Hands on JSON

Hands on JSON

• 1.
  Hands on JSON © 2019Syncro Soft SRL. All rights reserved. Octavian Nadolu, Syncro Soft octavian_nadolu@oxygenxml.com @OctavianNadolu
• 2.
  Hands on JSON SoftwareArchitect at Syncro Soft octavian.nadolu@oxygenxml.com • 15+ years of XML technology experience • Contributor for various XML-related open source projects • Editor of Schematron QuickFix specification developed by a W3C community group About me
• 3.
  Hands on JSON Agenda ● JSONDocuments Structure ● Validating JSON Documents ● Querying and Transforming JSON Documents ● Converting JSON Documents
• 4.
  Hands on JSON JSON (JavaScriptObject Notation) ● Data representation format ● Used for API and Configs ● Lightweight and easy to read/write http://json.org
• 5.
  Hands on JSON JSONDocuments Structure ● JSON Data – name/value pair ● JSON Object {...} ● JSON Array [...]
• 6.
  Hands on JSON JSONData ● A collection of name/value pairs ● The name in double quotes, followed by a colon, followed by a value ”firstname”: ”Jane”
• 7.
  Hands on JSON Value {...},[...], 2, "one", true, null
• 8.
  Hands on JSON Object {”firstname”:”Jane”, ”lastname": ”Doe”}
• 9.
  Hands on JSON Array [{”firstname”:”Jane”, ”lastname": ”Doe”}, {”firstname”: ”John”, ”lastname": ”Jones”}]
• 10.
  Hands on JSON Example { "persons":[ { "id": "jane.doe", "firstname": "Jane", "lastname": "Doe", "email": "jane@oxygenxml.com", "age": 37 }, { "id": "john.jones", "firtname": "John", "lastname": "Jones", "email": "john@oxygenxml.com", "age": 42 } ] } Object Array Property Value
• 11.
  Hands on JSON ValidatingJSON Documents ● Checking Well-Formedness in JSON Documents ● Validating JSON Documents Against JSON Schema ● Validating JSON Schema According to the Specification
• 12.
  Hands on JSON CheckingWell-Formedness Check if the JSON document respects the JSON specification { "id": "jane.doe", "firstname": "Jane", "lastname": "Doe", "email": "jane@oxygenxml.com", "age": 37 } ECMA-404 The JSON Data Interchange Standard http://json.org/
• 13.
  Hands on JSON Example { "persons"[ { "id": "jane.doe", "firstname": "Jane", "lastname": "Doe", "email": "jane@oxygenxml.com" "age": 37, }, { "id": "john.jones, "firtname": "John", "lastname": "Jones", "email": "john@oxygenxml.com", "age": 42 ] } Expected ',' character Unexpected ',' character Expected a ':' after a key Expected quotes Expected '}'
• 14.
  Hands on JSON JSONSchema JSON Schema is a vocabulary that allows you to annotate and validate JSON documents http://json-schema.org
• 15.
  Hands on JSON DefiningJSON Schema ● Similar to XML Schema, RNG, or DTD ● Written in JSON ● Used to define the structure of a JSON data {”type”: ”string”} JSON Schema ”I'm a string” JSON Instance
• 16.
  Hands on JSON Example JSONSchema { "type": "object", "properties": { "persons": { "type": "array" } } } JSON Instance { "persons": [ ] }
• 17.
  Hands on JSON Example JSONSchema { "type": "object", "properties": { "persons": { "type": "array", "items": { "type": "object", "properties": { "id": {"type": "string"}, "firstname": {"type": "string"}, "lastname": {"type": "string"}, "email": {"type": "string","format": "email"}, "age": {"type": "number"} } } } } } JSON Instance { "persons": [ { "id": "jane.doe", "firstname": "Jane", "lastname": "Doe", "email": "jane@oxygenxml.com", "age": 37} ] }
• 18.
  Hands on JSON JSONSchema Definition ● It is recommended to to have the schema definition on the first level "$schema": "http://json-schema.org/draft-07/schema#" ● JSON Schema used versions: – Draft 4 – Draft 6 – Draft 7 – Draft 8
• 19.
  Hands on JSON Validatingwith JSON Schema ● Check if the JSON instance respects the definitions { "persons": [ { "id": 2, "firstname": "Jane", "familyname": "Doe", "email": "jane@oxygenxml..com", "age": 37 } ] } Invalid email address Expected string, but fund integer Required key [lastname] not found [familyname] is not permitted
• 20.
  Hands on JSON AssociateJSON Schema ● Associating a Schema to JSON Documents – Directly in JSON document – using $schema property – In application options { "$schema": "person-schema.json", "persons" [ ... ] } Absolute or relative URI
• 21.
  Hands on JSON ValidatingJSON Schema ● Check for well-formedness ● Validate accordingly to the Internet Engineering Task Force (IETF) Specification
• 22.
  Hands on JSON ValidatingJSON with Schematron ● Specify the JSON structure using JSON Schema ● Express co-constraints and define custom rules using Schematron
• 23.
