OSW Schema

OSW Schema ID: OSWab674d663a5b472f838d8e1eb43e6784 | UUID: ab674d66-3a5b-472f-838d-8e1eb43e6784 | 📦: world.opensemantic.meta.docs.core
ID	OSWab674d663a5b472f838d8e1eb43e6784
UUID	ab674d66-3a5b-472f-838d-8e1eb43e6784
Label	OSW Schema
Machine compatible name	OswSchema
Types/Categories	Article
Statements (outgoing)
Statements (incoming)
Details
Types/Categories<br>Definition: Entity, Item, Creative Work, Article: Article Label(s)At least one label is required.<br>Definition: Entity: OSW Schema Description<br>Definition: Entity: Documentation about to OSW data schema File attachments<br>Definition: Entity: File:OSW2f275e3441c84f63a6cbee2861c488f2.drawio.svg;File:OSW49d68bb7a5de413ba1077bc5f459a766.drawio.svg;File:OSW61f1999ee6d145c9b76fb55d02578ce5.drawio.svg;File:OSW95a74be1e22d4b6e9e4f836127d5915a.drawio.svg;

Description

Documentation about to OSW data schema

Item
Type(s)/Category(s)	Article

Schema for the dynamical Composition of nested class structures

Introduction

Transforming Semantic Mediawiki into a knowledge base with structured data used to require PageForms and multiple template per class:

• Template to store the data and render the page
• Form to edit the page
• Form to query for instances of the class
• Template to render the query results
• Subtemplate to handle complex data

Reusing structures with this approach is difficult and storing data in wikicode leads to a significant lock-in regarding editing those data using existing stardards and tools.

The new concept is based on strictly storing data in json and use wikicode just for structured text and render templates. Insteaf of distributing content among multiple pages all relevent content is stored withing different slots of the same page. Additional, inheritance is highly supported and enables a broad reuse of any structure.

Overview

General

Diagram OSW concept and included technologies

Diagram diagram-01

Dual hierarchy example

Why are Categories (Classes) different from Items (Instances)?

• Pro
  • Reflects rdf(s) and owl standard
  • Reflects OOP in Python and other programming languages, only (?) Javascript supports a similar concepts with prototypes
  • Compatible with SMW features like rdf-export and Inferencing
• Contra
  • User needs to decide before creating a term or move the term later to a different namespace (renaming/redirect)

Slots

Slots

Key	Model	Description
main	wikitext	default content slot, rendered between the page header and footer
jsonschema	json	stored within a category (=class) page, defining the schema for the jsondata slot of any category member (instance)
jsondata	json	structured data
schema_template	text	stored within a metacategory/-class, contains a handlebars template to build the jsonschema of a class from its jsondata slot
data_template	wikitext	stored within a category (=class) page, defining how the jsondata attributes of any category member (instance) are mapped to semantic properties
header_template	wikitext	stored within a category (=class) page, renders the page header of any category member (instance)
footer_template	wikitext	stored within a category (=class) page, renders the page footer of any category member (instance)
header	wikitext	renders the page header
footer	wikitext	renders the page footer
template/internal	wikitext	hidden content, not rendered. Can be used to call parser functions or lua modules

Meta-Schemas

Category (Class) ist the default Metacategory / -class for all categories / classes. Its slot schema_template contains a handlebars template that sets schema attributes like title, allOf, description, etc. from the user generated jsondata. Additional Metacategories can be created as subclasses of Category (Class) to simplify the creation of complex schemas, e. g. Category:OSWecff4345b4b049218f8d6628dc2f2f21. This feature is compareable to python metaclasses.

Diagram meta-schema

Matecategories /-classes contain a handlebars template within the schema_template slot. The templated is evaluated with the jsondata-slot content to create / update the jsonschema-slot content of any derivated class on every edit. #Handlebars_Template_Helper and #Special_Template_Variables apply here.

Json-Schema

Diagram diagram-json

Base

https://json-schema.org/ (Draft 4)

A Jsonschema can reference other schemas. This is equivalent to [[Subcategory of::Entity]] (Semantic Mediawiki) and owl:subclass_of

{
    "title": "MyEntitySubclass",
    "type": "object",
    "allOf": [{"$ref": "../Category/Entity.slot_jsonschema.json"}]
}

Note: refs were previously noted as "/wiki/Category:Entity?action=raw&slot=jsonschema"but this notation only works if /wiki is actually the root path of the system. Path-relative notations (./)Category:Entity and url-params are problematic so initial absolute and subsequent relative resolving is done via Special:SlotResolver, e. g. Special:SlotResolver/JsonSchema/Label.slot_main.json or Special:SlotResolver/Category/Entity.slot_jsonschema.json. To reuse a schema in an external tool you can use e. g. "$schema": "https://opensemantic.world/wiki/Special:SlotResolver/Category/Entity.slot_jsonschema.json"

Json-Editor

https://github.com/json-editor/json-editor, which is used to render edit & query forms based on provided jsonschema, adds additional keywords and options.

