Difference between revisions of "JSON Module"
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− | This [[Module Library|XQuery Module]] contains functions to parse and serialize JSON | + | This [[Module Library|XQuery Module]] contains functions to parse and serialize JSON data [https://www.json.org/ JSON (JavaScript Object Notation)] is a popular data exchange format for applications written in JavaScript. As there are notable differences between JSON and XML, or XQuery data types, no mapping exists that guarantees a lossless, bidirectional conversion between JSON and XML. For this reason, we offer various mappings, all of which are suited to different use cases. |
=Conventions= | =Conventions= | ||
− | All functions in this module are assigned to the <code><nowiki>http://basex.org/modules/json</nowiki></code> namespace, which is statically bound to the {{Code|json}} prefix.<br/> | + | All functions and errors in this module are assigned to the <code><nowiki>http://basex.org/modules/json</nowiki></code> namespace, which is statically bound to the {{Code|json}} prefix.<br/> |
− | |||
==Conversion Formats== | ==Conversion Formats== | ||
+ | |||
+ | '''A little advice''': in the Database Creation dialog of the GUI, if you select JSON Parsing and switch to the ''Parsing'' tab, you can see the effects of some of the conversion options. | ||
===Direct=== | ===Direct=== | ||
Line 12: | Line 13: | ||
The {{Code|direct}} conversion format allows a lossless conversion from JSON to XML and back. The transformation is based on the following rules: | The {{Code|direct}} conversion format allows a lossless conversion from JSON to XML and back. The transformation is based on the following rules: | ||
− | * The resulting document has a {{Code| | + | * The resulting document has a {{Code|json}} root node. |
− | * Object pairs are represented via elements. The name of a pair is | + | * Object pairs are represented via elements. The name of a pair is encoded, as described in the [[Conversion Module#Keys|Conversion Module]], and used as element name. |
− | + | * Array entries are also represented via elements, with {{Code|_}} as element name. | |
− | |||
− | * Array entries are also represented via elements | ||
* Object and array values are stored in text nodes. | * Object and array values are stored in text nodes. | ||
* The types of values are represented via {{Code|type}} attributes: | * The types of values are represented via {{Code|type}} attributes: | ||
Line 26: | Line 25: | ||
The {{Code|attributes}} format is lossless, too. The transformation based on the following rules: | The {{Code|attributes}} format is lossless, too. The transformation based on the following rules: | ||
− | * The resulting document has a {{Code| | + | * The resulting document has a {{Code|json}} root node. |
− | * Object pairs are represented via {{Code| | + | * Object pairs are represented via {{Code|pair}} elements. The name of a pair is stored in a {{Code|name}} attribute. |
− | * Array entries are represented via {{Code| | + | * Array entries are represented via {{Code|item}} elements. |
* Object and array values are stored in text nodes. | * Object and array values are stored in text nodes. | ||
* The types of values are represented via {{Code|type}} attributes: | * The types of values are represented via {{Code|type}} attributes: | ||
** The existing types are ''string'', ''number'', ''boolean'', ''null'', ''object'', and ''array''. | ** The existing types are ''string'', ''number'', ''boolean'', ''null'', ''object'', and ''array''. | ||
** As most values are strings, the ''string'' type is by default omitted. | ** As most values are strings, the ''string'' type is by default omitted. | ||
− | |||
− | |||
− | |||
− | |||
===Basic=== | ===Basic=== | ||
Line 46: | Line 41: | ||
