06_ImplementingDataBinding

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Copyright 2010, Oracle and/or its affiliates. All rights reserved.

Implementing Data Binding Concepts


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Copyright 2010, Oracle and/or its affiliates. All rights reserved.6 - 2

Objectives

After completing this lesson, you should be able to do the

following:

Describe the scope and role of the binding files Define Application Development Framework (ADF) Model

binding types

Define ADF Model executables and how to use them Manage data-bound components with the page definition

file

Bind data by using Expression Language (EL)


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Agenda

Defining ADF Model binding

Describing the scope and role of the binding files

Managing data-bound components with the pagedefinition file

Data control and Business Components (BC)


4/40Copyright 2010, Oracle and/or its affiliates. All rights reserved.6 - 4

What Is Data Binding?

It is a declarative data binding facility.

It implements the JSR-227 specification.

Implemented as the data control for: Any business service

Any UI



The Heart of ADF: ADFm

Relational Data XML Data Packaged AppsLegacy Data

BusinessServices

DataServices

Model

Controller

JSP View

Desktop Browser-based

Struts

ADF Model (JSR-227)

Java EJB

Toplink

OfficeADF Swing

BAM ADF BC PortletBI XMLBPEL WebServices

JSF/ADF Controller

JSF ADF Faces



ADF Model Data Control Concepts

Abstracts the implementation of Business Services

Uses standard metadata interface to describe the services

operations and data collection At design time, simplifies binding components to the data

control operation or the data collection

At run time, wires business service data controls to UIbindings from XML files

Has the following benefits:

You write less code.

You work the same way with any UI and Business Service

technology.

You gain useful run-time features because you do not have

to code them yourself.



Application Module in the Data Control Palette

ADF BC data controls are

exposed through an

application module. Data controls are usable

with the drag-and-drop

functionality.


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Nested Application Modules


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Changing the Application Module

Data Control NameYou can change the default application module name of the

data control.


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ADF Data Bindings Concepts

Data bindings abstract the details of how to access data

from data collections and how to invoke its operations.

There are three kinds of data binding objects: Iterator bindings to bind to an iterator that tracks the current

row in a data collection (Results returned to the page)

Value bindings to connect the UI components to the

attributes in a data collection (Text values entered on thepage)

Action bindings to invoke custom or built-in operations on a

data control or its data collections (The Create button)


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Business Services

User interface

Data controls

Data bindings

ADFm: Data Controls and Data Bindings


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ADF Model: Overview

A binding exposes a property or table from the underlying

model in a generic EL-accessible way.

ADFm

bindings

Text

binding

Action

binding

List

binding

Table

binding

Data

control


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ADF Model Bindings

Each page has its own set of bindings.

All the bindings for a given page are defined in a

PageDef.xml file. PageDefinition is also called BindingContainer.

The mapping from viewId to pageDef isin the DataBindings.cpx file.

PageDefinition

browsePageDef.xml

Text

binding

Action

binding

List

binding

Table

binding

#{bindings.DeptView}

viewId

browse.jspx

BindingContext

DataBindings.cpx


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Agenda



Managing data-bound components with the page definitionfile



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DataBindings.cpx File

Provides the metadata from which the Oracle ADF binding

objects are created at run time

Uses XML syntax Specifies:


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DataBindings.cpx File: Details

Locates the correct PageDef for a page

Defines the data control usage of the project


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DataBindings.cpx Properties:

Synchronization Mode Use Immediate mode for

performance (now the

default). Batch mode is best reserved

for n-tier.


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Agenda






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PageDef.xml File

The key data binding artifact:

Is accessible through the visual editors context menu or

the link on its Bindings tab Describes the service usage of a particular page, panel, orregion

XML file content:

Default location controlled by the ADFm Settings >PageDef subpackage project property

Run-time location determined by the DataBindings.cpxfile (see CpxFileName in web.xml)

Three sections (in order of interest, and not appearance):

1. Bindings

2. Executables

3. Parameters


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Examining a Page Definition File

The file displays in:

The Structure pane

The editor Three sections are displayed, with

detailed bindings in each.


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Bindings Sections

The data is accessed via the

bindings object on the HTTP

request, conventionally via EL:#{bindings.ProdId}

#{bindings} provides

access to everything that is defined in the Binding Container

or page definition. Individual bindings (such as Table Bindings):

Are objects

Have attributes other

than value Are accessible using EL

Example:#{bindings.Products.rangesize}


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Identifying Types of Bindings

There are several types of generic bindings.


