Class Renderer<T extends UIComponent>
- java.lang.Object
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- jakarta.faces.render.Renderer<T>
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- Type Parameters:
T
- The component class.
- Direct Known Subclasses:
RendererWrapper
public abstract class Renderer<T extends UIComponent> extends Object
A Renderer converts the internal representation of
UIComponent
s into the output stream (or writer) associated with the response we are creating for a particular request. EachRenderer
knows how to render one or moreUIComponent
types (or classes), and advertises a set of render-dependent attributes that it recognizes for each supportedUIComponent
.Families of
Renderer
s are packaged as aRenderKit
, and together support the rendering of all of theUIComponent
s in a view associated with aFacesContext
. Within the set ofRenderer
s for a particularRenderKit
, each must be uniquely identified by therendererType
property.Individual
Renderer
instances will be instantiated as requested during the rendering process, and will remain in existence for the remainder of the lifetime of a web application. Because each instance may be invoked from more than one request processing thread simultaneously, they MUST be programmed in a thread-safe manner.If the
ListenerFor
annotation is attached to the class definition of aRenderer
, that class must also implementComponentSystemEventListener
, and the action pertaining to the processing ofResourceDependency
on aRenderer
described inListenerFor
must be taken.If the
ResourceDependency
annotation is attached to the class definition of aRenderer
, the action pertaining to the processing ofResourceDependency
on aRenderer
described inUIComponent.getChildren()
must be taken.The generic parameter T represents the component class.
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Field Summary
Fields Modifier and Type Field Description static String
PASSTHROUGH_RENDERER_LOCALNAME_KEY
The key in the component passthrough attributesMap
for the localName of the element corresponding to the component.
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Constructor Summary
Constructors Constructor Description Renderer()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description String
convertClientId(FacesContext context, String clientId)
Convert the component generated client id to a form suitable for transmission to the client.void
decode(FacesContext context, T component)
Decode any new state of the specifiedUIComponent
from the request contained in the specifiedFacesContext
, and store that state on theUIComponent
.void
encodeBegin(FacesContext context, T component)
Render the beginning specifiedUIComponent
to the output stream or writer associated with the response we are creating.void
encodeChildren(FacesContext context, T component)
Render the child components of thisUIComponent
, following the rules described forencodeBegin()
to acquire the appropriate value to be rendered.void
encodeEnd(FacesContext context, T component)
Render the ending of the current state of the specifiedUIComponent
, following the rules described forencodeBegin()
to acquire the appropriate value to be rendered.Object
getConvertedValue(FacesContext context, UIComponent component, Object submittedValue)
Attempt to convert previously stored state information into an object of the type required for this component (optionally using the registeredConverter
for this component, if there is one).boolean
getRendersChildren()
Return a flag indicating whether thisRenderer
is responsible for rendering the children the component it is asked to render.
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Field Detail
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PASSTHROUGH_RENDERER_LOCALNAME_KEY
public static final String PASSTHROUGH_RENDERER_LOCALNAME_KEY
The key in the component passthrough attributes
Map
for the localName of the element corresponding to the component.- Since:
- 2.2
- See Also:
- Constant Field Values
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Method Detail
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decode
public void decode(FacesContext context, T component)
Decode any new state of the specified
UIComponent
from the request contained in the specifiedFacesContext
, and store that state on theUIComponent
.During decoding, events may be enqueued for later processing (by event listeners that have registered an interest), by calling
queueEvent()
on the associatedUIComponent
.- Parameters:
context
-FacesContext
for the request we are processingcomponent
-UIComponent
to be decoded.- Throws:
NullPointerException
- ifcontext
orcomponent
isnull
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encodeBegin
public void encodeBegin(FacesContext context, T component) throws IOException
Render the beginning specified
UIComponent
to the output stream or writer associated with the response we are creating. If the conversion attempted in a previous call togetConvertedValue()
for this component failed, the state information saved during execution ofdecode()
should be used to reproduce the incorrect input.- Parameters:
context
-FacesContext
for the request we are processingcomponent
-UIComponent
to be rendered- Throws:
IOException
- if an input/output error occurs while renderingNullPointerException
- ifcontext
orcomponent
is null
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encodeChildren
public void encodeChildren(FacesContext context, T component) throws IOException
Render the child components of this
UIComponent
, following the rules described forencodeBegin()
to acquire the appropriate value to be rendered. This method will only be called if therendersChildren
property of this component istrue
.- Parameters:
context
-FacesContext
for the response we are creatingcomponent
-UIComponent
whose children are to be rendered- Throws:
IOException
- if an input/output error occurs while renderingNullPointerException
- ifcontext
orcomponent
isnull
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encodeEnd
public void encodeEnd(FacesContext context, T component) throws IOException
Render the ending of the current state of the specified
UIComponent
, following the rules described forencodeBegin()
to acquire the appropriate value to be rendered.- Parameters:
context
-FacesContext
for the response we are creatingcomponent
-UIComponent
to be rendered- Throws:
IOException
- if an input/output error occurs while renderingNullPointerException
- ifcontext
orcomponent
isnull
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convertClientId
public String convertClientId(FacesContext context, String clientId)
Convert the component generated client id to a form suitable for transmission to the client.
The default implementation returns the argument
clientId
unchanged.- Parameters:
context
-FacesContext
for the current requestclientId
- the client identifier to be converted to client a specific format.- Returns:
- the converted
clientId
- Throws:
NullPointerException
- ifcontext
orclientId
isnull
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getRendersChildren
public boolean getRendersChildren()
Return a flag indicating whether this
Renderer
is responsible for rendering the children the component it is asked to render. The default implementation returnsfalse
.- Returns:
- the current value of the flag
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getConvertedValue
public Object getConvertedValue(FacesContext context, UIComponent component, Object submittedValue) throws ConverterException
Attempt to convert previously stored state information into an object of the type required for this component (optionally using the registered
Converter
for this component, if there is one). If conversion is successful, the new value should be returned from this method; if not, aConverterException
should be thrown.- Parameters:
context
-FacesContext
for the request we are processingcomponent
-UIComponent
to be decoded.submittedValue
- a value stored on the component duringdecode
.- Returns:
- the converted value
- Throws:
ConverterException
- if the submitted value cannot be converted successfully.NullPointerException
- ifcontext
orcomponent
isnull
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