The {{Code|jsonml}} format is designed to convert XML to JSON and back, using the JsonML dialect. JsonML allows the transformation of arbitrary XML documents, but namespaces, comments and processing instructions will be discarded in the transformation process. More details are found in the official [http://jsonml.org/XML JsonML documentation]. | The {{Code|jsonml}} format is designed to convert XML to JSON and back, using the JsonML dialect. JsonML allows the transformation of arbitrary XML documents, but namespaces, comments and processing instructions will be discarded in the transformation process. More details are found in the official [http://jsonml.org/XML JsonML documentation]. | ||
− | + | ===XQuery=== | |
+ | |||
+ | The {{Code|xquery}} format is lossless, too. It converts JSON data to an XQuery value (a map, array, string, number, boolean, or empty sequence) and vice versa. The conversion rules are the same as for [[XQuery 3.1#fn:parse-json|fn:parse-json]]. | ||
+ | |||
+ | The resulting representation consumes less memory than XML-based formats, and values can be directly accessed without conversion. Thus, it is recommendable for very large inputs and for efficient ad-hoc processing. | ||
==Options== | ==Options== | ||
Line 61: | Line 60: | ||
|- valign="top" | |- valign="top" | ||
| {{Code|format}} | | {{Code|format}} | ||
− | | Specifies the format for converting JSON data. | + | | Specifies the format for converting JSON data ([[#Conversion Formats|see above]]). |
− | | {{Code|direct}}, {{Code|attributes}}, {{Code|jsonml}}, {{Code| | + | | {{Code|direct}}, {{Code|attributes}}, {{Code|basic}}, {{Code|jsonml}}, {{Code|xquery}} |
| {{Code|direct}} | | {{Code|direct}} | ||
| ''parse'', ''serialize'' | | ''parse'', ''serialize'' | ||
|- valign="top" | |- valign="top" | ||
| {{Code|liberal}} | | {{Code|liberal}} | ||
− | | Determines if minor deviations from [ | + | | Determines if minor deviations from [https://www.rfc-editor.org/rfc/rfc7159.txt RFC 7159] will be ignored. |
| {{Code|yes}}, {{Code|no}} | | {{Code|yes}}, {{Code|no}} | ||
| {{Code|no}} | | {{Code|no}} | ||
Line 74: | Line 73: | ||
| {{Code|merge}} | | {{Code|merge}} | ||
| This option is considered when {{Code|direct}} or {{Code|attributes}} conversion is used:<br/> | | This option is considered when {{Code|direct}} or {{Code|attributes}} conversion is used:<br/> | ||
− | * If a name has the same type throughout the | + | * If a name has the same type throughout the data, the {{Code|type}} attribute will be omitted. Instead, the name will be listed in additional, type-specific attributes in the root node. |
* The attributes are named by their type in plural (''numbers'', ''booleans'', ''nulls'', ''objects'' and ''arrays''), and the attribute value contains all names with that type, separated by whitespaces. | * The attributes are named by their type in plural (''numbers'', ''booleans'', ''nulls'', ''objects'' and ''arrays''), and the attribute value contains all names with that type, separated by whitespaces. | ||
| {{Code|yes}}, {{Code|no}} | | {{Code|yes}}, {{Code|no}} | ||
Line 87: | Line 86: | ||
|- valign="top" | |- valign="top" | ||
| {{Code|lax}} | | {{Code|lax}} | ||
− | | Specifies if | + | | Specifies if [[Conversion Module#Keys|lax conversion rules]] are used to convert QNames to JSON names. |
| {{Code|yes}}, {{Code|no}} | | {{Code|yes}}, {{Code|no}} | ||
| {{Code|no}} | | {{Code|no}} | ||
Line 107: | Line 106: | ||
| Indicates if whitespace should be added to the output with the aim of improving human legibility. If the parameter is set as in the query prolog, it overrides the {{Code|indent}} [[Serialization|serialization parameter]]. | | Indicates if whitespace should be added to the output with the aim of improving human legibility. If the parameter is set as in the query prolog, it overrides the {{Code|indent}} [[Serialization|serialization parameter]]. | ||
| {{Code|yes}}, {{Code|no}} | | {{Code|yes}}, {{Code|no}} | ||
− | | {{Code| | + | | {{Code|no}} |
| ''serialize'' | | ''serialize'' | ||
|} | |} | ||
=Functions= | =Functions= | ||
+ | |||
+ | ==json:doc== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- valign="top" | ||
+ | | width='120' | '''Signature''' | ||
+ | |<pre>json:doc( | ||
+ | $href as xs:string, | ||
+ | $options as map(*)? := map { } | ||
