IBM Workplace Forms: Guide to Building and Integrating a Sample Workplace Forms Application

Chapter 4. Building the base scenario: Stage 1 105

This block of XML allows for arbitrary data, meaning that it can contain any data and can be

formatted in any manner. Furthermore, individual elements in the data model can be bound to

one or more elements in the form description. This binding causes the elements to share

data. If one element is changed, the other elements are updated to mirror that change.

This allows you to create a separate block of data within the form, format it any way you like,

and bind it to form elements so that data entered by the user is automatically copied to the

data model. For example, you could include the block of data that is required by an application

(such as an IBM Content Manager based system), format the data so that it complies with a

specific schema, and then bind that data model to the form description.

The result is a block of XML data that can be structured to meet any needs, extracted easily

by other applications, and transmitted without the rest of the form.

4.7.2 Creating XML bindings

Once you have created a data instance, you need to bind the data elements. A bind creates a

link between two elements in the form. This link causes those elements to share information,

meaning that if one of the elements is changed, the other element is updated to mirror that

change.

There are two types of binds:

򐂰 Data element to form element:

In this case, one element in the data instance is bound to one option in the form

description. This type of bind links your data model to the form description, so that

information entered by the user is copied to your data model. For example, you might

create a bind that links the firstName element in your data instance to the

firstNameField.value option in your form description.

򐂰 Data element to data element:

In this case, one element in the data instance is bound to another element in the data

model. This type of bind is often used to perform special calculations or to copy

information from one part of the data model to another. For example, you might have a

data holder element that performs a calculation. You could then bind this element to copy

the result of the calculation into your data instance.

Each bind creates a one-to-one relationship: one data element to one data or form element.

However, you can also create a one-to-many relationship — one data element to many data

or form elements — by creating additional binds. For example, you could bind the firstName

data element to both the firstName field on page one of the form and the firstName field on

page two of the form. All of the bindings are contained within a <bindings> tag in the data

model, as shown:bind a form element to more than one data element.

An XML binding is a way of linking the fields on your form to the XML instance that describes

the captured data.

The following steps describe how to use the XML Data dialog to create your XML bindings:

1. Open the XML Data Model dialog from the toolbar, Tools → XML Data Model →

Create/Edit Manually, and click the Bindings tab.

2. Click the button that looks like a file menu and then select a data element from the XML

instance.

3. Click the button with the hand icon; the workspace will be brought to the front. Select the

corresponding field.

4. Click the Add button to add the binding to the list.