Difference between revisions of "JSON Module"

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m (Text replacement - "[http://www.json.org" to "[https://www.json.org")
m (Text replacement - "syntaxhighlight" to "pre")
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|- 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|xquery}}
+
| {{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 [http://www.rfc-editor.org/rfc/rfc7159.txt RFC 7159] will be ignored.
+
| 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 86: Line 86:
 
|- valign="top"
 
|- valign="top"
 
| {{Code|lax}}
 
| {{Code|lax}}
| Specifies if a lax approach is used to convert QNames to JSON names.
+
| 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 106: 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|yes}}
+
| {{Code|no}}
 
| ''serialize''
 
| ''serialize''
 
|}
 
|}
Line 112: Line 112:
 
=Functions=
 
=Functions=
  
==json:parse==
+
==json:doc==
  
 
{| width='100%'
 
{| width='100%'
|-
+
|- valign="top"
| width='120' | '''Signatures'''
+
| width='120' | '''Signature'''
|{{Func|json:parse|$string as xs:string?|item()?}}<br/>{{Func|json:parse|$string as xs:string?, $options as map(*)?|item()?}}
+
|<pre>json:doc(
|-
+
  $href    as xs:string,
 +
  $options as map(*)?   := map { }
 +
) as item()?</pre>
 +
|- valign="top"
 
| '''Summary'''
 
| '''Summary'''
|Converts the JSON {{Code|$string}} to an XQuery value. If the input can be successfully parsed, it can be serialized back to the original JSON representation. The {{Code|$options}} argument can be used to control the way the input is converted.
+
|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'''
 
| '''Errors'''
 
|{{Error|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting.
 
|{{Error|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting.
 
|}
 
|}
  
==json:doc==
+
==json:parse==
 
 
{{Mark|Introduced with BaseX 9.4:}}
 
  
 
{| width='100%'
 
{| width='100%'
|-
+
|- valign="top"
| width='120' | '''Signatures'''
+
| width='120' | '''Signature'''
|{{Func|json:doc|$uri as xs:string|item()?}}<br />{{Func|json:doc|$uri as xs:string, $options as map(*)?|item()?}}<br />
+
|<pre>json:parse(
|-
+
  $value  as xs:string?,
 +
  $options as map(*)?     := map { }
 +
) as item()?</pre>
 +
|- valign="top"
 
| '''Summary'''
 
| '''Summary'''
|Fetches the JSON document referred to by the given {{Code|$uri}} and converts it to an XQuery value. The {{Code|$options}} argument can be used to control the way the input is converted.
+
|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|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting.
 
|{{Error|parse|#Errors}} the specified input cannot be parsed as JSON document.<br/>{{Error|options|#Errors}} the specified options are conflicting.
Line 145: Line 149:
  
 
{| width='100%'
 
{| width='100%'
|-
+
|- valign="top"
| width='120' | '''Signatures'''
+
| width='120' | '''Signature'''
|{{Func|json:serialize|$input as item()?|xs:string}}<br/>{{Func|json:serialize|$input as item()?, $options as map(*)?|xs:string}}
+
|<pre>json:serialize(
|-
+
  $input   as item()?,
 +
  $options as map(*)? := map { }
 +
) as xs:string</pre>
 +
|- valign="top"
 
| '''Summary'''
 
| '''Summary'''
 
|Serializes the specified {{Code|$input}} as JSON, using the specified {{Code|$options}}, and returns the result as string:
 
|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 [[#json:parse|json:parse()]].
+
* 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.
 
* 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:
 
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 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.
 
* the options presented in this article need to be assigned to the {{Code|json}} parameter.
|-
+
|- valign="top"
 
| '''Errors'''
 
| '''Errors'''
 
|{{Error|serialize|#Errors}} the specified node cannot be serialized as JSON document.
 
|{{Error|serialize|#Errors}} the specified node cannot be serialized as JSON document.
Line 168: Line 175:
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
let $database := "database"
 
let $database := "database"
 
for $name in file:list('.', false(), '*.json')
 
for $name in file:list('.', false(), '*.json')
Line 174: Line 181:
 
let $json := json:parse($file)
 
let $json := json:parse($file)
 
return db:add($database, $json, $name)  
 
return db:add($database, $json, $name)  
</syntaxhighlight>
+
</pre>
  
 
'''Example 2: Converts a simple JSON string to XML and back'''
 
