Difference between revisions of "Serialization"

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This page is part of the [[XQuery|XQuery Portal]].
 
This page is part of the [[XQuery|XQuery Portal]].
Serialization parameters define how XQuery items and XML nodes are textually output, i.e., ''serialized''. (For input, see [[Parsers]].)
 
They have been formalized in the [http://www.w3.org/TR/xslt-xquery-serialization-30 W3C XQuery Serialization 3.0] document.
 
In BaseX, they can be specified in several ways:
 
  
* by including them in the [[XQuery_3.0#Serialization|prolog of the XQuery expression]],
+
Serialization parameters define how XQuery items and XML nodes will be ''serialized'' (i.e., returned to the client or an API, usually in textual form). The official parameters are defined in the [https://www.w3.org/TR/xslt-xquery-serialization-31 W3C XQuery Serialization 3.1] document. In BaseX, they can be:
* by specifying them in the XQuery functions [[File_Module#file:write|file:write()]] or [[XQuery_3.0#Functions|fn:serialize()]],
+
 
* by using the {{Code|-s}} flag of the BaseX [[Startup_Options#BaseX|command-line]] clients,
+
* included in the [[XQuery_3.0#Serialization|prolog of the XQuery expression]];
* by setting the [[Options#SERIALIZER|SERIALIZER]] option before running a query,
+
* specified in XQuery functions ({{Function|File|file:write}}, {{Function|Database|db:export}}, [https://www.w3.org/TR/xpath-functions-31/#func-serialize fn:serialize()]);
* by setting the [[Options#EXPORTER|EXPORTER]] option before exporting a database, or
+
* specified in [[REST#Parameters|REST query parameters]];
* by setting them as [[REST#Query_Parameters|REST]] query parameters<br/><br/>
+
* specified in [[RESTXQ#Output|RESTXQ output annotations]];
 +
* set via the {{Option|SERIALIZER}} option before running a query;
 +
* set via the {{Option|EXPORTER}} option before exporting a database; or
 +
* supplied with the {{Code|-s}} flag of the BaseX [[Command-Line Options#BaseX Standalone|command-line]] clients.
 +
 
 +
The namespace for serialization parameters is statically bound to the {{Code|output}} prefix. This means that it need not (but may) be declared in the query prolog:
 +
 
 +
<syntaxhighlight lang="xquery">
 +
declare namespace output = 'http://www.w3.org/2010/xslt-xquery-serialization';
 +
declare option output:method 'text';
 +
<xml>Hi there</xml>
 +
</syntaxhighlight>
 +
 
 +
Due to the wide range of ways how parameters can be supplied, we deliberately ignored one rule of the specification, which requires non-official features to be defined in a non-null namespace URI. In the following, we will indicate which features are specific to our implementation.
  
 
=Parameters=
 
=Parameters=
  
The following table gives a brief summary of all serialization parameters recognized by BaseX. For details, please refer to official specification.
+
The following serialization parameters are supported by BaseX (further details can be looked up in the official specification):
  
 
{| class="wikitable sortable" width="100%"
 
{| class="wikitable sortable" width="100%"
 
|- valign="top"
 
|- valign="top"
! Parameter
+
! width="140" | Parameter
 
! Description
 
! Description
 
! Allowed
 
! Allowed
 
! Default
 
! Default
! Examples
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|method}}
 
| {{Code|method}}
| Specifies the serialization method:
+
| Specifies the serialization method. {{Code|xml}}, {{Code|xhtml}}, {{Code|html}}, {{Code|text}} and {{Code|adaptive}} are part of the official specification. For more details on {{Code|basex}}, {{Code|csv}} and {{Code|json}}, see [[XQuery Extensions#Serialization|XQuery Extensions]].
* {{Code|xml}}, {{Code|xhtml}}, {{Code|html}}, and {{Code|text}} are adopted from the official specification.
+
| {{Code|xml}}, {{Code|xhtml}}, {{Code|html}}, {{Code|text}}, {{Code|json}}, {{Code|adaptive}}, {{Code|csv}}, {{Code|basex}}
* {{Code|json}} and {{Code|jsonml}} are specific to BaseX and can be used to output XML nodes in the JSON format (see the [[JSON Module]] for more details).
+
| {{Code|basex}}
* {{Code|raw}} is BaseX-specific as well: Binary data types are output in their ''raw'' form, i.e., without modifications. For all other types, the items’ string values are returned. No indentation takes place, and and no characters are encoded via entities.
 
