CURSORTOXML( ) Function

Converts a Visual FoxPro cursor to XML.

CURSORTOXML(nWorkArea | cTableAlias, cOutput [, nOutputFormat 
[, nFlags [, nRecords [, cSchemaName [, cSchemaLocation [, cNameSpace ]]]]]])

Parameters

• nWorkArea
  Specifies the work area of the table from which to create the XML string.

  If you specify 0 or no value, Visual FoxPro uses the current work area.

• cTableAlias
  Specifies the alias of the table from which to create the XML string.

• cOutput
  Specifies the path and file name or memory variable name to which results are sent.

  If nFlags is set to 0 (default) for memory variable output, XML is returned to the memory variable. If the memory variable does not exist, it is created.

  If nFlags is set to 512 for file output, and the file does not exist, it is created. If the file already exists, it is overwritten. The setting for SET SAFETY is observed.

• nOutputFormat
  Specifies the output format of the XML string. The following table lists the values for nOutputFormat.

  nOuputFormat	Description
  1 – ELEMENTS	(Default) Element-centric XML
  2 – ATTRIBUTES	Attribute-centric XML
  3 – RAW	Generic, attribute-centric XML

• nFlags
  Specifies the formatting of the XML that is produced and its destination. The following table lists the values for nFlags.

  nFlags	Bit	Output description
  0	0000	(Default) Produce XML in UTF-8 format. This setting creates a memory variable if one does not exist when specified by cOutput and returns XML to the memory variable. The XML declaration does not contain an Encoding= attribute; that is, no encoding attribute is set to UTF-8.
  1	0001	Produce unformatted XML as a continuous string.
  2	0010	Enclose empty elements with open and closing elements, for example, <cc04><cc04/>.
  4	0100	Preserve white space in fields.
  8	1000	Wrap Memo fields in CDATA sections.
  16	10000	Output encoding. Output is set to the cursor code page. To ensure accurate character translation, the Visual FoxPro default code page must match the code page of the cursor. You can accomplish this by setting character and memo fields in the cursor to NOCPTRAN (character binary/memo binary). When setting this value with tables using any of the code pages, the encoding attribute in the XML is set to an empty string (""). To change to the correct encoding attribute, use the STRTRAN( ) function. For example, for code page 936, provide the following to the resulting XML string: strxml=STRTRAN(strxml, 'encoding=""', 'encoding="gb2312"'
  32	100000	Output encoding.
  512	1000000000	Output to the file specified by cOutput. If a file does not exist, it is created. If the file already exists, it is overwritten. The setting for SET SAFETY is observed.
  4096	1000000000000	Disables base64 encoding. CURSORTOXML( ) exports Memo (Binary) fields as xsd:base64binary unless you use nFlags set to 4096. In Visual FoxPro, base64 encoding is meant for encoding only binary data.
  32768	none	Indicates that a code page should be used.

  The following table describes how the encoding attribute is written when output encoding defaults to the cursor or table code page.

  Note

  Encoding flags are set by combining bits 4 and 5 (0010000).

  Encoding flag	Bits 4 and 5	Description
  +0	00	(Default) Windows-1252.
  +16	01	Set output encoding attribute to the cursor code page.
  +32	10	Set output encoding attribute to UTF-8 with no character translation.
  +48	11	Set output encoding attribute to UTF-8 and translate character data to UTF-8.

  The following table lists common Windows-compatible code pages.

  Code page	Platform	Encoding attribute in XML Declaration	Comments
  437	MS-DOS, US	ibm437
  850	MS-DOS, International	ibm850
  865	MS-DOS, Nordic	Empty string ("")
  866	MS-DOS, Russian	cp866
  932	Windows, Japanese	shift-jis
  936	Simplified Chinese	gb2312
  949	Windows, Korean	iso-2022-kr	or: ks_c_5601-1987
  950	Windows, Traditional Chinese (Taiwan)	big5
  1250	Windows, East European	Windows-1250	Note case.
  1251	Windows, Russian	Windows-1251
  1252	Windows, U.S., West European	Windows-1252
  1253	Windows, Greek	Windows-1253
  1254	Windows, Turkish	Windows-1254
  1255	Windows, Hebrew	Windows-1255
  1256	Windows, Arabic	Windows-1256

  Note

  Visual FoxPro uses Windows-1252 as the default encoding. You can specify that the encoding attribute be set to match the code page, such as Big5 (code page 950), when using double-byte character sets (DBCS) for DBCS languages for which Visual FoxPro supports code pages.

  When using Windows-1252 and DBCS, no additional character translation is required to display correctly in Internet Explorer.

  However, to make XML more compliant for Web browsers that can interpret UTF-8, you can optionally set the encoding attribute to UTF-8 instead of Windows-1252. The result set undergoes translation to UTF-8 characters only when you set nFlags to 48 (specify the encoding attribute as UTF-8 and translate character data to UTF-8 format). This is required only when the data actually contains double-byte characters. You do not have to use character translation, STRCONV ( ), for example, if you are outputting only Latin (single byte) characters.

• nRecords
  Specifies the number of records to output to XML and has a default value is 0.