'''Example 2: Converts a simple JSON string to XML and back'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
json:parse('{}')
 
json:parse('{}')
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="xml">
+
<pre lang="xml">
 
<json type="object"/>
 
<json type="object"/>
</syntaxhighlight>
+
</pre>
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
(: serialize result as plain text :)
 
(: serialize result as plain text :)
 
declare option output:method 'text';
 
declare option output:method 'text';
 
json:serialize(<json type="object"/>)
 
json:serialize(<json type="object"/>)
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
{ }
 
{ }
</syntaxhighlight>
+
</pre>
  
 
'''Example 3: Converts a JSON string with simple objects and arrays'''
 
'''Example 3: Converts a JSON string with simple objects and arrays'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
json:parse('{
 
json:parse('{
 
   "title": "Talk On Travel Pool",
 
   "title": "Talk On Travel Pool",
Line 211: Line 218:
 
   "generator": "http://www.flickr.com/"
 
   "generator": "http://www.flickr.com/"
 
}')
 
}')
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="xml">
+
<pre lang="xml">
 
<json type="object">
 
<json type="object">
 
   <title>Talk On Travel Pool</title>
 
   <title>Talk On Travel Pool</title>
Line 222: Line 229:
 
   <generator>http://www.flickr.com/</generator>
 
   <generator>http://www.flickr.com/</generator>
 
</json>
 
</json>
</syntaxhighlight>
+
</pre>
  
 
'''Example 4: Converts a JSON string with different data types'''
 
'''Example 4: Converts a JSON string with different data types'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
let $options := map { 'merge': true() }
 
let $options := map { 'merge': true() }
 
return json:parse('{
 
return json:parse('{
Line 249: Line 256:
 
   ]
 
   ]
 
}', $options)
 
}', $options)
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="xml">
+
<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 273: Line 280:
 
   </phone>
 
   </phone>
 
</json>
 
</json>
</syntaxhighlight>
+
</pre>
  
 
==JsonML Format==
 
==JsonML Format==
Line 280: Line 287:
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<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, map { 'format': 'jsonml' })
 
let $json := json:serialize($doc, map { 'format': 'jsonml' })
 
return file:write($name, $json)
 
return file:write($name, $json)
</syntaxhighlight>
+
</pre>
  
 
'''Example 2: Converts an XML document with elements and text'''
 
'''Example 2: Converts an XML document with elements and text'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
json:serialize(doc('flickr.xml'), map { 'format': 'jsonml' })
 
json:serialize(doc('flickr.xml'), map { 'format': 'jsonml' })
</syntaxhighlight>
+
</pre>
  
 
'''flickr.xml:'''
 
'''flickr.xml:'''
<syntaxhighlight lang="xml">
+
<pre lang="xml">
 
<flickr>
 
<flickr>
 
   <title>Talk On Travel Pool</title>
 
   <title>Talk On Travel Pool</title>
Line 303: Line 310:
 
   <generator>http://www.flickr.com/</generator>
 
   <generator>http://www.flickr.com/</generator>
 
</flickr>
 
</flickr>
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="json">
+
<pre lang="json">
 
["flickr",
 
["flickr",
 
   ["title",
 
   ["title",
Line 318: Line 325:
 
   ["generator",
 
   ["generator",
 
     "http://www.flickr.com/"]]
 
     "http://www.flickr.com/"]]
</syntaxhighlight>
+
</pre>
  
 
'''Example 3: Converts a document with nested elements and attributes to JsonML'''
 
'''Example 3: Converts a document with nested elements and attributes to JsonML'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
json:serialize(doc('input.xml'), map { 'format': 'jsonml' })
 
json:serialize(doc('input.xml'), map { 'format': 'jsonml' })
</syntaxhighlight>
+
</pre>
  
 
'''input.xml:'''
 
'''input.xml:'''
<syntaxhighlight lang="xml">
+
<pre lang="xml">
 
<address id='1'>
 
<address id='1'>
 
   <!-- comments will be discarded -->
 
   <!-- comments will be discarded -->
Line 340: Line 347:
 
   <phone type='home'>212 555-1234</phone>
 
   <phone type='home'>212 555-1234</phone>
 
</address>
 
</address>
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="json">
+
<pre lang="json">
 
["address", {"id":"1"},
 
["address", {"id":"1"},
 
   ["last_name",
 
   ["last_name",
Line 358: Line 365:
 
