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SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
A LSSerializer
provides an API for serializing (writing) a
DOM document out into XML. The XML data is written to a string or an
output stream. Any changes or fixups made during the serialization affect
only the serialized data. The Document
object and its
children are never altered by the serialization operation.
During serialization of XML data, namespace fixup is done as defined in [DOM Level 3 Core]
, Appendix B. [DOM Level 2 Core]
allows empty strings as a real namespace URI. If the
namespaceURI
of a Node
is empty string, the
serialization will treat them as null
, ignoring the prefix
if any.
LSSerializer
accepts any node type for serialization. For
nodes of type Document
or Entity
, well-formed
XML will be created when possible (well-formedness is guaranteed if the
document or entity comes from a parse operation and is unchanged since it
was created). The serialized output for these node types is either as a
XML document or an External XML Entity, respectively, and is acceptable
input for an XML parser. For all other types of nodes the serialized form
is implementation dependent.
Within a Document
, DocumentFragment
, or
Entity
being serialized, Nodes
are processed as
follows
Document
nodes are written, including the XML
declaration (unless the parameter "xml-declaration" is set to
false
) and a DTD subset, if one exists in the DOM. Writing a
Document
node serializes the entire document.
Entity
nodes, when written directly by
LSSerializer.write
, outputs the entity expansion but no
namespace fixup is done. The resulting output will be valid as an
external entity.
true
, EntityReference
nodes are
serialized as an entity reference of the form "
&entityName;
" in the output. Child nodes (the expansion)
of the entity reference are ignored. If the parameter "
entities" is set to false
, only the children of the entity reference
are serialized. EntityReference
nodes with no children (no
corresponding Entity
node or the corresponding
Entity
nodes have no children) are always serialized.
CDATAsections
containing content characters that cannot be
represented in the specified output encoding are handled according to the
"
split-cdata-sections" parameter. If the parameter is set to true
,
CDATAsections
are split, and the unrepresentable characters
are serialized as numeric character references in ordinary content. The
exact position and number of splits is not specified. If the parameter
is set to false
, unrepresentable characters in a
CDATAsection
are reported as
"wf-invalid-character"
errors if the parameter "
well-formed" is set to true
. The error is not recoverable - there is no
mechanism for supplying alternative characters and continuing with the
serialization.
DocumentFragment
nodes are serialized by
serializing the children of the document fragment in the order they
appear in the document fragment.
Note: The serialization of a Node
does not always
generate a well-formed XML document, i.e. a LSParser
might
throw fatal errors when parsing the resulting serialization.
Within the character data of a document (outside of markup), any characters that cannot be represented directly are replaced with character references. Occurrences of '<' and '&' are replaced by the predefined entities < and &. The other predefined entities (>, ', and ") might not be used, except where needed (e.g. using > in cases such as ']]>'). Any characters that cannot be represented directly in the output character encoding are serialized as numeric character references (and since character encoding standards commonly use hexadecimal representations of characters, using the hexadecimal representation when serializing character references is encouraged).
To allow attribute values to contain both single and double quotes, the apostrophe or single-quote character (') may be represented as "'", and the double-quote character (") as """. New line characters and other characters that cannot be represented directly in attribute values in the output character encoding are serialized as a numeric character reference.
Within markup, but outside of attributes, any occurrence of a character
that cannot be represented in the output character encoding is reported
as a DOMError
fatal error. An example would be serializing
the element <LaCañada/> with encoding="us-ascii"
.
This will result with a generation of a DOMError
"wf-invalid-character-in-node-name" (as proposed in "
well-formed").
When requested by setting the parameter "
normalize-characters" on LSSerializer
to true, character normalization is
performed according to the definition of fully
normalized characters included in appendix E of [XML 1.1] on all
data to be serialized, both markup and character data. The character
normalization process affects only the data as it is being written; it
does not alter the DOM's view of the document after serialization has
completed.
