentDefinition(java.lang.Class<? extends Component> cls, boolean recurse)` Returns the component definition of the specified class, or null if not found.
`ComponentDefinition`	`getComponentDefinition(java.lang.String name, boolean recurse)` Returns the component definition of the specified name, or null if not found.
`ComponentDefinitionMap`	`getComponentDefinitionMap()` Returns the map of component definitions (never null).
`Desktop`	`getDesktop()` Returns the desktop that this page belongs to.
`java.lang.Iterable<EventListener<? extends Event>>`	`getEventListeners(java.lang.String evtnm)` Returns an iterable collection of the event listeners for the given event.
`java.lang.Class<? extends ExpressionFactory>`	`getExpressionFactoryClass()` Returns the implementation of the expression factory that is used by this page, or null if `Configuration.getExpressionFactoryClass()` is used.
`Component`	`getFirstRoot()` Returns the first root component.
`FunctionMapper`	`getFunctionMapper()` Returns the function mapper for resolving XEL functions, or null if not available.
`java.lang.String`	`getId()` Returns ID which is unique in the request (never null).
`Interpreter`	`getInterpreter(java.lang.String zslang)` Returns the interpreter of the specified scripting language.
`LanguageDefinition`	`getLanguageDefinition()` Returns the language definition that this page belongs to (never null).
`Component`	`getLastRoot()` Returns the last root component.
`java.util.Iterator<EventListener<? extends Event>>`	`getListenerIterator(java.lang.String evtnm)` Deprecated. As of release 6.0, replaced with `getEventListeners(java.lang.String)`. Returns an iterator for iterating the event listeners for the given event.
`java.util.Collection<Interpreter>`	`getLoadedInterpreters()` Returns all loaded interpreters.
`java.lang.String`	`getRequestPath()` Returns the request path of this page, or "" if not available.
`java.util.Collection<Component>`	`getRoots()` Returns a readonly list of the root components.
`java.lang.String`	`getStyle()` Returns the CSS style of this page, or empty if not specified.
`Template`	`getTemplate(java.lang.String name)` Gets page scope template by name
`java.lang.String`	`getTitle()` Returns the title of the desktop this page belongs to (and evaluate it if it contains an expression).
`java.lang.String`	`getUuid()` Returns UUID (universal unique ID) which is unique in the whole session.
`java.lang.String`	`getViewport()` Return the meta viewport of this page, or "auto" if not specified.
`java.lang.Object`	`getXelVariable(java.lang.String name)` Returns a variable that is visible to XEL expressions.
`java.lang.Object`	`getXelVariable(XelContext ctx, java.lang.Object base, java.lang.Object name, boolean ignoreExec)` Returns a variable that is visible to XEL expressions.
`java.lang.Class<?>`	`getZScriptClass(java.lang.String clsnm)` Returns the class of the specified name by searching the classes defined in the loaded interpreters (`getLoadedInterpreters()`).
`Function`	`getZScriptFunction(Component comp, java.lang.String name, java.lang.Class[] argTypes)` Returns the function of the specified name by searching the logical scope of the specified component in all the loaded interpreters.
`Function`	`getZScriptFunction(java.lang.String name, java.lang.Class[] argTypes)` Returns the function of the specified name by searching the loaded interpreters.
`java.lang.String`	`getZScriptLanguage()` Returns the default scripting language which is assumed when a zscript element doesn't specify any language.
`java.lang.Object`	`getZScriptVariable(Component comp, java.lang.String name)` Returns the value of the variable of the specified name by searching the logical scope of the specified component in all the loaded interpreters, if any.
`java.lang.Object`	`getZScriptVariable(java.lang.String name)` Returns the value of the variable of the specified name by searching the loaded interpreters, if any.
`boolean`	`hasAttribute(java.lang.String name)` Returns if an attribute exists.
`boolean`	`hasAttribute(java.lang.String name, int scope)` Returns if an attribute exists.
`boolean`	`hasAttributeOrFellow(java.lang.String name, boolean recurse)` Returns if a custom attribute is associated with this page, or a fellow of this page.
`boolean`	`hasFunctionMapper(FunctionMapper mapper)` Returns if the specified function mapper has been registered
`boolean`	`hasVariableResolver(VariableResolver resolver)` Returns if the specified variable resolver has been registered
`void`	`interpret(java.lang.String zslang, java.lang.String script, Scope scope)` Interprets a script in the specified scripting language in the context of the specified scope.
`void`	`invalidate()` Invalidates this page to cause all components to redraw.
`boolean`	`isAlive()` Returns whether the desktop is still alive.
`boolean`	`isComplete()` Returns if this page is a complete page.
`boolean`	`isListenerAvailable(java.lang.String evtnm)` Returns whether the event listener is available.
`java.lang.Object`	`removeAttribute(java.lang.String name)` Removes the specified attribute custom associated with the page.
`java.lang.Object`	`removeAttribute(java.lang.String name, int scope)` Removes the specified custom attribute in the specified scope.
`void`	`removeComponents()` Removes all components in this page.
`boolean`	`removeEventListener(java.lang.String evtnm, EventListener<? extends Event> listener)` Removes an event listener.
`boolean`	`removeFunctionMapper(FunctionMapper mapper)` Removes a function mapper that was added by `addFunctionMapper(org.zkoss.xel.FunctionMapper)`.
`void`	`removeTemplate(java.lang.String name)` Removes page scope template
`boolean`	`removeVariableResolver(VariableResolver resolver)` Removes a variable resolver that was added by `addVariableResolver(org.zkoss.xel.VariableResolver)`.
`java.lang.Class<?>`	`resolveClass(java.lang.String clsnm)` Resolves the class of the specified name.
`java.lang.Object`	`setAttribute(java.lang.String name, java.lang.Object value)` Sets the value of the specified custom attribute associated with this page.
`java.lang.Object`	`setAttribute(java.lang.String name, java.lang.Object value, int scope)` Sets the value of the specified custom attribute in the specified scope.
`void`	`setComplete(boolean complete)` Sets if the page is a complete page.
`void`	`setExpressionFactoryClass(java.lang.Class<? extends ExpressionFactory> expfcls)` Sets the implementation of the expression factory that is used by this page.
`void`	`setId(java.lang.String id)` Sets the identifier of this page.
`void`	`setStyle(java.lang.String style)` Sets the CSS style of this page.
`void`	`setTitle(java.lang.String title)` Sets the title of the desktop this page belongs to (it might contain an expression).
`void`	`setViewport(java.lang.String viewport)` Sets the viewport of this page.
`void`	`setZScriptLanguage(java.lang.String zslang)` Sets the default scripting language which will be assumed if a zscript element doesn't specify any language.

