com.vaadin.flow.data.renderer

Class Renderer<SOURCE>

java.lang.Object

com.vaadin.flow.data.renderer.Renderer<SOURCE>

Type Parameters:

SOURCE - the type of the input object used inside the template

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ColumnPathRenderer, ComponentRenderer, EditorRenderer, LitRenderer, TemplateRenderer

public class Renderer<SOURCE>
extends Object
implements Serializable

Base class for all renderers - classes that take a given model object as input and outputs a set of elements that represents that item in the UI.

Author:

Vaadin Ltd

See Also:

ValueProvider, ComponentRenderer, LitRenderer, https://www.polymer-project.org/2.0/docs/devguide/templates, Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Renderer() Default constructor.
protected	Renderer(String template) Deprecated. since Vaadin 22

Method Summary

Modifier and Type	Method and Description
Map<String,SerializableConsumer<SOURCE>>	getEventHandlers() Deprecated. since Vaadin 22
Map<String,ValueProvider<SOURCE,?>>	getValueProviders() Gets the property mapped to ValueProviders in this renderer.
Rendering<SOURCE>	render(Element container, DataKeyMapper<SOURCE> keyMapper) Handles the rendering of the model objects by creating a new <template> element in the given container.
Rendering<SOURCE>	render(Element container, DataKeyMapper<SOURCE> keyMapper, Element contentTemplate) Deprecated. since Vaadin 22
protected void	setEventHandler(String handlerName, SerializableConsumer<SOURCE> handler) Deprecated. since Vaadin 22
protected void	setProperty(String property, ValueProvider<SOURCE,?> provider) Deprecated. since Vaadin 22

Methods inherited from class java.lang.Object

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

Constructor Detail

Renderer

protected Renderer()

Default constructor.

Renderer

@Deprecated
protected Renderer(String template)

Deprecated. since Vaadin 22

Builds a renderer with the specified template.

Parameters:

template - the template used by the renderer

Method Detail

setProperty

@Deprecated
protected void setProperty(String property,
                                       ValueProvider<SOURCE,?> provider)

Deprecated. since Vaadin 22

Sets a property to be used inside the template. Each property is referenced inside the template by using the [[item.property]] syntax.

Examples:

 
 // Regular property
 TemplateRenderer.<Person> of("<div>Name: [[item.name]]</div>")
          .withProperty("name", Person::getName);

 // Property that uses a bean. Note that in this case the entire "Address" object will be sent to the template.
 // Note that even properties of the bean which are not used in the template are sent to the client, so use
 // this feature with caution.
 TemplateRenderer.<Person> of("<span>Street: [[item.address.street]]</span>")
          .withProperty("address", Person::getAddress);

 // In this case only the street field inside the Address object is sent
 TemplateRenderer.<Person> of("<span>Street: [[item.street]]</span>")
          .withProperty("street", person -> person.getAddress().getStreet());
 
 

Any types supported by the JsonSerializer are valid types for the Renderer.

Parameters:

property - the name of the property used inside the template, not null

provider - a ValueProvider that provides the actual value for the property, not null

setEventHandler

@Deprecated
protected void setEventHandler(String handlerName,
                                           SerializableConsumer<SOURCE> handler)

Deprecated. since Vaadin 22

Sets an event handler for events from elements inside the template. Each event is referenced inside the template by using the on-event syntax.

Examples:

 
 // Standard event
 TemplateRenderer.of("<button on-click='handleClick'>Click me</button>")
          .withEventHandler("handleClick", object -> doSomething());

 // You can handle custom events from webcomponents as well, using the same syntax
 TemplateRenderer.of("<my-webcomponent on-customevent=
    'onCustomEvent'></my-webcomponent>")
          .withEventHandler("onCustomEvent", object -> doSomething());
 
 

The name of the function used on the on-event attribute should be the name used at the handlerName parameter. This name must be a valid Javascript function name.

Parameters:

handlerName - the name of the handler used inside the on-event="handlerName", not null

handler - the handler executed when the event is triggered, not null

See Also:

https://www.polymer-project.org/2.0/docs/devguide/events

render

public Rendering<SOURCE> render(Element container,
                                DataKeyMapper<SOURCE> keyMapper)

Handles the rendering of the model objects by creating a new <template> element in the given container.

Parameters:

container - the element in which the template will be attached to

keyMapper - mapper used internally to fetch items by key and to provide keys for given items. It is required when either event handlers or DataGenerator are supported

Returns:

the context of the rendering, that can be used by the components to provide extra customization

render

@Deprecated
public Rendering<SOURCE> render(Element container,
                                            DataKeyMapper<SOURCE> keyMapper,
                                            Element contentTemplate)

Deprecated. since Vaadin 22

Handles the rendering of the model objects by using the given <template> element in the given container.

Subclasses of Renderer usually override this method to provide additional features.

Parameters:

container - the element in which the template will be attached to, not null

keyMapper - mapper used internally to fetch items by key and to provide keys for given items. It is required when either event handlers or DataGenerator are supported

contentTemplate - the <template> element to be used for rendering in the container, not null

Returns:

the context of the rendering, that can be used by the components to provide extra customization

getValueProviders

public Map<String,ValueProvider<SOURCE,?>> getValueProviders()

Gets the property mapped to ValueProviders in this renderer. The returned map is immutable.

Returns:

the mapped properties, never null

getEventHandlers

@Deprecated
public Map<String,SerializableConsumer<SOURCE>> getEventHandlers()

Deprecated. since Vaadin 22

Gets the event handlers linked to this renderer. The returned map is immutable.

Returns:

the mapped event handlers, never null

See Also:

setEventHandler(String, SerializableConsumer)