  Hands on JSON Schematronfor JSON ● Use XPath to express the rules <sch:rule context="persons"> <sch:assert test="number(age) > preceding-sibling::node()/age "> The person age must be grater than the previous person age </sch:assert> </sch:rule>
• 24.
  Hands on JSON Schematronusing JSONPath ● Schematron reimagined for JSON with no whiff of XML/XPath ● Moved out of the XPath and use JSONPath https://github.com/amer-ali/jsontron "rule": [ {"context": "$.persons.*", "assert": [ {"test": "(jp.query(contextNode,'$..age') >= 21", "message": "The person age must be grater than 21"} ] } ]
• 25.
  Hands on JSON Queryingand Transforming ● Query using JSON Pointer, JSONiq, or XPath ● Transform JSON using JavaScript, XSLT, XQuery
• 26.
  Hands on JSON JSONPointer Used to identify a specific value within a JSON document #/persons/0/email Matches first person email Specification https://tools.ietf.org/html/rfc6901
• 27.
  Hands on JSON JSONiq Aquery and processing language for JSON www.jsoniq.org
• 28.
  Hands on JSON XPath ● Powerfullanguage for queering XML documents ● Was adopted by applications also for JSON /persons[2]/email Matches second person email
• 29.
  Hands on JSON ProcessJSON with JavaScript ● Most popular way to process JSON documents ● Multiple libraries var json = '{"name":”John Doe”, "age":42}'; obj = JSON.parse(json); console.log(obj.name); // Result John Doe console.log(obj.age); // Result 42
• 30.
  Hands on JSON Transformusing XSLT/XQuery ● Transform JSON Documents to Different Formats ● Different functions to process JSON document: ● json-doc($href as xs:string?) as item()? ● json-to-xml($json-text as xs:string?) as document-node()?
• 31.
  Hands on JSON ConvertingJSON Documents ● JSON to XML and XML to JSON ● Convert using XSLT ● Online Converters
• 32.
  Hands on JSON JSONto XML { "personnel": { "person": [ { "id": 1, "name": { "family": "Worker", "given": "One" }, "email": "one@oxygenxml.com", "link": {"manager": "Big.Boss"} }, { "id": 2, "name": { "family": "Worker", "given": "Two" }, "email": "two@oxygenxml.com", "link": {"manager": "Big.Boss"} } ] } } <personnel> <person> <id>1</id> <name> <family>Worker</family> <given>One</given> </name> <email>one@oxygenxml.com</email> <link> <manager>Big.Boss</manager> </link> </person> <person> <id>2</id> <name> <family>Worker</family> <given>Two</given> </name> <email>two@oxygenxml.com</email> <link> <manager>Big.Boss</manager> </link> </person> </personnel>
• 33.
  Hands on JSON JSONto XML Conversion Details ● A <JSON> element is added as root if the converted JSON has multiple properties on the first level ● An <array> element is added as root if the converted JSON is an array [ {"name": "Boss"}, {"name": "Worker"} ] <array> <array> <name>Boss</name> </array> <array> <name>Worker</name> </array> </array> { "person": "one", "id": "personnel-id" } <JSON> <person>one</person> <id>personnel-id</id> </JSON>
• 34.
  Hands on JSON 1 XMLto JSON <personnel> <person id="1"> <name> <family>Worker</family> <given>One</given> </name> <email>one@oxygenxml.com</email> <link manager="harris.anderson"/> </person> <person> <id>2</id> <name> <family>Worker</family> <given>Two</given> </name> <email>two@oxygenxml.com</email> <link manager="harris.anderson"/> </person> </personnel> { "personnel": { "person": [ { "id": 1, "name": { "family": "Worker", "given": "One" }, "email": "one@oxygenxml.com", "link": {"manager": "harris.anderson"} }, { "id": 2, "name": { "family": "Worker", "given": "Two" }, "email": "two@oxygenxml.com", "link": {"manager": "harris.anderson"} } ] } }
• 35.
  Hands on JSON XMLto JSON Conversion Details ● XML attributes are converted to properties <person id="1"/> {"person": {"id": 1}} ● Multiple elements with the same name are converted into an array <person/> <person/> "person": ["",""] ● Text in mixed content will be converted in a #text property <p>This is an <b>example</b>!</p> p": {"#text": "This is an","b": "example","#text1": "!"}
• 36.
  Hands on JSON Convertusing XSLT ● Library that converts XML to JSON using XSLT https://github.com/bramstein/xsltjson XSLT Specification for JSON http://www.w3.org/TR/xslt-30/#json
• 37.
  Hands on JSON OnlineConverter ● Online XML to JSON Converters Convert between XML and JSON
• 38.
  Hands on JSON Conclusion ● JSONconforms to ECMA/ISO specification ● Validate JSON with JSON Schema ● Query and process JSON using JSON Pointer, JSONiq, XPath, or JavaScript and XSLT ● Conversions to convert between JSON and XML
• 39.
  Questions? Octavian Nadolu Software Architectat Syncro Soft octavian.nadolu@oxygenxml.com Twitter: @OctavianNadolu LinkedIn: octaviannadolu https://sundt01.honestly.de