| {{Code|xml}}, {{Code|xhtml}}, {{Code|html}}, {{Code|text}}, {{Code|json}}, {{Code|jsonml}}, {{Code|raw}}
 
| {{Code|xml}}
 
| <code>method=xml</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|version}}
 
| {{Code|version}}
 
| Specifies the version of the serialization method.
 
| Specifies the version of the serialization method.
| {{Code|xml/xhtml}}: {{Code|1.0}}, {{Code|1.1}}<br/>{{Code|html}}: {{Code|4.0}}, {{Code|4.01}}, {{Code|5.0}}<br/>
+
| xml/xhtml: {{Code|1.0}}, {{Code|1.1}}<br/>html: {{Code|4.0}}, {{Code|4.01}}, {{Code|5.0}}<br/>
 
| {{Code|1.0}}
 
| {{Code|1.0}}
| <code>version=1.0</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|html-version}}
 
| {{Code|html-version}}
Line 42: Line 46:
 
| {{Code|4.0}}, {{Code|4.01}}, {{Code|5.0}}
 
| {{Code|4.0}}, {{Code|4.01}}, {{Code|5.0}}
 
| {{Code|4.0}}
 
| {{Code|4.0}}
| <code>html-version=5.0</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|item-separator}}
 
| {{Code|item-separator}}
 
| Determines a string to be used as item separator. If a separator is specified, the default separation of atomic values with single whitespaces will be skipped.
 
| Determines a string to be used as item separator. If a separator is specified, the default separation of atomic values with single whitespaces will be skipped.
| ''arbitrary strings'', {{Code|\n}}, {{Code|\r\n}}, {{Code|\r}}
+
| ''string''
| ''empty''
+
|
| <code>item-separator=&#a;</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|encoding}}
 
| {{Code|encoding}}
 
| Encoding to be used for outputting the data.
 
| Encoding to be used for outputting the data.
| ''[http://docs.oracle.com/javase/7/docs/technotes/guides/intl/encoding.doc.html all encodings supported by Java]''
+
| ''[https://docs.oracle.com/javase/8/docs/technotes/guides/intl/encoding.doc.html all encodings supported by Java]''
 
| {{Code|UTF-8}}
 
| {{Code|UTF-8}}
| <code>encoding=US-ASCII</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|indent}}
 
| {{Code|indent}}
Line 60: Line 61:
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}
 
| {{Code|yes}}
| <code>indent=no</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|cdata-section-elements}}
 
| {{Code|cdata-section-elements}}
 
| List of elements to be output as CDATA, separated by whitespaces.<br />Example: {{Code|&lt;text&gt;&lt;![CDATA[ &lt;&gt; ]]&gt;&lt;/text&gt;}}
 
| List of elements to be output as CDATA, separated by whitespaces.<br />Example: {{Code|&lt;text&gt;&lt;![CDATA[ &lt;&gt; ]]&gt;&lt;/text&gt;}}
 +
| ''string''
 
|  
 
|  
|
 
| <code>cdata-section-elements=text</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|omit-xml-declaration}}
 
| {{Code|omit-xml-declaration}}
Line 72: Line 71:
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}
 
| {{Code|yes}}
| <code>omit-xml-declaration=no</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|standalone}}
 
| {{Code|standalone}}
Line 78: Line 76:
 