• Basic features: see https://github.com/json-editor/json-editor#readme
• Further details: https://github.com/json-editor/json-editor/blob/master/README_ADDON.md
• Demos: https://json-editor.github.io/json-editor/, https://pmk65.github.io/jedemov2/dist/demo.html
• Examples: https://github.com/json-editor/json-editor/tree/master/tests/pages

Autocompletion

• https://github.com/trevoreyre/autocomplete
• https://github.com/corejavascript/typeahead.js/blob/master/doc/jquery_typeahead.md (currently not supported)

Enables autocompletion in input fields. Configuration see Additional options

Custom Extensions

Embedded i18n support:

keywords title and description can be extended with additional keywords title* and description*, which hold and object with lang-keys (de, en, etc.) pointing to the translated strings.

{
    "title": "Default Title",
    "title*": {"en": "Title (en)", "de": "Titel (de)"}
}

Property Order

Extending json-editors definition, propertyOrder can be set to the render order of properties in the edit form. In general smaller values are on the top, larger values below. The value range 0 - 1000 is reserved for the local order of properties within the same schema. Values < 0 will move the property globally on top, values > 1000 globally to the bottom of the form. See also implementation.

Handlebars Template Helper

Whenever templates are supported, the following custom handlebars helpers are supported as well:

Key	Syntax	Example	Example result	Description	Comment
when	{{#when <operand1> <operator> <operand2>}}...{{/when}}	{{#when 2 'eq' 1}}equal{{else when var1 'gt' var2}}gt{{else}}lt{{/when}}	gt	compare operator	Supported operators: see implementation
replace	{{#replace <find> <replace>}}{{string}}{{/replace}}	{{#replace "test" "test2"}}_test_{{/replace}}	_test2_	string replace operator
split	{{#split <find> <index>}}<string>{{/split}}	{{#split "/" -1}}https://test.com/target{{/split}}	target	string split operator
each_split	{{#each_split <string> <find>}}...{{/each_split}}	{{#each_split "https://test.com/target" "/"}}{{.}},{{/each_split}}	https:,,test.com,target,	split result iterator
substring	{{#substring start end}}<string>{{/substring}}	{{#substring 0 -2}}My-test-string{{/substring}} => My-test-stri	My-test-stri	substring operator	negative indices are supported (counted from end-of-string)
calc	{{calc <operand1> <operator> <operand2>}} or {{#calc <operand1> <operator>}}<operand2>{{/calc}}	a={{calc (calc 1 '+' 1) '*' 10}} b={{#calc 3 '*'}}2{{/calc}}	a=20 b=6	math callback
patternformat	{{#patternformat <pattern>}}<string>{{/patternformat}} or {{patternformat <pattern> <value>}}	{{patternformat '00.0000' '1.1' }}	01.1000	pattern formator for both numbers and strings
dateformat	{{dateformat <format> <date>}}	{{dateformat 'Y' (_now_)}}	2024	formats a datetime value	supported formats: https://flatpickr.js.org/formatting/
_uuid_	{{_uuid_}}	{{_uuid_}}	ad56b31f-9fe5-466a-8be7-89bce58045f1	uuidv4
_now_	{{_now_}}	{{_now_}}	2024-02-04T04:31:08.050Z	current datetime	iso-format

Note on helper and param naming collision: When a helper has the same name as a key in the json params, the helper is prioritized. However, you can use this.<param> to enforce the param over the helper.[1]

Example: helper 'test' returns 'helper', json data is {"test": "param"}.