   ["phone", {"type":"home"},
 
   ["phone", {"type":"home"},
 
     "212 555-1234"]]
 
     "212 555-1234"]]
</syntaxhighlight>
+
</pre>
  
 
==XQuery Format==
 
==XQuery Format==
Line 365: Line 372:
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
let $input := '{
 
let $input := '{
 
   "Title": "Drinks",
 
   "Title": "Drinks",
Line 374: Line 381:
 
   $k || ': ' || string-join($v, ', ')
 
   $k || ': ' || string-join($v, ', ')
 
})
 
})
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="json">
+
<pre lang="json">
 
Author: Jim Daniels, Jack Beam
 
Author: Jim Daniels, Jack Beam
 
Title: Drinks
 
Title: Drinks
</syntaxhighlight>
+
</pre>
  
 
'''Example 2: Converts XQuery data to JSON'''
 
'''Example 2: Converts XQuery data to JSON'''
  
 
'''Query:'''
 
'''Query:'''
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
for $item in (
 
for $item in (
 
   true(),
 
   true(),
Line 396: Line 403:
 
   map { 'format': 'xquery', 'indent': 'no' }
 
   map { 'format': 'xquery', 'indent': 'no' }
 
)
 
)
</syntaxhighlight>
+
</pre>
  
 
'''Result:'''
 
'''Result:'''
<syntaxhighlight lang="json">
+
<pre lang="json">
 
true
 
true
 
"ABC"
 
"ABC"
 
[1,2,3,4,5]
 
[1,2,3,4,5]
 
{"Key":"Value"}
 
{"Key":"Value"}
</syntaxhighlight>
+
</pre>
  
 
=Errors=
 
=Errors=
Line 411: Line 418:
 
! width="110"|Code
 
! width="110"|Code
 
|Description
 
|Description
|-
+
|- valign="top"
 
|{{Code|options}}
 
|{{Code|options}}
 
|The specified options are conflicting.
 
|The specified options are conflicting.
|-
+
|- valign="top"
 
|{{Code|parse}}
 
|{{Code|parse}}
 
|The specified input cannot be parsed as JSON document.
 
|The specified input cannot be parsed as JSON document.
|-
+
|- valign="top"
 
|{{Code|serialize}}
 
|{{Code|serialize}}
 
|The specified node cannot be serialized as JSON document.
 
|The specified node cannot be serialized as JSON document.
Line 423: Line 430:
  
 
=Changelog=
 
=Changelog=
 +
 +
;Version 10.0
 +
* Updated: {{Code|indent}}: Default changed from {{Code|yes}} to {{Code|no}}.
  
 
;Version 9.4
 
;Version 9.4
* Added: [[#json:doc|json:doc]]
+
* Added: {{Function||json:doc}}
  
 
; Version 9.1
 
; Version 9.1
* Updated: [[#json:parse|json:parse]] can be called with empty sequence.
+
* Updated: {{Function||json:parse}} can be called with empty sequence.
  
 
;Version 9.0
 
;Version 9.0
Line 450: Line 460:
  
 
;Version 7.7.2
 
;Version 7.7.2
* Updated: {{Code|$options}} argument added to [[#json:parse|json:parse]] and [[#json:serialize|json:serialize]].
+
* Updated: {{Code|$options}} argument added to {{Function||json:parse}} and {{Function||json:serialize}}.
* Updated: [[#json:parse-ml|json:parse-ml]] and [[#json:serialize-ml|json:serialize-ml]] are now ''deprecated''.
+
* 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 17:38, 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.

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 a name 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:
  • If a name has the same type throughout the data, the 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.
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:
  • The input is expected to conform to the results that are created by json:parse.
  • Non-conforming items will be serialized as specified in the json output method of the official recommendation.

Values can also be serialized as JSON with the standard Serialization feature of XQuery:

  • The parameter method needs to be set to json, and
  • the options presented in this article need to be assigned to the json parameter.
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 from yes to no.
Version 9.4
Version 9.1
  • Updated: json:parse can be called with empty sequence.
Version 9.0
  • Updated: map format renamed to xquery.
  • Updated: error codes updated; errors now use the module namespace
Version 8.4
  • Updated: unescape changed to escape.
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 if format is set to .map.
Version 7.7.2

The module was introduced with Version 7.0.