| {{Code|yes}}, {{Code|no}}, {{Code|omit}}
 
| {{Code|yes}}, {{Code|no}}, {{Code|omit}}
 
| {{Code|omit}}
 
| {{Code|omit}}
| <code>standalone=yes</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|doctype-system}}
 
| {{Code|doctype-system}}
 
| Introduces the output with a document type declaration and the given system identifier.<br />Example: {{Code|&lt;!DOCTYPE x SYSTEM "entities.dtd"&gt;}}
 
| Introduces the output with a document type declaration and the given system identifier.<br />Example: {{Code|&lt;!DOCTYPE x SYSTEM "entities.dtd"&gt;}}
 +
| ''string''
 
|
 
|
|
 
| <code>doctype-system=entities.dtd</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|doctype-public}}
 
| {{Code|doctype-public}}
 
| If {{Code|doctype-system}} is specified, adds a public identifier.<br />Example: {{Code|&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "<nowiki>http://www.w3.org/TR/html4/strict.dtd</nowiki>"&gt;}}
 
| If {{Code|doctype-system}} is specified, adds a public identifier.<br />Example: {{Code|&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "<nowiki>http://www.w3.org/TR/html4/strict.dtd</nowiki>"&gt;}}
|  
+
| ''string''
 
|
 
|
| <code>doctype-public=-//W3C//DTD HTML 4.01//EN,<br />doctype-system=http://www.w3.org/TR/html4/strict.dtd</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|undeclare-prefixes}}
 
| {{Code|undeclare-prefixes}}
Line 96: Line 91:
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|no}}
 
| {{Code|no}}
| <code>undeclare-prefixes=yes</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|normalization-form}}
 
| {{Code|normalization-form}}
Line 102: Line 96:
 
| {{Code|NFC}}, {{Code|none}}
 
| {{Code|NFC}}, {{Code|none}}
 
| {{Code|NFC}}
 
| {{Code|NFC}}
| <code>normalization-form=none</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|media-type}}
 
| {{Code|media-type}}
 
| Specifies the media type.
 
| Specifies the media type.
 +
| ''string''
 +
| {{Code|application/xml}}
 +
|- valign="top"
 +
| {{Code|parameter-document}}
 +
| Parses the value as XML document with additional serialization parameters (see the [https://www.w3.org/TR/xslt-xquery-serialization-31/#serparams-in-xdm-instance Specification] for more details and examples).
 +
| ''string''
 
|  
 
|  
| {{Code|application/xml}}
 
| <code>media-type=text/plain</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|use-character-maps}}
 
| {{Code|use-character-maps}}
| Defines character mappings (not supported).
+
| Defines character mappings. If mappings are supplied as single string, keys and values are separated by the equal sign, and multiple pairs are separated by commas. Separators that are to be defined as keys or values can be encoded as entities.<br />Example: <code>A=alpha,B=beta</code>
 +
| ''string''
 
|  
 
|  
|
 
|
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|byte-order-mark}}
 
| {{Code|byte-order-mark}}
Line 120: Line 116:
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|no}}
 
| {{Code|no}}
| <code>byte-order-mark=yes</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|escape-uri-attributes}}
 
| {{Code|escape-uri-attributes}}
Line 126: Line 121:
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|no}}
 
| {{Code|no}}
| <code>escape-uri-attributes=yes, method=html</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|include-content-type}}
 
| {{Code|include-content-type}}
| Includes a {{Code|meta}} content-type element if the result is output as HTML<br />Example: <code>&lt;head&gt;&lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;&lt;/head&gt;</code>
+
| Inserts a {{Code|meta}} content-type element into the head element if the result is output as HTML<br />Example: <code>&lt;head&gt;&lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;&lt;/head&gt;</code>. The head element must already exist or nothing will be added. Any existing {{Code|meta}} content-type elements will be removed.
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
| {{Code|no}}
+
| {{Code|yes}}
| <code>include-content-type=yes, method=html</code>
 
 
|}
 
|}
  
BaseX provides some additional, implementation-specific serialization parameters:
+
BaseX provides some additional serialization parameters:
  