Template "{{test}} {{#test}}{{/test}} {{this.test}}" will be evaluated to helper helper param

Note on escaping curly brackets: You can escape single blocks, e.g. \{{escaped}} \{{also_escaped}} {{not_escaped}} will be evaluated to {{escaped}} {{also_escaped}} some value... .[2]

Special Template Variables

Available in format: dynamic_template

Variable	Description	Example	Example result	Note
_current_user_	The identity of the current active user	{{{_current_user_}}}	User:MyUserName
_current_subject_	The title / OSW-ID of the current page / entry	{{{_current_subject_}}}	Item:OSWab674d663a5b472f838d8e1eb43e6784
_array_index_	The index of an array item within its parent array	{{{_array_index_}}}	1
_global_index_	Retrieves the smallest non-existing prefixed index for values of the specified property (default: Property:HasId). See also Additional options / global_index	ID-{{{_global_index_}}}	Existing entries: "HasId::ID-0001", "HasId::ID-0002", "HasId::ID-0003" Template resolves to "ID-0004"

Available in slot schema_template:

Variable	Description	Example	Example result	Note
_page_title	The title / OSW-ID of the current page / entry	{{{_page_title}}}	Category:Entity	deprecated, use _current_subject_
_current_subject_	The title / OSW-ID of the current page / entry	{{{_current_subject_}}}	Category:Entity	replaces _page_title
self	The template itself as partial	{ "name": "Object", "subobjects": [{ "name": "Subobject", "subobjects": [{ "name": "Subsubobject", "subobjects": "..." }] }] } name: {{name}} {{#each subobject}} {{> self}} {{/each}}	name: Object name: Subobject name: Subsubobject ...	allows recursive templates, see also https://handlebarsjs.com/guide/partials.html

Additional keywords

Special jsonschema attributes ($properties.<property>.*)

Key	Alias	Subkeys	Value	Description	Note
range	-	-	<category>	range of a property in the sense of OWL restricting the class(es) the pointed item could be instance of. Currently supports only a single string. Multiple categories connected with AND or OR: tbd	Also used to generate a suitable inline editor to create or edit these items (see also $properties.<property>.options.autocomplete)
template			<string>	handlebars template string. Available variables: watched values	Build-in
dynamic_template				handlebars template string. Available variables: watched values	Extended template feature
eval_template				evaluation template for the current json object (while 'template' is used by jsoneditor in the UI)	eval_templates are expanded before the json data is passed to render templates and property mapping
		type	mediawiki	uses the wiki template parser. Cannot handle objects and arrays => non-literals get stripped
		"	mustache	uses the lua mustache template parser https://github.com/OpenSemanticLab/lustache/tree/scribunto-module-pages. Can handle objects and arrays	https://mustache.github.io/, https://stackblitz.com/edit/mustache-tester?file=index.js
		"	mustache-wikitext	applies mustache first, then wikitext	wikitext parts containing {{ need to be wrapped inside {{=<% %>=}} and<%={{ }}=%>
		mode	<none>	the given template will be used to render the json object and store it's semantic data
		"	render	the given template will be used to render the json object
		"	store	the given template will be used to store semantic data
		value	<string>	the template string
data_source_maps				see section "Remote / external data import"

Note on default rendering in infoboxes:

• Properties of @type xds:date and xsd:dateTime are rendered with {{dateformat: {{value}} | ymd}}, see https://www.mediawiki.org/wiki/Help:Magic_words#dateformat
• Properites of @type @id are rendered as links as long as they are (arrays of) string literals and no eval_template is defined.

Special jsondata attributes ($.*)

Key	Alias	Subkeys	Value	Description	Note
type		-	an array of category pages	if defined, the given category will be used to render the json object and store it's semantic data

Additional options

Additional options ($properties.<property>.options.*)