+ | ) as item()?</pre> | ||
+ | |- valign="top" | ||
+ | | '''Summary''' | ||
+ | |Fetches the JSON document referred to by the given {{Code|$href}} and converts it to an XQuery value. The {{Code|$options}} argument can be used to control the way the input is converted. | ||
+ | |- valign="top" | ||
+ | | '''Errors''' | ||
+ | |{{Error|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting. | ||
+ | |} | ||
==json:parse== | ==json:parse== | ||
{| width='100%' | {| width='100%' | ||
− | |- | + | |- valign="top" |
− | | width='120' | ''' | + | | width='120' | '''Signature''' |
− | | | + | |<pre>json:parse( |
− | |- | + | $value as xs:string?, |
+ | $options as map(*)? := map { } | ||
+ | ) as item()?</pre> | ||
+ | |- valign="top" | ||
| '''Summary''' | | '''Summary''' | ||
− | |Converts the JSON | + | |Converts the JSON {{Code|$value}} to an XQuery value. If the input can be successfully parsed, it can be serialized back to the original JSON representation. The {{Code|$options}} argument can be used to control the way the input is converted. |
− | |- | + | |- valign="top" |
| '''Errors''' | | '''Errors''' | ||
− | |{{Error| | + | |{{Error|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting. |
|} | |} | ||
Line 130: | Line 149: | ||
{| width='100%' | {| width='100%' | ||
− | |- | + | |- valign="top" |
− | | width='120' | ''' | + | | width='120' | '''Signature''' |
− | | | + | |<pre>json:serialize( |
− | |- | + | $input as item()?, |
+ | $options as map(*)? := map { } | ||
+ | ) as xs:string</pre> | ||
+ | |- valign="top" | ||
| '''Summary''' | | '''Summary''' | ||
− | |Serializes the | + | |Serializes the specified {{Code|$input}} as JSON, using the specified {{Code|$options}}, and returns the result as string: |
− | |- | + | * The input is expected to conform to the results that are created by {{Function||json:parse}}. |
+ | * Non-conforming items will be serialized as specified in the [[XQuery 3.1#JSON Serialization|json output method]] of the official recommendation. | ||
+ | Values can also be serialized as JSON with the standard [[Serialization]] feature of XQuery: | ||
+ | * The parameter {{Code|method}} needs to be set to {{Code|json}}, and | ||
+ | * the options presented in this article need to be assigned to the {{Code|json}} parameter. | ||
+ | |- valign="top" | ||
| '''Errors''' | | '''Errors''' | ||
− | |{{Error| | + | |{{Error|serialize|#Errors}} the specified node cannot be serialized as JSON document. |
|} | |} | ||
Line 148: | Line 175: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
let $database := "database" | let $database := "database" | ||
for $name in file:list('.', false(), '*.json') | for $name in file:list('.', false(), '*.json') | ||
Line 159: | Line 186: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
json:parse('{}') | json:parse('{}') | ||
</pre> | </pre> | ||
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"> |
<json type="object"/> | <json type="object"/> | ||
</pre> | </pre> | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
(: serialize result as plain text :) | (: serialize result as plain text :) | ||
declare option output:method 'text'; | declare option output:method 'text'; | ||
Line 176: | Line 203: | ||
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang='xquery'> |
{ } | { } | ||
</pre> | </pre> | ||
Line 183: | Line 210: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
json:parse('{ | json:parse('{ | ||
"title": "Talk On Travel Pool", | "title": "Talk On Travel Pool", | ||
Line 194: | Line 221: | ||
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"> |
<json type="object"> | <json type="object"> | ||
<title>Talk On Travel Pool</title> | <title>Talk On Travel Pool</title> | ||
Line 207: | Line 234: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
let $options := map { 'merge': true() } | let $options := map { 'merge': true() } | ||
return json:parse('{ | return json:parse('{ | ||
Line 232: | Line 259: | ||
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"> |