 
{| class="wikitable sortable" width="100%"
 
{| class="wikitable sortable" width="100%"
 
|- valign="top"
 
|- valign="top"
! Parameter
+
! width="140" | Parameter
 
! Description
 
! Description
 
! Allowed
 
! Allowed
 
! Default
 
! Default
! Examples
 
 
|- valign="top"
 
|- valign="top"
| {{Code|format}}
+
| {{Code|csv}}
| Turns output formatting on/off, including the conversion of special characters to entities and insertion of item separators.
+
| Defines the way how data is serialized as CSV.
| {{Code|yes}}, {{Code|no}}
+
| see [[CSV Module]]
| {{Code|yes}}
+
|
| <code>format=no</code>
+
|- valign="top"
 +
| {{Code|json}}
 +
| Defines the way how data is serialized as JSON.
 +
| see [[JSON Module]]
 +
|  
 
|- valign="top"
 
|- valign="top"
 
| {{Code|tabulator}}
 
| {{Code|tabulator}}
| Uses tab characters ({{Code|\t}}) for indenting elements.
+
| Uses tab characters ({{Code|\t}}) instead of spaces for indenting elements.
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|yes}}, {{Code|no}}
 
| {{Code|no}}
 
| {{Code|no}}
| <code>tabulator=yes</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|indents}}
 
| {{Code|indents}}
Line 161: Line 156:
 
| ''positive number''
 
| ''positive number''
 
| {{Code|2}}
 
| {{Code|2}}
| <code>indents=1, tabulator=yes</code>
 
|- valign="top"
 
| {{Code|wrap-prefix}},<br />{{Code|wrap-uri}}
 
| Specifies a prefix and/or URI for wrapping the query results.
 
|
 
|
 
| <code>wrap-prefix=rest, wrap-uri=http://basex.org/rest</code>
 
 
|- valign="top"
 
|- valign="top"
 
| {{Code|newline}}
 
| {{Code|newline}}
Line 173: Line 161:
 
| {{Code|\n}}, {{Code|\r\n}}, {{Code|\r}}
 
| {{Code|\n}}, {{Code|\r\n}}, {{Code|\r}}
 
| ''system dependent''
 
| ''system dependent''
| <code>newline=\r\n</code>
 
 
|- valign="top"
 
|- valign="top"
| {{Code|separator}}
+
| {{Code|limit}}
| Determines the string to be used as item separator (deprecated, replaced with {{Code|item-separator}}).
+
| Stops serialization after the specified number of bytes has been serialized. If a negative number is specified, everything will be output.
| {{Code|\n}}, {{Code|\r\n}}, {{Code|\r}}, ''arbitrary strings''
+
| ''positive number''
| ''single space''
+
| {{Code|-1}}
| <code>separator=\n</code>
+
|- valign="top"
 +
| {{Code|binary}}
 +
| Indicates if items of binary type are output in their native byte representation. Only applicable to the <code>base</code> serialization method.
 +
| {{Code|yes}}, {{Code|no}}
 +
| {{Code|yes}}
 