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Types of Bindings: Attribute

Attribute binding binds the inputText component to aString value.

In this example, the binding has a validate method thatmust be called before the binding is updated.

Use the tag to call this method.

Boolean attribute binding: Convert between any underlying

database type (0 or 1, true or false, yes or no, and soon) and a primitive Boolean object.


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Types of Bindings: List

List binding: Exports a list of legal values, enabling the user to

select one


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Types of Bindings: Action

Action binding example: A binding to an ADFm built-in

operation (can also bind to a business method)


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Using View-Level Operations in Action Bindings:Setting the Current Row

setCurrentRowWithKey:

The rowKey parameter is a serialized view row key, such as:

000200000002C20200000002C102000000010000010A5AB7DAD9.

For example:

#{bindings.SomeAttrName.rowKeyStr}#{row.rowKeyStr}

setCurrentRowWithKeyValue:

The rowKey parameter is the literal key

value for a single-attribute key.

For example, 1001 is used to findthe order number 1001.


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Using View-Level Operations in Action Bindings:Inserting a New Row

Use CreateInsert for:

An editable table control

A table with a single, currenteditable row

A master or detail page if you

want the newly created master

row to correctly show noexisting detail rows


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Create and CreateInsert

The Create operation performs the following code:

In addition, the CreateInsert operation performs:

// insert new row into view object's default rowset

yourViewObject.insertRow(newRow);

// create a new row for the view object

Row newRow = yourViewObject.createRow();// mark the row as being "initialized", but not yet new

newRow.setNewRowState(Row.STATUS_INITIALIZED);


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Binding Objects in the Executables Section

The executables element of the page definition file defines thefollowing types of executable binding objects:

iterator: Is the basic link from data to binding

methodIterator: Links the results of a method call to a

binding

accessorIterator: Links to detail collections for nested

objects variableIterator: Accesses data,

which is local to the page definition file

invokeAction: Allows automatic

life-cycle invocation of amethod binding


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Controlling the Execution of Executables

Executables are evaluated in the order in which they appear in

the page definition file.

Executables may be further controlled by using: The Refresh property: Executes when in the life cycle

RefreshCondition and RefreshAfter: Whether to execute

Example:

Note: Pay attention to side effects. Double invocation when bindings

are based on a method iterator implicitly invokes the method.

RefreshCondition="${(CartBean.cartId != null || orderBean.status == OPEN}"


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Leveraging Iterators

Working with multiple row sets and row set iterators:

Use View Object as the default row set.

Create secondary row sets based on the same VO. Create multiple row sets for different bind variable values.

The following methods are available:

createRowSet() createRowSetIterator()

findRowSetIterator()

closeRowSetIterator()

closeRowSetIterator()


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Binding Objects in the Parameters Section

The parameters element of the page definition file defines the

parameters for the page.

Parameter binding objects declare the parameters that thepage evaluates at the beginning of a request.

Page parameters are evaluated once during the Prepare

Model phase.

Define the value of a parameter in the page definition file

by using:

Static values

Binding expressions An EL expression, which

assigns a static value


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Agenda






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Data Controls and Standard Metadata Interfaces

Data controls describe Business Services by using standard

metadata interfaces.

View Object instancesin the active data model

Custom method in the

client interfaceMethod arguments

Application

module operations

Application Module

Data controls

Data controls created

from Java classes (beans)


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Working with Named Bind Variables

Two alternative ways of working with bind variables:

Using the custom VO finder operation

Using the built-in ExecuteWithParams operation


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Transaction Control Operations

Built-in transaction control operations are:

Generic operations

Usable with any View Object component

Built-in transaction

control operations

S h i R i f Q P


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Schematic Representation of a Query Process

1 2

3

4

5

6

7

8

9

S


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Summary

In this lesson, you should have learned how to:

Describe the scope and role of the binding files

Define ADF Model binding types Define ADF Model executables and how to use them

Manage data-bound components with the page definition

file

Bind data using EL

P ti 6 O i


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Practice 6 Overview:

Implementing Data Binding Concepts

This practice covers the following topics:

Diagnosing an application problem

Building binding manually

06_ImplementingDataBinding

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