Implementations are required to support the encodings "UTF-8",
"UTF-16", "UTF-16BE", and "UTF-16LE" to guarantee that data is
serializable in all encodings that are required to be supported by all
XML parsers. When the encoding is UTF-8, whether or not a byte order mark
is serialized, or if the output is big-endian or little-endian, is
implementation dependent. When the encoding is UTF-16, whether or not the
output is big-endian or little-endian is implementation dependent, but a
Byte Order Mark must be generated for non-character outputs, such as
LSOutput.byteStream
or LSOutput.systemId
. If
the Byte Order Mark is not generated, a "byte-order-mark-needed" warning
is reported. When the encoding is UTF-16LE or UTF-16BE, the output is
big-endian (UTF-16BE) or little-endian (UTF-16LE) and the Byte Order Mark
is not be generated. In all cases, the encoding declaration, if
generated, will correspond to the encoding used during the serialization
(e.g. encoding="UTF-16"
will appear if UTF-16 was
requested).
Namespaces are fixed up during serialization, the serialization process will verify that namespace declarations, namespace prefixes and the namespace URI associated with elements and attributes are consistent. If inconsistencies are found, the serialized form of the document will be altered to remove them. The method used for doing the namespace fixup while serializing a document is the algorithm defined in Appendix B.1, "Namespace normalization", of [DOM Level 3 Core] .
While serializing a document, the parameter "discard-default-content" controls whether or not non-specified data is serialized.
While serializing, errors and warnings are reported to the application
through the error handler (LSSerializer.domConfig
's "
error-handler" parameter). This specification does in no way try to define all possible
errors and warnings that can occur while serializing a DOM node, but some
common error and warning cases are defined. The types (
DOMError.type
) of errors and warnings defined by this
specification are:
"no-output-specified" [fatal]
LSOutput
if no output is specified in the
LSOutput
. "unbound-prefix-in-entity-reference" [fatal]
true
and an entity whose replacement text
contains unbound namespace prefixes is referenced in a location where
there are no bindings for the namespace prefixes. "unsupported-encoding" [fatal]
In addition to raising the defined errors and warnings, implementations are expected to raise implementation specific errors and warnings for any other error and warning cases such as IO errors (file not found, permission denied,...) and so on.
See also the Document Object Model (DOM) Level 3 Load and Save Specification.
Method Summary | |
DOMConfiguration |
getDomConfig()
The DOMConfiguration object used by the
LSSerializer when serializing a DOM node. |
LSSerializerFilter |
getFilter()
When the application provides a filter, the serializer will call out to the filter before serializing each Node. |
java.lang.String |
getNewLine()
The end-of-line sequence of characters to be used in the XML being written out. |
void |
setFilter(LSSerializerFilter filter)
When the application provides a filter, the serializer will call out to the filter before serializing each Node. |
void |
setNewLine(java.lang.String newLine)
The end-of-line sequence of characters to be used in the XML being written out. |
boolean |
write(Node nodeArg,
LSOutput destination)
Serialize the specified node as described above in the general description of the LSSerializer interface. |
java.lang.String |
writeToString(Node nodeArg)
Serialize the specified node as described above in the general description of the LSSerializer interface. |
boolean |
writeToURI(Node nodeArg,
java.lang.String uri)
A convenience method that acts as if LSSerializer.write
was called with a LSOutput with no encoding specified
and LSOutput.systemId set to the uri
argument. |
Method Detail |
public DOMConfiguration getDomConfig()
DOMConfiguration
object used by the
LSSerializer
when serializing a DOM node.
DOMConfiguration
objects for
LSSerializer
adds, or modifies, the following
parameters:
"canonical-form"
true
true
will set the parameters
"format-pretty-print", "discard-default-content", and "xml-declaration
", to false
. Setting one of those parameters to
true
will set this parameter to false
.
