Editing XML templates

Using templates for data import If you use a template created for data export, DataWindow expressions,
text, comments, and processing instructions are
ignored when data is imported. If you are creating a template specifically
for import, do not add any of these items. You need only map column
names to element and attribute names.

Every item in
the Export/Import Template view has a pop-up menu from
which you can perform actions appropriate to that item, such as
editing or deleting the item, adding or editing attributes, adding
child elements or other items, and inserting elements, processing
instructions, CDATA sections, and so forth, before the current item.

If an element has no attributes, you can edit its tag in the
Export/Import Template view by selecting it and left-clicking
the tag or pressing F2. Literal text nodes can be edited in the
same way. You can delete items (and their children) by pressing
the Delete key.

The examples in this section show the delimiters used in the
XML document. When you edit the template in dialog boxes opened
from the Export/Import Template view for XML, you do not
need to type these delimiters in text boxes.

The rest of this section describes some of the items in the
template. For more information, see the XML specification
.

XML declaration

The XML declaration specifies the version of XML being used.
You may need to change this value for a future version of XML. It
can also contain an encoding declaration and a standalone document
declaration. From the pop-up menu, you can edit the declaration,
and, if the document is well-formed, delete it. If you have deleted
the XML declaration, you can insert one from the Insert Before item
on the pop-up menu for the next item in the template.

Encoding declaration

The encoding declaration specifies the character-set encoding
used in the document, such as UTF-16 or ISO-10646-UCS-4.

If there is no encoding declaration, the value defaults to
UTF-8 encoding in ASCII environments. In DBCS environments, the
default is the default system encoding on the computer where the
XML document is generated. This ensures that the document displays
correctly as a plain text file. However, since the DBCS data is
serialized to Unicode, XML documents that use UTF-8, UTF-16 Big
Endian, or UTF-16 Little Endian can all be parsed or generated correctly on
DBCS systems.

Several other encodings are available, including ASCII, UCS4
Big Endian, UCS4 Little Endian, EBCDIC code pages IBM037 and IBM1140,
ISO Latin-1, and Latin 1 Windows (code page 1252). You
can select these values from a drop-down list box in the XML Declaration
dialog box.

Standalone document declaration

The standalone document declaration specifies whether the
document contains no external markup that needs to be processed
and can therefore stand alone (Yes), or that there are, or might
be, external markup declarations in the document (No). The value
in the default template is No, and if there is no standalone document
declaration, the value is assumed to be No.

Example

This is an XML declaration that specifies XML version 1.0,
UTF-8 encoding, and that the document can stand alone:

Document type declaration

The document type declaration contains or points to markup
declarations that provide a grammar for a class of documents. This
grammar is known as a document type definition, or DTD. The document
type declaration defines constraints on the sequence and nesting
of tags, attribute values, names and formats of external references,
and so forth. You
can edit the document type declaration to change its name, but the
name must always be the same as the name of the root element. Changing
the name in the document type declaration or the root element automatically
changes the name in the other.

Adding DTDs

You can add an identifier pointing to an external DTD subset,
and you can add an internal DTD subset. If you supply both external
and internal subsets, entity and attribute-list declarations in
the internal subset take precedence over those in the external subset.

Public identifiers

An external identifier can include a public identifier that
can be used by an XML processor to generate an alternative URI.
If an alternative URI cannot be generated, the URI provided in the
system identifier is used. External identifiers without a public
identifier are preceded by the keyword SYSTEM. External
identifiers with a public identifier are preceded by the keyword PUBLIC.

Exporting metadata If you specify a system or public identifier and/or
an internal subset in the Document Type Declaration dialog box,
a DTD cannot be generated when the data is exported to XML. A MetaDataType
of XMLDTD! is ignored. For more information about the properties
that control the export of metadata, see “Exporting metadata”.

Examples

These are examples of valid document type declarations.

An external system identifier:

An external system identifier with a public identifier:

An external system identifier with an internal DTD. The internal
DTD is enclosed in square brackets:

Root element

You can change the name of the root element, add attributes
and children, and insert comments, instructions, and, if they do
not already exist, XML and/or document type declarations
before it.

Changing the name of the root element changes the name of
its start and end tags. You can change the name using the Edit menu
item, or in the Element Attributes dialog box. Changing the name
of the document type declaration, if it exists, also changes the
name of the root element, and vice versa. The root element name
is always the same as the document type declaration name.

You can add the following kinds of children to the root element:

• Elements
• Text
• Control references
• DataWindow expressions (including column references)
• CDATA sections
• Comments
• Processing instructions

Controls

Adding a DataWindow control reference opens a dialog box containing
a list of the columns, computed fields, report controls, and text
controls in the document.

Control references can also be added to empty attribute values
or element contents using drag-and-drop from the Control List view.
Column references can also be added using drag-and-drop from the
Column Specifications view.

Drag-and-drop cannot replace You cannot drag-and-drop an item on top of another item to
replace it. For example, if you want to replace one control reference
with another control reference, or with a DataWindow expression, you first
need to delete the control reference you want to replace.