<json numbers="age code" arrays="phone" objects="json address value"> | <json numbers="age code" arrays="phone" objects="json address value"> | ||
<first__name>John</first__name> | <first__name>John</first__name> | ||
Line 257: | Line 284: | ||
==JsonML Format== | ==JsonML Format== | ||
− | '''Example 1: Converts all XML documents in a database to JsonML and writes them to disk''' | + | '''Example 1: Converts all XML documents in a database to the JsonML format and writes them to disk''' |
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
for $doc in collection('json') | for $doc in collection('json') | ||
let $name := document-uri($doc) | let $name := document-uri($doc) | ||
− | let $json := json:serialize($doc) | + | let $json := json:serialize($doc, map { 'format': 'jsonml' }) |
return file:write($name, $json) | return file:write($name, $json) | ||
</pre> | </pre> | ||
− | '''Example 2: Converts | + | '''Example 2: Converts an XML document with elements and text''' |
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
json:serialize(doc('flickr.xml'), map { 'format': 'jsonml' }) | json:serialize(doc('flickr.xml'), map { 'format': 'jsonml' }) | ||
</pre> | </pre> | ||
'''flickr.xml:''' | '''flickr.xml:''' | ||
− | <pre | + | <pre lang="xml"> |
<flickr> | <flickr> | ||
<title>Talk On Travel Pool</title> | <title>Talk On Travel Pool</title> | ||
Line 298: | Line 313: | ||
'''Result:''' | '''Result:''' | ||
− | <pre> | + | <pre lang="json"> |
["flickr", | ["flickr", | ||
["title", | ["title", | ||
Line 312: | Line 327: | ||
</pre> | </pre> | ||
− | '''Example | + | '''Example 3: Converts a document with nested elements and attributes to JsonML''' |
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
json:serialize(doc('input.xml'), map { 'format': 'jsonml' }) | json:serialize(doc('input.xml'), map { 'format': 'jsonml' }) | ||
</pre> | </pre> | ||
'''input.xml:''' | '''input.xml:''' | ||
− | <pre | + | <pre lang="xml"> |
<address id='1'> | <address id='1'> | ||
<!-- comments will be discarded --> | <!-- comments will be discarded --> | ||
Line 335: | Line 350: | ||
'''Result:''' | '''Result:''' | ||
− | <pre> | + | <pre lang="json"> |
["address", {"id":"1"}, | ["address", {"id":"1"}, | ||
["last_name", | ["last_name", | ||
Line 350: | Line 365: | ||
["phone", {"type":"home"}, | ["phone", {"type":"home"}, | ||
"212 555-1234"]] | "212 555-1234"]] | ||
+ | </pre> | ||
+ | |||
+ | ==XQuery Format== | ||
+ | |||
+ | '''Example 1: Converts a JSON string to XQuery''' | ||
+ | |||
+ | '''Query:''' | ||
+ | <pre lang='xquery'> | ||
+ | let $input := '{ | ||
+ | "Title": "Drinks", | ||
+ | "Author": [ "Jim Daniels", "Jack Beam" ] | ||
+ | }' | ||
+ | let $data := json:parse($input, map { 'format': 'xquery' }) | ||
+ | return map:for-each($data, function($k, $v) { | ||
+ | $k || ': ' || string-join($v, ', ') | ||
+ | }) | ||
+ | </pre> | ||
+ | |||
+ | '''Result:''' | ||
+ | <pre lang="json"> | ||
+ | Author: Jim Daniels, Jack Beam | ||
+ | Title: Drinks | ||
+ | </pre> | ||
+ | |||
+ | '''Example 2: Converts XQuery data to JSON''' | ||
+ | |||
+ | '''Query:''' | ||
+ | <pre lang='xquery'> | ||
+ | for $item in ( | ||
+ | true(), | ||
+ | 'ABC', | ||
+ | array { 1 to 5 }, | ||
+ | map { "Key": "Value" } | ||
+ | ) | ||
+ | return json:serialize( | ||
+ | $item, | ||
+ | map { 'format': 'xquery', 'indent': 'no' } | ||
+ | ) | ||
+ | </pre> | ||
+ | |||
+ | '''Result:''' | ||
+ | <pre lang="json"> | ||
+ | true | ||
+ | "ABC" | ||
+ | [1,2,3,4,5] | ||
+ | {"Key":"Value"} | ||
</pre> | </pre> | ||
Line 357: | Line 418: | ||
! width="110"|Code | ! width="110"|Code | ||
|Description | |Description | ||
− | |- | + | |- valign="top" |
− | |{{Code| | + | |{{Code|options}} |
+ | |The specified options are conflicting. | ||
+ | |- valign="top" | ||
+ | |{{Code|parse}} | ||
|The specified input cannot be parsed as JSON document. | |The specified input cannot be parsed as JSON document. | ||
− | |- | + | |- valign="top" |
− | |{{Code| | + | |{{Code|serialize}} |
|The specified node cannot be serialized as JSON document. | |The specified node cannot be serialized as JSON document. | ||