  If nRecords is 0, all records are output. If nRecords is greater than the number of records remaining in the table, all remaining records are output.

• cSchemaName
  Specifies the name and location to contain schema information for the data in cOutput, for example "MySchema.xsd". If no extension is provided, the schema file is created with an .xsd extension.

  The following table lists the values for cSchemaName.

  cSchemaName	Description
  cSchemaName	Specifies the name and path of the external file for the schema (scoped to the root element of the XML). Note If cSchemaName contains a file name and cSchemaLocation is not provided or is blank, the contents of cSchemaName are written to the xsi:schemaLocation or xsi:noNamespaceSchemaLocation attribute in the XML. In the following example, Visual FoxPro generates a generic XML file named MyXMLFile.xml from the Labels.dbf file in the "Labels" alias and the schema file named MySchema in the same folder. CURSORTOXML("LABELS", "myXMLFile.xml", 1, 512, 0, "mySchema.xsd") If cSchemaName includes a URI, the schema is written to the current directory and must be uploaded to the server to be accessed by the browser or parser. External schemas always are written to the same location as the XML file.
  "1"	Specifies an inline schema is produced. For example, the following code produces an inline schema: CURSORTOXML("LABELS", "myXMLFile.xml", 1, 512, 0, "1")
  ""	Specifies that no schema is produced.

• cSchemaLocation
  Specifies an optional location where the application reading the XML data should look for the schema file.

  Note

  Use this parameter only when you are deploying your schema to a location other than the location of the XML data.

  The contents of cSchemaLocation are written to the xsi:schemaLocation or xsi:noNamespaceSchemaLocation attribute of the XML data produced. The cschemaLocation parameter can be an HTTP address or other URI. You need to copy the schema file to the location you have specified in cSchemaLocation.

  The following example produces XML data:

     CURSORTOXML("LABELS", "myXMLFile.xml", 1, 512, 0, ;
         "mySchema.xsd", "https://www.microsoft.com/mySchema.xsd")
  

  containing the following attribute:

     xsi:noNamespaceSchemaLocation=" https://www.microsoft.com/mySchema.xsd"
  

  Specifying cSchemaLocation when cSchemaName is blank causes the same attributes to be written to the XML data. This makes it possible for you to point to an existing schema without recreating the schema each time CURSORTOXML( ) is called.

• cNamespace
  Specifies the namespace of the XML or schema to be produced and has an empty string ("") as the default value.

  Specifying a value for cNameSpace sets the targetNamespace attribute to the same value and adds the elementFormDefault="qualified" attribute to the schema.

  If you do not specify a cNamespace value, and the schema is external, no namespace declaration is written to the schema. If you do not specify a cNamespace value and the schema is inline, the targetNamespace in the schema is set to an empty string ("").

Return Value

Numeric data type. CURSORTOXML( ) returns the number of bytes written to the file or a memory variable.

Remarks

You can use CURSORTOXML( ) with the OLE DB Provider for Visual FoxPro. However, the _VFP VFPXMLProgID property is not supported because the _VFP system variable is not supported in the OLE DB Provider.

CURSORTOXML( ) output adheres to the cursor index order, SET FIELDS TO, and current filter settings. However, it does not preserve the cursor location. After the calling CURSORTOXML( ), if all records are output, the cursor record pointer reports EOF. If not all records are output, it points to the last record output to XML.

The resulting XML from CURSORTOXML( ) contains the same scale as the exported table if the table contains Double data type values. For example, if a Double column is created with a scale of 6 using the following codem the resulting XML contains six digits to the right of the decimal point:

CREATE TABLE test (col1 b(6))

When you use the CURSORTOXML( ) function to export a table or cursor to XML, the root node is always called "VFPData", regardless of the output format.

For Date types only, you can export "EMPTY" Date and DateTime types using CURSORTOXML( ). However, the XML schema validation might fail because "EMPTY" is not valid for these types in an XML schema definition (XSD) schema. This is an issue only if a schema is required, and the resulting XML is validated against an XML parser that can interpret XSD schemas. To work around this issue, you might need to change the data to a nonempty representation by calling the appropriate SELECT statement and use CURSORTOXML( ) on the created cursor. For example, you can change the empty Date or DateTime values to .NULL.:

SELECT orderid, EVL(shippeddate,.NULL.) as ShippedDate FROM orders

You can also change the empty Date or DateTime to an appropriate representation for "empty":

SELECT orderid, IIF(EMPTY(shippeddate),{^1899-12-30 00:00:00},tc11); 
   as ShippedDate FROM orders

When using flag 32768, the flags 16 and 32 settings can affect which code page is applied depending on the type of data you are writing to XML. The following tables show the possible combinations of settings and the code page each combination applies.

For XML documents written with the 32768 flag set, the following code pages are applied.

For XML documents written without setting the 32768 flag, the following code pages are applied.

See Also

Reference

XMLUPDATEGRAM( ) Function
XMLTOCURSOR( ) Function

Concepts

Converting Between XML and Visual FoxPro Data
XML Data in Visual FoxPro

Other Resources

Functions