|}
 
|}
 +
 +
The {{Code|csv}} and {{Code|json}} parameters are supplied with a list of options. Option names and values are combined with <code>=</code>, several options are separated by <code>,</code>:
 +
 +
<syntaxhighlight lang="xquery">
 +
declare option output:method "csv";
 +
declare option output:csv "header=yes, separator=semicolon";
 +
<csv>
 +
  <record>
 +
    <Name>John</Name>
 +
    <City>Newton</City>
 +
  </record>
 +
  <record>
 +
    <Name>Jack</Name>
 +
    <City>Oldtown</City>
 +
  </record>
 +
</csv>
 +
</syntaxhighlight>
 +
 +
If {{Code|fn:serialize}} is called, output-specific parameters can be supplied via nested options:
 +
 +
<syntaxhighlight lang="xquery">
 +
serialize(
 +
  <csv>
 +
    <record>
 +
      <Name>John</Name>
 +
      <City>Newton</City>
 +
    </record>
 +
    <record>
 +
      <Name>Jack</Name>
 +
      <City>Oldtown</City>
 +
    </record>
 +
  </csv>,
 +
  map {
 +
    'method': 'csv',
 +
    'csv': map { 'header': 'yes', 'separator': ';' }
 +
  }
 +
)
 +
</syntaxhighlight>
 +
 +
'''Result''':
 +
<syntaxhighlight lang="xml">
 +
Name;City
 +
John;Newton
 +
Jack;Oldtown
 +
</syntaxhighlight>
 +
 +
=Character mappings=
 +
 +
Character maps allow a specific character in the instance of the data model to be replaced with a specified string of characters during serialization. The string that is substituted is output "as is," and the serializer performs no checks that the resulting document is well-formed. This may only occur in documents parsed with {{Code|parameter-document}}. If a character is mapped, then it is not subjected to XML or HTML escaping. For details refer to section [https://www.w3.org/TR/2015/CR-xslt-xquery-serialization-31-20151217/#character-maps 11 Character maps] in the [https://www.w3.org/TR/xslt-xquery-serialization-31 W3C XQuery Serialization 3.1] document
 +
 +
This example maps the Unicode U+00A0 NO-BREAK SPACE as &amp;#160; (without the serialization parameter, the Unicode character would be output):
 +
 +
'''Example query''':
 +
<syntaxhighlight lang="xquery">
 +
declare option output:parameter-document "map.xml";
 +
<x>&amp;#xA0;</x>
 +
</syntaxhighlight>
 +
 +
'''Example parameter-document''':
 +
<syntaxhighlight lang="xml">
 +
<serialization-parameters
 +
  xmlns="http://www.w3.org/2010/xslt-xquery-serialization">
 +
  <use-character-maps>
 +
    <character-map character="&amp;#160;" map-string="&amp;amp;#160;"/>
 +
  </use-character-maps>
 +
</serialization-parameters>
 +
</syntaxhighlight>
  
 
=Changelog=
 
=Changelog=
 +
 +
;Version 9.2
 +
 +
* Updated: New default value for {{Code|include-content-type}} is {{Code|yes}}.
 +
 +
;Version 8.4
 +
 +
* Added: Serialization parameter {{Code|binary}}.
 +
* Updated: New serialization method <code>basex</code>. By default, items of binary type are now output in their native byte representation. The method <code>raw</code> was removed.
 +
 +
;Version 8.0
 +
 +
* Added: Support for {{Code|use-character-maps}} and {{Code|parameter-document}}.
 +
* Added: Serialization method {{Code|adaptive}}.
 +
* Updated: {{Code|adaptive}} is new default method (before: {{Code|xml}}).
 +
* Removed: {{Code|format}}, {{Code|wrap-prefix}}, {{Code|wrap-uri}}.
 +
 +
;Version 7.8.2
 +
 +
* Added: {{Code|limit}}: Stops serialization after the specified number of bytes has been serialized.
 +
 +
;Version 7.8
 +
 +
* Added: {{Code|csv}} and {{Code|json}} serialization parameters.
 +
* Removed: {{Code|separator}} option (use {{Code|item-separator}} instead).
 +
 +
;Version 7.7.2
 +
 +
* Added: {{Code|csv}} serialization method.
 +
* Added: temporary serialization methods {{Code|csv-header}}, {{Code|csv-separator}}, {{Code|json-unescape}}, {{Code|json-spec}}, {{Code|json-format}}.
  