Methods inherited from interface org.zkoss.zk.ui.IdSpace
getFellow, getFellow, getFellowIfAny, getFellowIfAny, getFellows, hasFellow, hasFellow

Methods inherited from interface org.zkoss.zk.ui.ext.Scope
addScopeListener, getAttribute, hasAttribute, removeAttribute, removeScopeListener, setAttribute

- Field Detail
  - PAGE_SCOPE
```
static final int PAGE_SCOPE
```
    Used with getAttribute(String, int) and related to denote custom attributes shared by the same page.
    It is also known as the page attributes.
    It is the same as getAttributes(int).
    
    See Also:
    
    Constant Field Values
  - DESKTOP_SCOPE
```
static final int DESKTOP_SCOPE
```
    Used with getAttribute(String, int) and related to denote custom attributes shared by the same desktop.
    It is also known as the desktop attributes.
    It is the same as Desktop.getAttributes().
    
    See Also:
    
    Constant Field Values
  - SESSION_SCOPE
```
static final int SESSION_SCOPE
```
    Used with getAttribute(String, int) and related to denote custom attributes shared by the same session.
    It is also known as the session attributes.
    It is the same as Session.getAttributes().
    
    See Also:
    
    Constant Field Values
  - APPLICATION_SCOPE
```
static final int APPLICATION_SCOPE
```
    Used with getAttribute(String, int) and related to denote custom attributes shared by the whole application.
    It is also known as the application attributes.
    It is the same as WebApp.getAttributes().
    
