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Schema Interface

Table 7-1 summarizes the methods of available through the Schema interface.

Table 7-1 Summary of Schema Methods

Function	Summary
XmlSchemaClean	Clean up loaded schemas in a schema context and recycle the schema context.
XmlSchemaCreate	Create and return a schema context.
XmlSchemaDestroy	Destroy a schema context.
XmlSchemaErrorWhere	Returns the location where an error occurred.
XmlSchemaLoad	Load a schema document.
XmlSchemaLoadedList	Return the size and/or list of loaded schema documents.
XmlSchemaSetErrorHandler	Sets an error message handler and its associated context in a schema context
XmlSchemaSetValidateOptions	Set option(s) to be used in the next validation session.
XmlSchemaTargetNamespace	Return target namespace of a given schema document.
XmlSchemaUnload	Unload a schema document.
XmlSchemaValidate	Validate an element node against a schema.
XmlSchemaVersion	Return the version of this schema implementation.

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XmlSchemaClean

Clean up loaded schemas in a schema context and recycle the schema context.

Syntax

void XmlSchemaClean(
   xsdctx *sctx);

Parameter	In/Out	Description
sctx	IN	schema context to be cleaned

See Also: XmlSchemaCreate, XmlSchemaDestroy

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XmlSchemaCreate

Return a schema context to be used in other validator APIs. This needs to be paired with an XmlSchemaDestroy.

Syntax

xsdctx *XmlSchemaCreate(
   xmlctx *xctx, 
   xmlerr *err, 
   list);

Parameter	In/Out	Description
xctx	IN	XML context
err	OUT	returned error code
list	IN	NULL-terminated list of variable arguments

Returns

(xsdctx *) schema context

See Also: XmlSchemaDestroy, XmlCreate in Chapter 9, " Package XML APIs for C"

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XmlSchemaDestroy

Destroy a schema context and free up all its resources.

Syntax

void XmlSchemaDestroy(
   xsdctx *sctx);

Parameter	In/Out	Description
sctx	IN	schema context to be freed

See Also: XmlSchemaCreate

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XmlSchemaErrorWhere

Returns the location (line#, path) where an error occurred.

Syntax

xmlerr XmlSchemaErrorWhere(
   xsdctx *sctx, 
   ub4 *line, 
   oratext **path);

Parameter	In/Out	Description
sctx	IN	schema context
line	IN/OUT	line number where error occurred
path	IN/OUT	URL or filespace where error occurred

Returns

(xmlerr) error code

See Also: XmlSchemaSetErrorHandler

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XmlSchemaLoad

Load up a schema document to be used in the next validation session. Schema documents can be incrementally loaded into a schema context as long as every loaded schema document is valid. When the last loaded schema turns out to be invalid, you need to clean up the schema context by calling XmlSchemaClean and reload everything all over again including the last schema with appropriate correction.

Syntax

xmlerr XmlSchemaLoad(
   xsdctx *sctx, 
   oratext *uri, 
   list);

Parameter	In/Out	Description
sxctx	IN	schema context
uri	IN	URL of schema document; compiler encoding
list	IN	NULL-terminated list of variable arguments

Returns

(xmlerr) numeric error code, XMLERR_OK [0] on success

See Also: XmlSchemaUnload, XmlSchemaLoadedList

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XmlSchemaLoadedList

Return only the size of loaded schema documents if list is NULL. If list is not NULL, a list of URL pointers are returned in the user-provided pointer buffer. Note that its user's responsibility to provide a buffer with big enough size.

Syntax

ub4 XmlSchemaLoadedList(
   xsdctx *sctx, 
   oratext **list);

Parameter	In/Out	Description
sctx	IN	schema context
list	IN	address of pointer buffer

Returns

(ub4) list size

See Also: XmlSchemaLoad, XmlSchemaUnload

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XmlSchemaSetErrorHandler

Sets an error message handler and its associated context in a schema context. To retrieve useful location information on errors, the address of the schema context must be provided in the error handler context.

Syntax

xmlerr XmlSchemaSetErrorHandler(
   xsdctx *sctx, 
   XML_ERRMSG_F(
      (*errhdl), 
      ectx, 
      msg, 
      err), 
   void *errctx);

Parameter	In/Out	Description
sctx	IN	schema context
errhdl	IN	error message handler
errctx	IN	error handler context

Returns

(xmlerr) error code

See Also: XmlSchemaCreate, XmlSchemaErrorWhere, and XML_ERRMSG_F in Chapter 3, " Package Callback APIs for C"

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XmlSchemaSetValidateOptions

Set options to be used in the next validation session. Previously set options will remain effective until they are overwritten or reset.

Syntax

xmlerr XmlSchemaSetValidateOptions(
   xsdctx *sctx, 
   list);

Parameter	In/Out	Description
sctx	IN	schema context
list	IN	NULL-terminated list of variable argument

Returns

(xmlerr) numeric error code, XMLERR_OK [0] on success

See Also: XmlSchemaValidate

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XmlSchemaTargetNamespace

Return target namespace of a given schema document identified by its URI. All currently loaded schema documents can be queried. Currently loaded schema documents include the ones loaded through XmlSchemaLoads and the ones loaded through schemaLocation or noNamespaceSchemaLocation hints.

Syntax

oratext *XmlSchemaTargetNamespace(
   xsdctx *sctx, 
   oratext *uri);

Parameter	In/Out	Description
sctx	IN	XML context
uri	IN	URL of the schema document to be queried

Returns

(oratext *) target namespace string; NULL if given document not

See Also: XmlSchemaLoadedList

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XmlSchemaUnload

Unload a schema document from the validator. All previously loaded schema documents will remain loaded until they are unloaded. To unload all loaded schema documents, set URI to be NULL (this is equivalent to XmlSchemaClean). Note that all children schemas associated with the given schema are also unloaded. In this implementation, it only support the following scenarios:

• load, load, ...

• load, load, load, unload, unload, unload, clean, and then repeat.

It doesn't not support: load, load, unload, load, ....

Syntax

xmlerr XmlSchemaUnload(
   xsdctx *sctx, 
   oratext *uri, 
   list);

Parameter	In/Out	Description
sctx	IN	schema context
uri	IN	URL of the schema document; compiler encoding
list	IN	NULL-terminated list of variable argument

Returns

(xmlerr) numeric error code, XMLERR_OK [0] on success

See Also: XmlSchemaLoad, XmlSchemaLoadedList

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XmlSchemaValidate

Validates an element node against a schema. Schemas used in current session consists of all schema documents specified through XmlSchemaLoad and provided as hint(s) through schemaLocation or noNamespaceSchemaLocation in the instance document. After the invocation of this routine, all loaded schema documents remain loaded and can be queried by XmlSchemaLoadedList. However, they will remain inactive. In the next validation session, inactive schema documents can be activated by specifying them through XmlSchemaLoad or providing them as hint(s) through schemaLocation or noNamespaceSchemaLocation in the new instance document. To unload a schema document and all its descendants (documents included or imported in a nested manner), use XmlSchemaUnload.

Syntax

xmlerr XmlSchemaValidate(
   xsdctx *sctx,
   xmlctx *xctx, 
   xmlelemnode *elem);

Parameter	In/Out	Description
sctx	IN	schema context
xctx	IN	XML top-level context
elem	IN	element node in the doc, to be validated

Returns

(xmlerr) numeric error code, XMLERR_OK [0] on success

See Also: XmlSchemaSetValidateOptions

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XmlSchemaVersion

Return the version of this schema implementation.

Syntax

oratext *XmlSchemaVersion();

Returns

(oratext *) version string [compiler encoding]