 
;Version 7.5
 
;Version 7.5
  
* Added: official {{Code|item-separator}} and {{Code|html-version}} parameter
+
* Added: official {{Code|item-separator}} and {{Code|html-version}} parameter.
* Updated: <code>method=html5</code> removed; serializers updated with the [http://www.w3.org/TR/2013/WD-xslt-xquery-serialization-30-20130108/ latest version of the specification], using <code>method=html</code> and <code>version=5.0</code>.
+
* Updated: <code>method=html5</code> removed; serializers updated with the [https://www.w3.org/TR/2013/WD-xslt-xquery-serialization-30-20130108/ latest version of the specification], using <code>method=html</code> and <code>version=5.0</code>.
  
 
;Version 7.2
 
;Version 7.2
  
* Added: {{Code|separator}} parameter
+
* Added: {{Code|separator}} parameter.
  
 
;Version 7.1
 
;Version 7.1
  
* Added: {{Code|newline}} parameter
+
* Added: {{Code|newline}} parameter.
  
 
;Version 7.0
 
;Version 7.0
  
* Added: Serialization parameters added to [[REST API]]; JSON/JsonML/raw methods
+
* Added: Serialization parameters added to [[REST API]]; JSON/JsonML/raw methods.

Latest revision as of 14:35, 22 June 2022

This page is part of the XQuery Portal.

Serialization parameters define how XQuery items and XML nodes will be serialized (i.e., returned to the client or an API, usually in textual form). The official parameters are defined in the W3C XQuery Serialization 3.1 document. In BaseX, they can be:

The namespace for serialization parameters is statically bound to the output prefix. This means that it need not (but may) be declared in the query prolog:

declare namespace output = 'http://www.w3.org/2010/xslt-xquery-serialization';
declare option output:method 'text';
<xml>Hi there</xml>

Due to the wide range of ways how parameters can be supplied, we deliberately ignored one rule of the specification, which requires non-official features to be defined in a non-null namespace URI. In the following, we will indicate which features are specific to our implementation.

Parameters[edit]

The following serialization parameters are supported by BaseX (further details can be looked up in the official specification):

Parameter Description Allowed Default
method Specifies the serialization method. xml, xhtml, html, text and adaptive are part of the official specification. For more details on basex, csv and json, see XQuery Extensions. xml, xhtml, html, text, json, adaptive, csv, basex basex
version Specifies the version of the serialization method. xml/xhtml: 1.0, 1.1
html: 4.0, 4.01, 5.0
1.0
html-version Specifies the version of the HTML serialization method. 4.0, 4.01, 5.0 4.0
item-separator Determines a string to be used as item separator. If a separator is specified, the default separation of atomic values with single whitespaces will be skipped. string
encoding Encoding to be used for outputting the data. all encodings supported by Java UTF-8
indent Adjusts whitespaces to make the output better readable. yes, no yes
cdata-section-elements List of elements to be output as CDATA, separated by whitespaces.
Example: <text><![CDATA[ <> ]]></text>
string
omit-xml-declaration Omits the XML declaration, which is serialized before the actual query result
Example: <?xml version="1.0" encoding="UTF-8"?>
yes, no yes
standalone Prints or omits the "standalone" attribute in the XML declaration. yes, no, omit omit
doctype-system Introduces the output with a document type declaration and the given system identifier.
Example: <!DOCTYPE x SYSTEM "entities.dtd">
string
doctype-public If doctype-system is specified, adds a public identifier.
Example: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
string
undeclare-prefixes Undeclares prefixes in XML 1.1. yes, no no
normalization-form Specifies a normalization form. BaseX supports Form C (NFC). NFC, none NFC
media-type Specifies the media type. string application/xml
parameter-document Parses the value as XML document with additional serialization parameters (see the Specification for more details and examples). string
use-character-maps Defines character mappings. If mappings are supplied as single string, keys and values are separated by the equal sign, and multiple pairs are separated by commas. Separators that are to be defined as keys or values can be encoded as entities.
Example: A=alpha,B=beta
string
byte-order-mark Prints a byte-order-mark before starting serialization. yes, no no
escape-uri-attributes Escapes URI information in certain HTML attributes
Example: <a href="%C3%A4%C3%B6%C3%BC">äöü<a>
yes, no no
include-content-type Inserts a meta content-type element into the head element if the result is output as HTML
Example: <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head>. The head element must already exist or nothing will be added. Any existing meta content-type elements will be removed.
yes, no yes