    See Also:
    
    Constant Field Values
  - REQUEST_SCOPE
```
static final int REQUEST_SCOPE
```
    Used with getAttribute(String, int) and related to denote custom attributes shared by the same request.
    It is also known as the request attributes, or execution attributes.
    It is the same as Execution.getAttributes().
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getId
```
java.lang.String getId()
```
    Returns ID which is unique in the request (never null).
    Note: it returns null when Initiator.doInit(org.zkoss.zk.ui.Page, java.util.Map<java.lang.String, java.lang.Object>) is called.
  - setId
```
void setId(java.lang.String id)
```
    Sets the identifier of this page.
    Note: you can change the page's ID only in Initiator.doInit(org.zkoss.zk.ui.Page, java.util.Map<java.lang.String, java.lang.Object>) or ExecutionInit.init(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Execution). Once the page is initialized (by PageCtrl.init(org.zkoss.zk.ui.sys.PageConfig)), calling this method will cause an exception.
    
    Throws:
    
    UiException - if the page is initialized, i.e., PageCtrl.init(org.zkoss.zk.ui.sys.PageConfig) is called.
  - getUuid
```
java.lang.String getUuid()
```
    Returns UUID (universal unique ID) which is unique in the whole session. The UUID is generated automatically and immutable.
    It is mainly used for communication between client and server and you rarely need to access it.
  - getTitle
```
java.lang.String getTitle()
```
    Returns the title of the desktop this page belongs to (and evaluate it if it contains an expression).
    Default: "".
  - setTitle
```
void setTitle(java.lang.String title)
```
    Sets the title of the desktop this page belongs to (it might contain an expression).
  - getStyle
```
java.lang.String getStyle()
```
    Returns the CSS style of this page, or empty if not specified.
  - setStyle
```
void setStyle(java.lang.String style)
```
    Sets the CSS style of this page.
    Note: Unlike setTitle(java.lang.String), you can change the style only in the lifecycle of the loading page.
  - getViewport
```
java.lang.String getViewport()
```
    Return the meta viewport of this page, or "auto" if not specified.
    Default: "auto".
    
    Since:
    
    6.5.0
  - setViewport
```
void setViewport(java.lang.String viewport)
```
    Sets the viewport of this page.
    
    Since:
    
    6.5.0
  - getRequestPath
```
java.lang.String getRequestPath()
```
    Returns the request path of this page, or "" if not available.
    It is the same as the servlet path (javax.servlet.http.HttpServletRequest's getServletPath), if ZK is running at a servlet container.
    Note: Desktop.getRequestPath() returns the request path that causes the desktop to create. And, there might be multiple pages in the same desktop.
    
    See Also:
    
    Execution.getContextPath(), Desktop.getRequestPath()
  - isAlive
```
boolean isAlive()
```
    Returns whether the desktop is still alive. It returns false once it is destroyed.
    
    Since:
    
    5.0.3
    
    See Also:
    
    PageCtrl.destroy()
  - getDesktop
```
Desktop getDesktop()
```
    Returns the desktop that this page belongs to.
    Note: it returns null when Initiator.doInit(org.zkoss.zk.ui.Page, java.util.Map<java.lang.String, java.lang.Object>) is called.
  - getRoots
```
java.util.Collection<Component> getRoots()
```
    Returns a readonly list of the root components.
  - getFirstRoot
```
Component getFirstRoot()
```
    Returns the first root component.
    
    Since:
    
    3.5.2
  - getLastRoot
```
Component getLastRoot()
```
    Returns the last root component.
    
    Since:
    
    3.5.2
  - getAttributes
```
java.util.Map<java.lang.String,java.lang.Object> getAttributes(int scope)
```
    Returns all custom attributes of the specified scope. You could reference them directly, or by use of componentScope, spaceScope, pageScope, requestScope and desktopScope in zscript and EL.
    If scope is PAGE_SCOPE, it means custom attributes shared by components from the same page as this one's.
    If scope is DESKTOP_SCOPE, it means custom attributes shared by components from the same desktops as this one's.
    
    Parameters:
    
    scope - one of APPLICATION_SCOPE, SESSION_SCOPE, PAGE_SCOPE, REQUEST_SCOPE or DESKTOP_SCOPE.
  - getAttributes
```
java.util.Map<java.lang.String,java.lang.Object> getAttributes()
```
    Returns all custom attributes associated with this page.
    
