To configure the FixedWidth data handler, take the following
steps:
- Enter the appropriate values for the attributes of the
FixedWidth child meta-object.
- Create or modify business object definitions so that they
support the data handler.
Each of these steps is described in more detail in the following
sections.
To configure a FixedWidth data handler, you must ensure that its
configuration information is provided in the FixedWidth child
meta-object. For the FixedWidth data handler, IBM delivers the
MO_DataHandler_DefaultFixedWidthConfig child meta-object. Each
attribute in this meta-object defines a configuration property for
the FixedWidth data handler. Table 54
describes the attributes for this child meta-object.
Table 54. Child
meta-object attributes for the FixedWidth data handler
Meta-object
attribute name |
Meaning |
Delivered
default value |
ClassName
|
Name of the
data handler class to load for use with the MIME type that matches
the name of the attribute in the top-level data-handler
meta-object. This attribute has the FixedWidth child meta-object as
its type. |
com.crossworlds. DataHandlers. text.fixedwidth |
Alignment
|
Adds or
removes the
PadCharacter attribute. For event processing, pad
characters are trimmed. For request processing, pad characters are
added. Possible values are BOTH, LEFT, and
RIGHT. For example, "LEFT" alignment means the
value of the business object attributes moves to the extreme left
of the space for that attribute value. "BOTH" alignment
for event notification means that pad characters are trimmed off
both the left and right sides. "RIGHT" alignment for
request processing means that the right side is padded with pad
characters. |
BOTH |
BOCountSize
|
Specifies the
space allocated for the total number of business objects being
processed. |
3 |
BONameSize
|
Specifies the
space allocated for the name of the business object. |
50 |
BOVerbSize
|
Specifies the
space allocated for the verb. |
20 |
CxBlank
|
When
converting from a business object, the FixedWidth data handler
writes the value configured for the Default Value property of the
CxBlank meta-object attribute to the fixed-width document
whenever it encounters a business object attribute whose value is
CxBlank. When
converting to a business object, the FixedWidth data handler
assigns the value configured for the Default Value property of the
CxBlank meta-object attribute to the business object
attribute's value whenever it encounters the value of this
CxBlank meta-object attribute in the fixed-width document.
Business objects must have at least one primary key that does
not contain the value CxBlank at runtime. |
CxBlank value |
CxIgnore
|
When
converting from a business object, the FixedWidth data handler
writes the value configured for the Default Value property of the
CxIgnore meta-object attribute to the fixed-width document
whenever it encounters a business object attribute whose value is
CxIgnore. When
converting to a business object, the FixedWidth data handler
assigns the value configured for the Default Value property of the
CxIgnore meta-object attribute to the business object
attribute's value whenever it encounters the value of this
CxIgnore meta-object attribute in the fixed-width
document. Business objects must have at least one primary key that
does not contain the value CxIgnore at
runtime. |
CxIgnore value |
DummyKey
|
Key attribute
required by the business integration system. |
1 |
OmitObjectEventId
|
Boolean value
to determine whether or not to include ObjectEventId data
in business-object-to-string and string-to-business-object
conversions. |
false |
PadCharacter
|
Indicates
spaces to add or remove for alignment. You can specify any
character as the pad character. |
# |
Truncation
|
Sets removal
of characters. If true, any attribute value in the
business object that is greater than MaxLength is
truncated to MaxLength during request processing. If
false, an error is logged and formatting stops. |
false |
ObjectEventId |
Placeholder
not used by the data handler but required by the business
integration system. |
none |
The "Delivered default value" column in Table 54 lists the value in the Default Value
property for the corresponding attribute in the delivered business
object. You must examine your environment and set the Default Value
properties of those attributes to the appropriate values for your
system and your FixedWidth documents. You must make sure that at
least the ClassName attribute has a default value.
- Note:
- Use Business Object Designer Express to modify business object
definitions.
The FixedWidth data handler makes assumptions about the
structure of the business objects that it handles. Therefore, when
you create a business object for conversion using the FixedWidth
data handler, follow these rules:
- Make sure that every attribute in the business object
definition has an appropriate MaxLength property value.
This ensures that the FixedWidth data handler can properly process
the conversion of data from a business object to a FixedWidth
format and from a FixedWidth format to a business object.
- Make sure that the
ObjectEventId attribute is included in every business object
at all levels of a business object hierarchy. Business Object
Designer Express does this automatically when it saves a business
object definition, but you should confirm that the requirement is
met.
There are no requirements regarding the structure of the
business objects for the FixedWidth data handler. The data handler
can process any business object as long as the MaxLength attribute property has a
value.
The business objects that the data handler processes can have
any name allowed by the business integration system.
Business object architecture contains various properties that
apply to attributes. Table 55 describes
how the FixedWidth data handler interprets these properties and
describes how to set the properties when modifying a business
object.
Table 55. Attribute
properties for business objects converted using the FixedWidth data
handler
Property
name |
Description |
Name |
Each business
object attribute must have a unique name. |
Type |
Each business
object attribute must have a type, such as Integer, String, or the
type of a contained child business object. |
Key |
Not used by
the FixedWidth data handler. |
MaxLength
|
Determines
the width of the field in which the attribute value is
included. |
Foreign
Key |
Not used by
the FixedWidth data handler. |
Required |
Not used by
the FixedWidth data handler. |
Default
Value |
Not used by
the FixedWidth data handler. |
Cardinality
|
Supports
cardinality 1 and cardinality n objects. |
The FixedWidth data handler does not require any
application-specific information in business objects or their
attributes. The data handler does, however, check for the existence
of the cw_mo_ tag, which a business object might use to
indicate any child meta-object that the connector uses. The data
handler ignores any attribute identified by the cw_mo_ tag
in the application-specific information of the business object.
The FixedWidth data handler can convert any business object to a
FixedWidth string as long as the business object delivers data in a
form that complies with the requirements of the data handler. The
single requirement of the FixedWidth data handler is that each
business object attribute have a MaxLength value
specified. Existing business objects may need to be modified to
specify an appropriate value for MaxLength.
Although existing business objects that meet this requirement
can be converted by the FixedWidth data handler, a good practice is
to create your own business objects for each type of data to be
processed. If you use a sample business object, or a business
object developed to support the same application in another
implementation, be sure to modify the definition as necessary to
include only the attributes required for the implementation for
which you are developing.
Therefore, to convert existing business objects to a form that
closely corresponds to your data, modify the business object to
provide only the data required by the application and the
information required by the data handler. To adapt existing
business objects for use with the FixedWidth data handler, do the
following:
- Perform a functional analysis of the target application, and
compare the results to existing business objects to determine the
required fields of a business object definition.
- Use Business Object Designer Express to add or delete
attributes from the business object definition as needed.