BaseX provides some additional serialization parameters:

Parameter Description Allowed Default
csv Defines the way how data is serialized as CSV. see CSV Module
json Defines the way how data is serialized as JSON. see JSON Module
tabulator Uses tab characters (\t) instead of spaces for indenting elements. yes, no no
indents Specifies the number of characters to be indented. positive number 2
newline Specifies the type of newline to be used as end-of-line marker. \n, \r\n, \r system dependent
limit Stops serialization after the specified number of bytes has been serialized. If a negative number is specified, everything will be output. positive number -1
binary Indicates if items of binary type are output in their native byte representation. Only applicable to the base serialization method. yes, no yes

The csv and json parameters are supplied with a list of options. Option names and values are combined with =, several options are separated by ,:

declare option output:method "csv";
declare option output:csv "header=yes, separator=semicolon";
<csv>
  <record>
    <Name>John</Name>
    <City>Newton</City>
  </record>
  <record>
    <Name>Jack</Name>
    <City>Oldtown</City>
  </record>
</csv>

If fn:serialize is called, output-specific parameters can be supplied via nested options:

serialize(
  <csv>
    <record>
      <Name>John</Name>
      <City>Newton</City>
    </record>
    <record>
      <Name>Jack</Name>
      <City>Oldtown</City>
    </record>
  </csv>,
  map {
    'method': 'csv',
    'csv': map { 'header': 'yes', 'separator': ';' }
  }
)

Result:

Name;City
John;Newton
Jack;Oldtown

Character mappings[edit]

Character maps allow a specific character in the instance of the data model to be replaced with a specified string of characters during serialization. The string that is substituted is output "as is," and the serializer performs no checks that the resulting document is well-formed. This may only occur in documents parsed with parameter-document. If a character is mapped, then it is not subjected to XML or HTML escaping. For details refer to section 11 Character maps in the W3C XQuery Serialization 3.1 document

This example maps the Unicode U+00A0 NO-BREAK SPACE as &#160; (without the serialization parameter, the Unicode character would be output):

Example query:

declare option output:parameter-document "map.xml";
<x>&amp;#xA0;</x>

Example parameter-document:

<serialization-parameters
   xmlns="http://www.w3.org/2010/xslt-xquery-serialization">
   <use-character-maps>
     <character-map character="&amp;#160;" map-string="&amp;amp;#160;"/>
   </use-character-maps>
</serialization-parameters>

Changelog[edit]

Version 9.2
  • Updated: New default value for include-content-type is yes.
Version 8.4
  • Added: Serialization parameter binary.
  • Updated: New serialization method basex. By default, items of binary type are now output in their native byte representation. The method raw was removed.
Version 8.0
  • Added: Support for use-character-maps and parameter-document.
  • Added: Serialization method adaptive.
  • Updated: adaptive is new default method (before: xml).
  • Removed: format, wrap-prefix, wrap-uri.
Version 7.8.2
  • Added: limit: Stops serialization after the specified number of bytes has been serialized.
Version 7.8
  • Added: csv and json serialization parameters.
  • Removed: separator option (use item-separator instead).
Version 7.7.2
  • Added: csv serialization method.
  • Added: temporary serialization methods csv-header, csv-separator, json-unescape, json-spec, json-format.
Version 7.5
  • Added: official item-separator and html-version parameter.
  • Updated: method=html5 removed; serializers updated with the latest version of the specification, using method=html and version=5.0.
Version 7.2
  • Added: separator parameter.
Version 7.1
  • Added: newline parameter.
Version 7.0
  • Added: Serialization parameters added to REST API; JSON/JsonML/raw methods.