    Specified by:
    
    getAttributes in interface Scope
  - getAttribute
```
java.lang.Object getAttribute(java.lang.String name,
                              int scope)
```
    Returns the value of the specified custom attribute in the specified scope.
    If scope is PAGE_SCOPE, it means custom attributes shared by components from the same page as this one's.
    If scope is DESKTOP_SCOPE, it means custom attributes shared by components from the same desktops as this one's.
    
    Parameters:
    
    scope - one of APPLICATION_SCOPE, SESSION_SCOPE, PAGE_SCOPE, REQUEST_SCOPE or DESKTOP_SCOPE.
  - getAttribute
```
java.lang.Object getAttribute(java.lang.String name)
```
    Returns the value of the specified attribute associated with this page.
    
    Specified by:
    
    getAttribute in interface Scope
  - hasAttribute
```
boolean hasAttribute(java.lang.String name,
                     int scope)
```
    Returns if an attribute exists.
    Notice that null is a valid value, so you need this method to really know if an attribute is defined.
    
    Since:
    
    5.0.0
  - hasAttribute
```
boolean hasAttribute(java.lang.String name)
```
    Returns if an attribute exists.
    Notice that null is a valid value, so you need this method to really know if an attribute is defined.
    
    Specified by:
    
    hasAttribute in interface Scope
    
    Since:
    
    5.0.0
  - setAttribute
```
java.lang.Object setAttribute(java.lang.String name,
                              java.lang.Object value,
                              int scope)
```
    Sets the value of the specified custom attribute in the specified scope.
    If scope is PAGE_SCOPE, it means custom attributes shared by components from the same page as this one's.
    If scope is DESKTOP_SCOPE, it means custom attributes shared by components from the same desktops as this one's.
    
    Parameters:
    
    scope - one of APPLICATION_SCOPE, SESSION_SCOPE, PAGE_SCOPE, REQUEST_SCOPE or DESKTOP_SCOPE.
  - setAttribute
```
java.lang.Object setAttribute(java.lang.String name,
                              java.lang.Object value)
```
    Sets the value of the specified custom attribute associated with this page.
    
    Specified by:
    
    setAttribute in interface Scope
    
    Parameters:
    
    value - the value.
    
    Returns:
    
    the previous value associated with the attribute, if any
  - removeAttribute
```
java.lang.Object removeAttribute(java.lang.String name,
                                 int scope)
```
    Removes the specified custom attribute in the specified scope.
    If scope is PAGE_SCOPE, it means custom attributes shared by components from the same page as this one's.
    If scope is DESKTOP_SCOPE, it means custom attributes shared by components from the same desktops as this one's.
    
    Parameters:
    
    scope - one of APPLICATION_SCOPE, SESSION_SCOPE, PAGE_SCOPE, REQUEST_SCOPE or DESKTOP_SCOPE.
  - removeAttribute
```
java.lang.Object removeAttribute(java.lang.String name)
```
    Removes the specified attribute custom associated with the page.
    
    Specified by:
    
    removeAttribute in interface Scope
    
    Returns:
    
    the previous value associated with the attribute, if any,
  - getAttributeOrFellow
```
java.lang.Object getAttributeOrFellow(java.lang.String name,
                                      boolean recurse)
```
    Returns the custom attribute associated with this page, or the fellow of this page; or null if no found.
    Notice that this method will NOT check for any variable defined in the variable resolver (addVariableResolver(org.zkoss.xel.VariableResolver)). You have to invoke getXelVariable(XelContext,Object,Object,boolean) or getXelVariable(String) manually.
    
    Parameters:
    
    recurse - whether to look up the desktop/session for the existence of the attribute.
    
    Since:
    
    5.0.0
  - hasAttributeOrFellow
```
boolean hasAttributeOrFellow(java.lang.String name,
                             boolean recurse)
```
    Returns if a custom attribute is associated with this page, or a fellow of this page.
    Notice that this method will NOT check for any variable defined in the variable resolver (addVariableResolver(org.zkoss.xel.VariableResolver)). You have to invoke getXelVariable(XelContext,Object,Object,boolean) or getXelVariable(String) manually.
    