|} | |} | ||
=Changelog= | =Changelog= | ||
+ | |||
+ | ;Version 10.0 | ||
+ | * Updated: {{Code|indent}}: Default changed from {{Code|yes}} to {{Code|no}}. | ||
+ | |||
+ | ;Version 9.4 | ||
+ | * Added: {{Function||json:doc}} | ||
+ | |||
+ | ; Version 9.1 | ||
+ | * Updated: {{Function||json:parse}} can be called with empty sequence. | ||
+ | |||
+ | ;Version 9.0 | ||
+ | * Updated: <code>map</code> format renamed to <code>xquery</code>. | ||
+ | * Updated: error codes updated; errors now use the module namespace | ||
;Version 8.4 | ;Version 8.4 | ||
Line 383: | Line 460: | ||
;Version 7.7.2 | ;Version 7.7.2 | ||
− | * Updated: {{Code|$options}} argument added to | + | * Updated: {{Code|$options}} argument added to {{Function||json:parse}} and {{Function||json:serialize}}. |
− | * Updated: | + | * Updated: {{Function||json:parse-ml}} and {{Function||json:serialize-ml}} are now ''deprecated''. |
The module was introduced with Version 7.0. | The module was introduced with Version 7.0. |
Latest revision as of 18:38, 1 December 2023
This XQuery Module contains functions to parse and serialize JSON data JSON (JavaScript Object Notation) is a popular data exchange format for applications written in JavaScript. As there are notable differences between JSON and XML, or XQuery data types, no mapping exists that guarantees a lossless, bidirectional conversion between JSON and XML. For this reason, we offer various mappings, all of which are suited to different use cases.
Contents
Conventions[edit]
All functions and errors in this module are assigned to the http://basex.org/modules/json
namespace, which is statically bound to the json
prefix.
Conversion Formats[edit]
A little advice: in the Database Creation dialog of the GUI, if you select JSON Parsing and switch to the Parsing tab, you can see the effects of some of the conversion options.
Direct[edit]
The direct
conversion format allows a lossless conversion from JSON to XML and back. The transformation is based on the following rules:
- The resulting document has a
json
root node. - Object pairs are represented via elements. The name of a pair is encoded, as described in the Conversion Module, and used as element name.
- Array entries are also represented via elements, with
_
as element name. - Object and array values are stored in text nodes.
- The types of values are represented via
type
attributes:- The existing types are string, number, boolean, null, object, and array.
- As most values are strings, the string type is by default omitted.
Attributes[edit]
The attributes
format is lossless, too. The transformation based on the following rules:
- The resulting document has a
json
root node. - Object pairs are represented via
pair
elements. The name of a pair is stored in aname
attribute. - Array entries are represented via
item
elements. - Object and array values are stored in text nodes.
- The types of values are represented via
type
attributes:- The existing types are string, number, boolean, null, object, and array.
- As most values are strings, the string type is by default omitted.
Basic[edit]
The basic
format is another lossless format. It converts a JSON document to an XML node and vice versa. The conversion rules are the same as for fn:json-to-xml.
JsonML[edit]
The jsonml
format is designed to convert XML to JSON and back, using the JsonML dialect. JsonML allows the transformation of arbitrary XML documents, but namespaces, comments and processing instructions will be discarded in the transformation process. More details are found in the official JsonML documentation.
XQuery[edit]
The xquery
format is lossless, too. It converts JSON data to an XQuery value (a map, array, string, number, boolean, or empty sequence) and vice versa. The conversion rules are the same as for fn:parse-json.
The resulting representation consumes less memory than XML-based formats, and values can be directly accessed without conversion. Thus, it is recommendable for very large inputs and for efficient ad-hoc processing.