Serializing an XML 1.1 document when "canonical-form" is
true
will generate a fatal error. false
"discard-default-content"
true
Attr.specified
attribute to decide what attributes
should be discarded. Note that some implementations might use
whatever information available to the implementation (i.e. XML
schema, DTD, the Attr.specified
attribute, and so on) to
determine what attributes and content to discard if this parameter is
set to true
. false
"format-pretty-print"
true
false
"ignore-unknown-character-denormalizations"
true
"unknown-character-denormalization"
warning (instead of
raising an error, if this parameter is not set) and ignore any
possible denormalizations caused by these characters. false
"normalize-characters"
DOMConfiguration
in [DOM Level 3 Core]
. Unlike in the Core, the default value for this parameter is
true
. While DOM implementations are not required to
support fully
normalizing the characters in the document according to appendix E of [XML 1.1], this
parameter must be activated by default if supported. "xml-declaration"
true
Document
, Element
, or Entity
node is serialized, the XML declaration, or text declaration, should
be included. The version (Document.xmlVersion
if the
document is a Level 3 document and the version is non-null, otherwise
use the value "1.0"), and the output encoding (see
LSSerializer.write
for details on how to find the output
encoding) are specified in the serialized XML declaration. false
"xml-declaration-needed"
warning if this will cause
problems (i.e. the serialized data is of an XML version other than [XML 1.0], or an
encoding would be needed to be able to re-parse the serialized data). public java.lang.String getNewLine()
null
will reset its
value to the default value.
public void setNewLine(java.lang.String newLine)
null
will reset its
value to the default value.
public LSSerializerFilter getFilter()
DOMConfiguration
parameters have been applied. For
example, CDATA sections won't be passed to the filter if "
cdata-sections" is set to false
.public void setFilter(LSSerializerFilter filter)
DOMConfiguration
parameters have been applied. For
example, CDATA sections won't be passed to the filter if "
cdata-sections" is set to false
.public boolean write(Node nodeArg, LSOutput destination) throws LSException
LSSerializer
interface. The output is
written to the supplied LSOutput
.
LSOutput
, the encoding is found by
looking at the encoding information that is reachable through the
LSOutput
and the item to be written (or its owner
document) in this order:
LSOutput.encoding
,
Document.inputEncoding
,
Document.xmlEncoding
.
LSOutput
, a
"no-output-specified" fatal error is raised.
nodeArg
- The node to serialize.destination
- The destination for the serialized DOM.true
if node
was
successfully serialized. Return false
in case the
normal processing stopped but the implementation kept serializing
the document; the result of the serialization being implementation
dependent then.LSException
- SERIALIZE_ERR: Raised if the LSSerializer
was unable to
serialize the node. DOM applications should attach a
DOMErrorHandler
using the parameter "
error-handler" if they wish to get details on the error.public boolean writeToURI(Node nodeArg, java.lang.String uri) throws LSException
LSSerializer.write
was called with a LSOutput
with no encoding specified
and LSOutput.systemId
set to the uri
argument.nodeArg
- The node to serialize.uri
- The URI to write to.true
if node
was
successfully serialized. Return false
in case the
normal processing stopped but the implementation kept serializing
the document; the result of the serialization being implementation
dependent then.LSException
- SERIALIZE_ERR: Raised if the LSSerializer
was unable to
serialize the node. DOM applications should attach a
DOMErrorHandler
using the parameter "
error-handler" if they wish to get details on the error.public java.lang.String writeToString(Node nodeArg) throws DOMException, LSException
LSSerializer
interface. The output is
written to a DOMString
that is returned to the caller.
The encoding used is the encoding of the DOMString
type,
i.e. UTF-16. Note that no Byte Order Mark is generated in a
DOMString
object.nodeArg
- The node to serialize.DOMException
- DOMSTRING_SIZE_ERR: Raised if the resulting string is too long to
fit in a DOMString
.LSException
- SERIALIZE_ERR: Raised if the LSSerializer
was unable to
serialize the node. DOM applications should attach a
DOMErrorHandler
using the parameter "
error-handler" if they wish to get details on the error.
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