    Parameters:
    
    recurse - whether to look up the desktop/session for the existence of the attribute.
    
    Since:
    
    5.0.0
  - resolveClass
```
java.lang.Class<?> resolveClass(java.lang.String clsnm)
                         throws java.lang.ClassNotFoundException
```
    Resolves the class of the specified name. It first looks at ClassResolver (registered with addClassResolver(org.zkoss.lang.ClassResolver)). If not found, it looks at the current thread's class loader. And then, it looks for classes defined in any loaded interpreters (getLoadedInterpreters()).
    
    Specified by:
    
    resolveClass in interface ClassResolver
    
    Parameters:
    
    clsnm - the class name. It does not have to be a fully qualified name (i.e., it could have no package name), if the class is imported by use of the import directive (such as <?import class="com.foo.*"?>).
    
    Throws:
    
    java.lang.ClassNotFoundException - if the class is not found.
    
    Since:
    
    3.0.1
  - addClassResolver
```
boolean addClassResolver(ClassResolver resolver)
```
    Adds a class resolver to this page.
    
    Parameters:
    
    resolver - the class resolver to be added. Currently it supports only ImportedClassResolver.
    
    Since:
    
    6.0.0
    
    See Also:
    
    resolveClass(java.lang.String)
  - getZScriptClass
```
java.lang.Class<?> getZScriptClass(java.lang.String clsnm)
```
    Returns the class of the specified name by searching the classes defined in the loaded interpreters (getLoadedInterpreters()).
    Note that: since ZK 6, this method will not search the current thread's class loader. In other words, you'd like to look for a class from a given page, use resolveClass(java.lang.String) instead.
    Also notice that it won't throw an exception if not found. Rather, it returns null.
    
    Parameters:
    
    clsnm - the fully qualified class name. Unlike resolveClass(java.lang.String), this method does not support the imported class (by addClassResolver(org.zkoss.lang.ClassResolver)).
    
    Returns:
    
    the class, or null if not found
    
    See Also:
    
    resolveClass(java.lang.String), getLoadedInterpreters()
  - getZScriptFunction
```
Function getZScriptFunction(java.lang.String name,
                            java.lang.Class[] argTypes)
```
    Returns the function of the specified name by searching the loaded interpreters.
    
    Returns:
    
    the method, or null if not found
    
    Since:
    
    3.0.0
    
    See Also:
    
    getLoadedInterpreters()
  - getZScriptFunction
```
Function getZScriptFunction(Component comp,
                            java.lang.String name,
                            java.lang.Class[] argTypes)
```
    Returns the function of the specified name by searching the logical scope of the specified component in all the loaded interpreters.
    
    Parameters:
    
    comp - the component to start the search. If null, this method searches only the page's attributes. In other words, if comp is null, this method is the same as getZScriptFunction(String, Class[]).
    
    Since:
    
    3.0.0
  - getZScriptVariable
```
java.lang.Object getZScriptVariable(java.lang.String name)
```
    Returns the value of the variable of the specified name by searching the loaded interpreters, if any.
    
    Returns:
    
    the value of the variable, or null if not found
    
    See Also:
    
    getLoadedInterpreters()
  - getZScriptVariable
```
java.lang.Object getZScriptVariable(Component comp,
                                    java.lang.String name)
```
    Returns the value of the variable of the specified name by searching the logical scope of the specified component in all the loaded interpreters, if any.
    
    Parameters:
    
    comp - the component as the context to look for the variable defined in an interpreter. If null, the context is assumed to be this page.
    
    Since:
    
    3.0.0
  - getXelVariable
```
java.lang.Object getXelVariable(java.lang.String name)
```
    Returns a variable that is visible to XEL expressions. It is a shortcut of getXelVariable(null, null, name, false).
    This method is mainly used to access special variable, such as request parameters (if this page is requested by HTTP).
    
    Since:
    
    3.0.0
    
    See Also:
    
    getXelVariable(XelContext, Object, Object, boolean)
  - getXelVariable
```
java.lang.Object getXelVariable(XelContext ctx,
                                java.lang.Object base,
                                java.lang.Object name,
                                boolean ignoreExec)
```
    Returns a variable that is visible to XEL expressions.
    Unlike getXelVariable(String), this method can utilize VariableResolverX if you'd like to retrieve a property of another object.
    