DataWindow expressions

Adding a DataWindow expression opens the Modify Expression dialog box. This
enables you to create references to columns from the data source
of the DataWindow object. It also enables the calling of global functions.
One use of this feature is to return a fragment of XML to embed,
providing another level of dynamic XML generation.

Using Date and DateTime with strings

If you use a control reference or a DataWindow expression that does not include
a string to represent Date and DateTime columns in a template, the XML
output conforms to ISO 8601 date and time formats. For example, consider
a date that displays as 12/27/2002 in
the DataWindow, using the display format mm/dd/yyyy.
If the export template does not use an expression that includes
a string, the date is exported to XML as 2002-12-27.

However, if the export template uses an expression that combines
a column with a Date or DateTime datatype with a string, the entire
expression is exported as a string and the regional settings in
the Windows registry are used to format the date and time.

Using the previous example, if the short date format in the
registry is MM/dd/yy,
and the DataWindow expression is: “Start Date is ” + start_date,
the XML output is Start Date is 12/27/02.

Attributes

Controls or expressions can also be referenced for element
attribute values. Select Edit/Add Attribute from the pop-up
menu for elements to edit an existing attribute or add a new one.

For each attribute specified, you can select a control reference
from the drop-down list or enter a literal text value.
A literal text value takes precedence over a control reference.
You can also use the expression button to the right of the Text
box to enter an expression.

The expression button and entry operates similarly to DataWindow object properties
in the Properties view. The button shows a green equals sign if
an expression has been entered, and a red not-equals sign if not.
A control reference or text value specified in addition to the expression
is treated as a default value. In the template, this combination
is stored with the control reference or text value, followed by
a tab, preceding the expression. For example:

Composite and nested reports

Report controls can be referenced in the Detail section of
export templates as children of an element.

Nested reports supported for XML export only Import does not support nested reports. If you attempt to
import data in any format, including XML, CSV, DBF, and TXT, that
contains a nested report, the nested report is not imported and
the import may fail with errors.

Composite reports

For composite reports that use the Composite presentation
style, the default template has elements that reference each of
its nested reports.

If a composite DataWindow contains two reports that have columns
with identical names, you must use the procedure that follows if
you want to generate an XML document with a DTD or schema. If you
do not follow the procedure, you will receive a parsing error such
as “Element ‘identical_column_name‘ has
already been declared.”

1. Create
   a template in the first report and select this template in the Use Template
   list on the Data Export property page.
2. Create a template in the second report.
3. If any element name is used in the template in the
   first report, change it to another name in the template in the second
   report.
4. Select the template for the second report in the
   Use Template list.
5. Generate the XML document.

These steps are necessary because you cannot use a given element
name more than once in a valid DTD or schema.

Nested reports

For report controls added to the detail band of a base report
that is related to the inserted report with retrieval arguments
or criteria, the report control is available to the export template
in two ways:

• Select an element in the template
  or add a new element, then select Add Child>DataWindow
  Control Reference. Any report controls inserted in the detail band
  are available for selection in the dialog box that displays.
• Drag a report control from the Control List view
  and drop it on an existing empty element.

When you export XML using a template that has a reference
to a report control, the export template assigned to the nested
report with the Use Template property is used, if it exists, to
expand the XML for the nested report. If no template is specified
for the nested report, the default template is used.

The relationship between the nested report and the base report,
for example a Master/Detail relationship, is reflected
in the exported XML.

CDATA sections

You can export the name of a column in a CDATA section using the syntax <![CDATA[columnname]]>. You can export the value of a column using the syntax <![CDATA[~t columnname]]>. The ~t is used to introduce a DataWindow expression, in the same way that it is used in the Modify method. You can also use an expression such as ~t columnname*columnname to export a computed value to the XML.

You can import a value into a column using the syntax <![CDATA[columnname]]>. Note that this syntax in a template has different results for import and export: it imports the column value but exports the column name.

You cannot import an XML file that has a ~t expression in a CDATA section.

Everything else inside a CDATA section is ignored by the parser.
If text contains characters such as less than or greater than signs
(< or >) or ampersands (&) that are significant
to the parser, it should be defined as a CDATA section. A CDATA
section starts with <![CDATA[ and
ends with ]]>.
CDATA sections cannot be nested, and there can be no white space
characters inside the ]]> delimiter–for
example, you cannot put a space between the two square brackets.

Example

This syntax in an export template exports the value of the column emp_salary:

This syntax in an import template imports the value of the column emp_salary:

Comments

Comments can appear anywhere in a document outside other markup.
They can also appear within the document type declaration in specific
locations defined by the XML specification.

Comments begin with <!– and
end with –>. You
cannot use the string — (a
double hyphen) in a comment, and parameter entity references are
not recognized in comments.

Example

Processing instructions

Processing instructions (PIs) enable you to provide information
to the application that uses the processed XML. Processing instructions
are enclosed in <? and ?> delimiters
and must have a name, called the target, followed by optional data
that is processed by the application that uses the XML. Each application
that uses the XML must process the targets that it recognizes and ignore
any other targets.

The XML declaration at
the beginning of an XML document is an example of a processing instruction.
You cannot use the string xml as
the name of any other processing instruction target.

Example

In this example, usething is
the name of the target, and thing=this.thing is
the data to be processed by the receiving application:

---