Options[edit]
The following options are available (the Direction column indicates if an option applies to parsing, serialization, or both operations):
Option | Description | Allowed | Default | Direction |
---|---|---|---|---|
format
|
Specifies the format for converting JSON data (see above). | direct , attributes , basic , jsonml , xquery
|
direct
|
parse, serialize |
liberal
|
Determines if minor deviations from RFC 7159 will be ignored. | yes , no
|
no
|
parse |
merge
|
This option is considered when direct or attributes conversion is used:
|
yes , no
|
no
|
parse, serialize |
strings
|
Indicates if type attributes will be added for strings.
|
yes , no
|
yes
|
parse, serialize |
lax
|
Specifies if lax conversion rules are used to convert QNames to JSON names. | yes , no
|
no
|
parse, serialize |
escape
|
Indicates if escaped characters are expanded (for example, \n becomes a single x0A character, while \u20AC becomes the character € ).
|
yes , no
|
yes
|
parse |
escape
|
Indicates if characters are escaped whenever the JSON syntax requires it. This option can be set to no if strings are already in escaped form and no further escaping is permitted.
|
yes , no
|
yes
|
serialize |
indent
|
Indicates if whitespace should be added to the output with the aim of improving human legibility. If the parameter is set as in the query prolog, it overrides the indent serialization parameter.
|
yes , no
|
no
|
serialize |
Functions[edit]
json:doc[edit]
Signature | json:doc( $href as xs:string, $options as map(*)? := map { } ) as item()? |
Summary | Fetches the JSON document referred to by the given $href and converts it to an XQuery value. The $options argument can be used to control the way the input is converted.
|
Errors | parse : the specified input cannot be parsed as JSON document.options : the specified options are conflicting.
|
json:parse[edit]
Signature | json:parse( $value as xs:string?, $options as map(*)? := map { } ) as item()? |
Summary | Converts the JSON $value to an XQuery value. If the input can be successfully parsed, it can be serialized back to the original JSON representation. The $options argument can be used to control the way the input is converted.
|
Errors | parse : the specified input cannot be parsed as JSON document.options : the specified options are conflicting.
|
json:serialize[edit]
Signature | json:serialize( $input as item()?, $options as map(*)? := map { } ) as xs:string |
Summary | Serializes the specified $input as JSON, using the specified $options , and returns the result as string:
Values can also be serialized as JSON with the standard Serialization feature of XQuery:
|
Errors | serialize : the specified node cannot be serialized as JSON document.
|
Examples[edit]
BaseX Format[edit]
Example 1: Adds all JSON documents in a directory to a database
Query:
let $database := "database"
for $name in file:list('.', false(), '*.json')
let $file := file:read-text($name)
let $json := json:parse($file)
return db:add($database, $json, $name)
Example 2: Converts a simple JSON string to XML and back
Query:
json:parse('{}')
Result:
<json type="object"/>
Query:
(: serialize result as plain text :)
declare option output:method 'text';
json:serialize(<json type="object"/>)
Result:
{ }
Example 3: Converts a JSON string with simple objects and arrays
Query:
json:parse('{
"title": "Talk On Travel Pool",
"link": "http://www.flickr.com/groups/talkontravel/pool/",
"description": "Travel and vacation photos from around the world.",
"modified": "2014-02-02T11:10:27Z",
"generator": "http://www.flickr.com/"
}')
Result:
<json type="object">
<title>Talk On Travel Pool</title>
<link>http://www.flickr.com/groups/talkontravel/pool/</link>
<description>Travel and vacation photos from around the world.</description>
<modified>2014-02-02T11:10:27Z</modified>
<generator>http://www.flickr.com/</generator>
</json>
Example 4: Converts a JSON string with different data types
Query:
let $options := map { 'merge': true() }
return json:parse('{