    Parameters:
    
    ctx - the XEL context
    
    base - the base object. If null, it looks for a top-level variable. If not null, it looks for a member of the base object (such as getter).
    
    name - the property to retrieve.
    
    ignoreExec - whether to ignore the current execution (Execution.getVariableResolver(). If true, it invokes only the variable resolvers define in this page (addVariableResolver(org.zkoss.xel.VariableResolver)). If false, it will first check the execution, so the implicit objects such as page and desktop will be resolved.
    
    Since:
    
    5.0.0
    
    See Also:
    
    getXelVariable(String)
  - addVariableResolver
```
boolean addVariableResolver(VariableResolver resolver)
```
    Adds a variable resolver that will be used to resolve a variable by getXelVariable(java.lang.String).
    The new added variable resolver has the higher priority.
    Note: the variables resolver by the specified resolver are accessible to both zscript and EL expressions.
    
    Returns:
    
    whether the resolver is added successfully. Note: if the resolver was added before, it won't be added again and this method returns false.
  - removeVariableResolver
```
boolean removeVariableResolver(VariableResolver resolver)
```
    Removes a variable resolver that was added by addVariableResolver(org.zkoss.xel.VariableResolver).
    
    Returns:
    
    false if the resolver is not added before.
  - hasVariableResolver
```
boolean hasVariableResolver(VariableResolver resolver)
```
    Returns if the specified variable resolver has been registered
    
    Since:
    
    5.0.3
    
    See Also:
    
    addVariableResolver(org.zkoss.xel.VariableResolver)
  - addEventListener
```
boolean addEventListener(java.lang.String evtnm,
                         EventListener<? extends Event> listener)
```
    Adds an event listener to specified event for all components in this page.
    Due to performance consideration, unlike Component.addEventListener(int, java.lang.String, org.zkoss.zk.ui.event.EventListener<? extends org.zkoss.zk.ui.event.Event>), all event listeners for the page are deferrable, no matter Deferrable is implemented or not.
    Version Difference
    
    ZK 5.0 and earlier, the second registration is ignored if an event listener has been registered twice. However, since 6.0.0 and later, it won't be ignored. If a listener has been registered multiple times, it will be invoked multiple times.
    If you prefer to ignore the second registration, you could specify a library property called "org.zkoss.zk.ui.EventListener.duplicateIgnored" to true.
    
    Parameters:
    
    evtnm - what event to listen (never null)
    
    Returns:
    
    whether the listener is added successfully
    
    See Also:
    
    Component.addEventListener(int, java.lang.String, org.zkoss.zk.ui.event.EventListener<? extends org.zkoss.zk.ui.event.Event>)
  - removeEventListener
```
boolean removeEventListener(java.lang.String evtnm,
                            EventListener<? extends Event> listener)
```
    Removes an event listener.
    
    Returns:
    
    whether the listener is removed; false if it was never added.
  - isListenerAvailable
```
boolean isListenerAvailable(java.lang.String evtnm)
```
    Returns whether the event listener is available.
  - getListenerIterator
```
java.util.Iterator<EventListener<? extends Event>> getListenerIterator(java.lang.String evtnm)
```
    Deprecated. As of release 6.0, replaced with getEventListeners(java.lang.String). Returns an iterator for iterating the event listeners for the given event.
  - getEventListeners
```
java.lang.Iterable<EventListener<? extends Event>> getEventListeners(java.lang.String evtnm)
```
    Returns an iterable collection of the event listeners for the given event.
    Note: it is OK to invoke addEventListener(java.lang.String, org.zkoss.zk.ui.event.EventListener<? extends org.zkoss.zk.ui.event.Event>) or removeEventListener(java.lang.String, org.zkoss.zk.ui.event.EventListener<? extends org.zkoss.zk.ui.event.Event>) when iterating through the event listeners with the returned collection.
    To remove an event listener from the returned iterable collection, you could invoke Iterable.iterator()'s Iterator.remove().
    
