Oracle Fusion Middleware Tag Reference for Oracle ADF Faces 12c (12.2.1.4.0) E81455-03

# <af:streaming>

af:streaming streaming streaming

UIComponent class: oracle.adf.view.rich.component.rich.data.RichStreaming
Component type: oracle.adf.RichStreaming

The streaming component may be used to render content that requires model data to be loaded first. It allows the initial component with a placeholder to be rendered while the data is being loaded without holding up the rest of the page from rendering. Streaming Model

The streaming component needs an `oracle.adf.view.rich.model.AsyncFetch` object to specify the data that is to be loaded asynchronously. The fetch constraints may be passed via EL via the constraints attribute.

This component does not render any DOM that affects geometry and does not wrap its children with a DOM element.

## Code Example(s)

    <af:streaming value="#{myManagedBean.asyncFetchObject}"
                  constraints="#{myManagedBean.asyncFetchConstraints}"
                  id="s1">
      <f:facet name="placeholder">
        <af:outputText value="Please wait..." id="ot1"/>
      </f:facet>

      <af:outputText value="#{myManagedBean.fetchedValue}" id="ot2"/>
    </af:streaming>

## Events

Type | Phases | Description
--- | --- | ---
org.apache.myfaces.trinidad.event.AttributeChangeEvent | Invoke, Application, Apply, Request, Values | Event delivered to describe an attribute change. Attribute change events are not delivered for any programmatic change to a property. They are only delivered when a renderer changes a property without the application's specific request. An example of an attribute change event might include the width of a column that supported client-side resizing.

## Supported Facets

Name | Description
--- | ---
placeholder | Render a placeholder when the data is not available yet. As with JSP pages, when using Facelets, multiple components are not allowed in this facet.

## Attributes

Name | Type | Supports EL? | Description
attributeChangeListener | javax.el.MethodExpression | Only EL | a method reference to an attribute change listener. Attribute change events are not delivered for any programmatic change to a property. They are only delivered when a renderer changes a property without the application's specific request. An example of an attribute change events might include the width of a column that supported client-side resizing.
binding | oracle.adf.view.rich.component.rich.data.RichStreaming | Only EL | an EL reference that will store the component instance on a bean. This can be used to give programmatic access to a component from a backing bean, or to move creation of the component to a backing bean.
clientComponent | boolean | Yes | Default Value: false whether a client-side component will be generated. A component may be generated whether or not this flag is set, but if client Javascript requires the component object, this must be set to true to guarantee the component's presence. Client component objects that are generated today by default may not be present in the future; setting this flag is the only way to guarantee a component's presence, and clients cannot rely on implicit behavior. However, there is a performance cost to setting this flag, so clients should avoid turning on client components unless absolutely necessary. For the components outputText and outputFormatted, setting the clientComponent to true will render id attribute for the html DOM. This ID attribute can alternatively be generated by setting oracle.adf.view.rich.SUPPRESS_IDS to "auto" in web.xml.
constraints | Object | Yes | The streaming constraints to be used during the fetch. Defaults to null if not specified.
id | String | No | the identifier for the component. Every component may be named by a component identifier that must conform to the following rules: They must start with a letter (as defined by the Character.isLetter() method) or underscore ( _ ). Subsequent characters must be letters (as defined by the Character.isLetter() method), digits as defined by the Character.isDigit() method, dashes ( - ), or underscores ( _ ). To minimize the size of responses generated by JavaServer Faces, it is recommended that component identifiers be as short as possible. If a component has been given an identifier, it must be unique in the namespace of the closest ancestor to that component that is a NamingContainer (if any).
partialTriggers | String[] | Yes | the IDs of the components that should trigger a partial update. This component will listen on the trigger components. If one of the trigger components receives an event that will cause it to update in some way, this component will request to be updated too. Identifiers are relative to the source component (this component), and must account for NamingContainers. If your component is already inside of a naming container, you can use a single colon to start the search from the root of the page, or multiple colons to move up through the NamingContainers - "::" will pop out of the component's naming container (or itself if the component is a naming container) and begin the search from there, ":::" will pop out of two naming containers (including itself if the component is a naming container) and begin the search from there, etc.
rendered | boolean | Yes | Default Value: true whether the component is rendered. When set to false, no output will be delivered for this component (the component will not in any way be rendered, and cannot be made visible on the client). If you want to change a component's rendered attribute from false to true using PPR, set the partialTrigger attribute of its parent component so the parent refreshes and in turn will render this component.
value | oracle.adf.view.rich.model.AsyncFetch | Yes | The value of the component, providing an implementation of AsyncFetch.