"first_name": "John",
"last_name": "Smith",
"age": 25,
"address": {
"street": "21 2nd Street",
"city": "New York",
"code": 10021
},
"phone": [
{
"type": "home",
"number": "212 555-1234"
},
{
"type": "mobile",
"number": 1327724623
}
]
}', $options)
Result:
<json numbers="age code" arrays="phone" objects="json address value">
<first__name>John</first__name>
<last__name>Smith</last__name>
<age>25</age>
<address>
<street>21 2nd Street</street>
<city>New York</city>
<code>10021</code>
</address>
<phone>
<_>
<type>home</type>
<number>212 555-1234</number>
</_>
<_>
<type>mobile</type>
<number type="number">1327724623</number>
</_>
</phone>
</json>
JsonML Format[edit]
Example 1: Converts all XML documents in a database to the JsonML format and writes them to disk
Query:
for $doc in collection('json')
let $name := document-uri($doc)
let $json := json:serialize($doc, map { 'format': 'jsonml' })
return file:write($name, $json)
Example 2: Converts an XML document with elements and text
Query:
json:serialize(doc('flickr.xml'), map { 'format': 'jsonml' })
flickr.xml:
<flickr>
<title>Talk On Travel Pool</title>
<link>http://www.flickr.com/groups/talkontravel/pool/</link>
<description>Travel and vacation photos from around the world.</description>
<modified>2014-02-02T11:10:27Z</modified>
<generator>http://www.flickr.com/</generator>
</flickr>
Result:
["flickr",
["title",
"Talk On Travel Pool"],
["link",
"http://www.flickr.com/groups/talkontravel/pool/"],
["description",
"Travel and vacation photos from around the world."],
["modified",
"2014-02-02T11:10:27Z"],
["generator",
"http://www.flickr.com/"]]
Example 3: Converts a document with nested elements and attributes to JsonML
Query:
json:serialize(doc('input.xml'), map { 'format': 'jsonml' })
input.xml:
<address id='1'>
<!-- comments will be discarded -->
<last_name>Smith</last_name>
<age>25</age>
<address xmlns='will be dropped as well'>
<street>21 2nd Street</street>
<city>New York</city>
<code>10021</code>
</address>
<phone type='home'>212 555-1234</phone>
</address>
Result:
["address", {"id":"1"},
["last_name",
"Smith"],
["age",
"25"],
["address",
["street",
"21 2nd Street"],
["city",
"New York"],
["code",
"10021"]],
["phone", {"type":"home"},
"212 555-1234"]]
XQuery Format[edit]
Example 1: Converts a JSON string to XQuery
Query:
let $input := '{
"Title": "Drinks",
"Author": [ "Jim Daniels", "Jack Beam" ]
}'
let $data := json:parse($input, map { 'format': 'xquery' })
return map:for-each($data, function($k, $v) {
$k || ': ' || string-join($v, ', ')
})
Result:
Author: Jim Daniels, Jack Beam
Title: Drinks
Example 2: Converts XQuery data to JSON
Query:
for $item in (
true(),
'ABC',
array { 1 to 5 },
map { "Key": "Value" }
)
return json:serialize(
$item,
map { 'format': 'xquery', 'indent': 'no' }
)
Result:
true
"ABC"
[1,2,3,4,5]
{"Key":"Value"}
Errors[edit]
Code | Description |
---|---|
options
|
The specified options are conflicting. |
parse
|
The specified input cannot be parsed as JSON document. |
serialize
|
The specified node cannot be serialized as JSON document. |
Changelog[edit]
- Version 10.0
- Updated:
indent
: Default changed fromyes
tono
.
- Version 9.4
- Added:
json:doc
- Version 9.1
- Updated:
json:parse
can be called with empty sequence.
- Version 9.0
- Updated:
map
format renamed toxquery
. - Updated: error codes updated; errors now use the module namespace
- Version 8.4
- Updated:
unescape
changed toescape
.
- Version 8.2
- Added: Conversion format
basic
.
- Version 8.0
- Updated: Serialization aligned with the
json
output method of the official specification. - Added:
liberal
option. - Removed:
spec
option.
- Version 7.8
- Removed:
json:parse-ml
,json:serialize-ml
. - Updated:
json:parse
now returns a document node instead of an element, or an XQuery map ifformat
is set to.map
.
- Version 7.7.2
- Updated:
$options
argument added tojson:parse
andjson:serialize
. - Updated:
json:parse-ml
andjson:serialize-ml
are now deprecated.
The module was introduced with Version 7.0.