    Since:
    
    6.0.0
  - removeComponents
```
void removeComponents()
```
    Removes all components in this page.
    
    See Also:
    
    Execution.createComponents(String,Component,Map)
  - invalidate
```
void invalidate()
```
    Invalidates this page to cause all components to redraw.
  - interpret
```
void interpret(java.lang.String zslang,
               java.lang.String script,
               Scope scope)
```
    Interprets a script in the specified scripting language in the context of the specified scope.
    
    Parameters:
    
    zslang - the scripting language. If null, getZScriptLanguage() is assumed.
    
    scope - the scope used as the context. Since a component is a scope, you can pass a component as the context. By context we mean the attribute of the scope, its space owner, spacer owner's space owner, page and desktop will be searched. If null, this page is assumed.
    
    Since:
    
    5.0.0
  - getInterpreter
```
Interpreter getInterpreter(java.lang.String zslang)
```
    Returns the interpreter of the specified scripting language.
    The interpreter will be loaded and initialized, if it is not loaded yet.
    
    Parameters:
    
    zslang - the scripting language. If null, getZScriptLanguage() is assumed.
    
    Throws:
    
    InterpreterNotFoundException - if not found.
  - getLoadedInterpreters
```
java.util.Collection<Interpreter> getLoadedInterpreters()
```
    Returns all loaded interpreters.
  - getZScriptLanguage
```
java.lang.String getZScriptLanguage()
```
    Returns the default scripting language which is assumed when a zscript element doesn't specify any language.
    
    Returns:
    
    the default scripting language, say, Java. Never null.
  - setZScriptLanguage
```
void setZScriptLanguage(java.lang.String zslang)
                 throws InterpreterNotFoundException
```
    Sets the default scripting language which will be assumed if a zscript element doesn't specify any language.
    
    Throws:
    
    InterpreterNotFoundException - if no such language
  - getExpressionFactoryClass
```
java.lang.Class<? extends ExpressionFactory> getExpressionFactoryClass()
```
    Returns the implementation of the expression factory that is used by this page, or null if Configuration.getExpressionFactoryClass() is used.
    Default: null.
    
    Since:
    
    3.0.4
    
    See Also:
    
    setExpressionFactoryClass(java.lang.Class<? extends org.zkoss.xel.ExpressionFactory>)
  - setExpressionFactoryClass
```
void setExpressionFactoryClass(java.lang.Class<? extends ExpressionFactory> expfcls)
```
    Sets the implementation of the expression factory that is used by this page.
    
    Parameters:
    
    expfcls - the class that implements ExpressionFactory, If null, Configuration.getExpressionFactoryClass() is used.
    
    Since:
    
    3.0.4
    
    See Also:
    
    getExpressionFactoryClass()
  - isComplete
```
boolean isComplete()
```
    Returns if this page is a complete page. By complete we mean the page has everything that the client expects. For example, for HTML browsers, the page will generate the HTML, HEAD and BODY tags.
    It is meaningful only if it is the top-level page (i.e., not included by the include component).
    Default: false. It means ZK loader will enclose the page content with HTML/HEAD/BODY if necessary (such as not included by other Servlet).
    If you have a page that has a complete HTML page and it is included by other page, you have to specify the complete flag to be true.
    
    Since:
    
    3.0.4
  - setComplete
```
void setComplete(boolean complete)
```
    Sets if the page is a complete page.
    Default: false. It means a page is complete if and only if it is not included by other page.
    
    Parameters:
    
    complete - whether the page is complete. If true, this page is assumed to be complete no matter it is included or not. If false, this page is assumed to be complete if it is not included by other page.
    
    Since:
    
    3.0.4
    
    See Also:
    
    isComplete()
  - getFunctionMapper
```
FunctionMapper getFunctionMapper()
```
    Returns the function mapper for resolving XEL functions, or null if not available. The function mapper represents all function mappers being added.
    
    Since:
    
    3.0.0
  - addFunctionMapper
```
boolean addFunctionMapper(FunctionMapper mapper)
```
    Adds the function mapper in addition to the current one.
    The new added function mapper has the higher priority. getFunctionMapper() will return the new
    
    Parameters:
    
    mapper - the new function mapper (null to ignore).
  - removeFunctionMapper
```
boolean removeFunctionMapper(FunctionMapper mapper)
```
    Removes a function mapper that was added by addFunctionMapper(org.zkoss.xel.FunctionMapper).
    
    Returns:
    
    false if the mapper is not added before.
    
    Since:
    
    5.0.8
  - hasFunctionMapper
```
boolean hasFunctionMapper(FunctionMapper mapper)
```
    Returns if the specified function mapper has been registered
    
    Since:
    
    5.0.8
    
    See Also:
    
    addFunctionMapper(org.zkoss.xel.FunctionMapper)
  - getLanguageDefinition
```
LanguageDefinition getLanguageDefinition()
```
    Returns the language definition that this page belongs to (never null).
  - getComponentDefinitionMap
```
ComponentDefinitionMap getComponentDefinitionMap()
```
    Returns the map of component definitions (never null).
    Note: the map is shared among all instance of the same page definition. Any component definition added (by ComponentDefinitionMap.add(org.zkoss.zk.ui.metainfo.ComponentDefinition)) are visible to all other instances of the same page definition. Thus, it is NOT a good idea to change its content.
  - getComponentDefinition
```
ComponentDefinition getComponentDefinition(java.lang.String name,
                                           boolean recurse)
```
    Returns the component definition of the specified name, or null if not found.
    Note: unlike LanguageDefinition.getComponentDefinition(java.lang.String), this method doesn't throw ComponentNotFoundException if not found. It just returns null.
    
    Parameters:
    
    recurse - whether to look up the component from getLanguageDefinition()
  - getComponentDefinition
```
ComponentDefinition getComponentDefinition(java.lang.Class<? extends Component> cls,
                                           boolean recurse)
```
    Returns the component definition of the specified class, or null if not found.
    Note: unlike LanguageDefinition.getComponentDefinition(java.lang.String), this method doesn't throw ComponentNotFoundException if not found. It just returns null.
    
    Parameters:
    
    recurse - whether to look up the component from getLanguageDefinition()
  - addTemplate
```
void addTemplate(java.lang.String name,
                 Template template)
```
    Adds page scope template
    
    Parameters:
    
    name -
    
    template -
    
    Since:
    
    8.0.0
  - removeTemplate
```
void removeTemplate(java.lang.String name)
```
    Removes page scope template
    
    Parameters:
    
    name -
    
    Since:
    
    8.0.0
  - getTemplate
```
Template getTemplate(java.lang.String name)
```
    Gets page scope template by name
    
    Parameters:
    
    name -
    
    Since:
    
    8.0.0

Interface Page

Desktop

Inter-page Communication

Field Summary

Method Summary

Methods inherited from interface org.zkoss.zk.ui.IdSpace

Methods inherited from interface org.zkoss.zk.ui.ext.Scope

Field Detail

PAGE_SCOPE

DESKTOP_SCOPE

SESSION_SCOPE

APPLICATION_SCOPE

REQUEST_SCOPE

Method Detail

getId

setId

getUuid

getTitle

setTitle

getStyle

setStyle

getViewport

setViewport

getRequestPath

isAlive

getDesktop

getRoots

getFirstRoot

getLastRoot

getAttributes

getAttributes

getAttribute

getAttribute

hasAttribute

hasAttribute

setAttribute

setAttribute

removeAttribute

removeAttribute

getAttributeOrFellow

hasAttributeOrFellow

resolveClass

addClassResolver

getZScriptClass

getZScriptFunction

getZScriptFunction

getZScriptVariable

getZScriptVariable

getXelVariable

getXelVariable

addVariableResolver

removeVariableResolver

hasVariableResolver

addEventListener

Version Difference

removeEventListener

isListenerAvailable

getListenerIterator

getEventListeners

removeComponents

invalidate

interpret

getInterpreter

getLoadedInterpreters

getZScriptLanguage

setZScriptLanguage

getExpressionFactoryClass

setExpressionFactoryClass

isComplete

setComplete

getFunctionMapper

addFunctionMapper

removeFunctionMapper

hasFunctionMapper

getLanguageDefinition

getComponentDefinitionMap

getComponentDefinition

getComponentDefinition

addTemplate

removeTemplate