Key	Subkeys	SubSubkeys	Value	Example	Description	Note
conditional_visible
	modes		<array>	["default", "query"]	Display this field only in the selected modes of the editor
conditional_hide					tbd
range			string	"Category:Item"	Shortcut for a static query [[Category:Item]][[Display_title_of_normalized::~*{{_user_input_normalized}}*]]|?... . Creates an inline editor for the given category
subclassof_range			string	"Category:Device"	Indicates that the target are subclasses of the given device. Inline editor will use the meta class of the given category, e. g. "Category:MetaDeviceCategory", or will use the range if given
autocomplete					buildin option
	mode		smw		query mode	for now only supports semantic mediawiki
	query			[[HasLabel::~*{{_user_input}}*]]|?HasLabel=label	handlebars query template. Available are all keys of the current schema and _user_input, _user_input_lowercase, _user_input_normalized, _user_lang	|?Display_title_of=label,             |?HasImage=image, |?HasDescription=description and |limit=100 are appended automatically if not specified
	category			Category:Item	creates a static query [[Category:Item]][[Display_title_of_normalized::~*{{_user_input_normalized}}*]]|?.... Creates an inline editor for the given category	see also $properties.<property>.range
	property			Property:HasLabel	query entities with existing value of the specified property [[HasLabel::+]][[Display_title_of_normalized::~*{{_user_input_normalized}}*]]?...
	render_template				how to display query results in the suggestion list
		type	<array>	["handlebars", "wikitext"]	template engines are applied in the specified order. wikitext will result in parse-API calls, which is not recommanded for large result sets
		value	template string	[[{{result.fulltext}}]]	the actual template string. Pure handlebars templates can contain html tags like links (<a>) and images (<img>), wikitext templates need to use the wiki-syntax [[ ]]	wiki-links to categories need a : prefix: [[:{{result.fulltext}}]]
	label_template				how to display the item after getting selected by the user
		type	<array>	["handlebars"]	only handlebars supported
		value	template string	result.printouts.label.[0]
	field_maps				Auto-set editor fields based on the SMW ask-API query result. Example: JsonSchema:QuantityStatement
		source_path	<jsonpath>	"$"	jsonpath to apply on the query result
		template	template string	"{{{result.printouts.label.[0]}}}"	optional handlebars template applied on the json-object retrieved from the source path of the query result
		target_path	<jsonpath>	"$(unit_symbol)"	jsonpath of the target field in the editor. You can use jsoneditors watch variables (recommended) to auto-generate the expression
dynamic_template					options for dynamic_template
	override	<enum value>	unstored|empty|always	always	Allow the template to override the current value of the field if the current value is undefined or an empty string (empty), was not yet stored (unstored) or always. dynamic_templates with _global_index_ default to unsafed (=> do not update the value after initial stored), user editable fields (not hidden and not readonly => only set an initial default) to emtpy, else always is used.
global_index
	property		<property name>	Property:HasId	The Property to determine the next lowest index of a prefixed value within the dynamic_template option. Currently hardcoded to Property:HasId
	number_pattern		<string>	0000	The pattern of the index. Index = 2, pattern = 0000 => 0002. Currently hardcoded to 0000
	increment		<numver>	1	The increment of the index. Currently hardcoded to 1
role	query		{"filter": "min|max|eq"}	{"filter": "min"}	Creates a semantic mediawiki query for a numerical property, e. g. if the property maps to "HasNumber", the filter is "min" and the user provided value is 3 this results in the query ">3Property "HasNumber" (as page type) with input value ">3" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process."

Autocomplete

Default setting (planned, see also Object Properties and Data / Annotation Properties)

• for data / annotation properties: existing values of the property: {{#ask:[[<Property>::+]]|?<Property>=value}}
• for object properties: existing instances of the range category: {{#ask:[[Category:<range>]]}}

Shortcuts

• category: Populates the field with instances of the given category (and its subcategories)

{
    "type": "string",
    "format": "autocomplete",
    "options":{	
        "autocomplete": {
            "category":"Category:X"
        }
    }
}

Reverse properties

There are many cases were relation are summetric, e.g. Organization employees Person <=> Person worksFor Organization.

However, usually we do not want to store this information in different schemas but allow users to edit it from both sides.

For this usecase the additional keywords x-oold-reverse-properties, x-oold-reverse-default-properties and x-oold-reverse-required are introduced

To make employees the reverse property of organization we have to

• define employees in the schema section x-oold-reverse-properties of Organization
• define works_for in the schema section x-oold-reverse-properties of Person
• map employees to a semantic property, e.g. Property:worksFor in the @context of Person
• map employees with @reverse in the @context of Organization to the same property, compliant to JSON-LD @reverse

When loading the editor for an Organization, the editor will now prepopulate the field employees by executing the query "Which persons work for this organization"?

When storing an Organization, the editor will also load the Persons referenced in employeesand stores the current Organization in their organization field, following the @context mappings of both schemas.

Deleting a Person in employees will also delete the Organization from the corresponding field.

Example

Category:Organization

{
  "@context": [
    {
      "employees": {
        "@reverse": "Property:WorksFor",
        "@type": "@id"
      }
    }
  ],
  "title": "OrganizationalUnit",
  "uuid": "3cb8cef2-225e-4030-92f0-98f99bc4c472",
  "id": "OSW3cb8cef2225e403092f098f99bc4c472",
  "type": "object",
  "required": [
    "type"
  ],
  "properties": {
    "...": {}
  },
  "x-oold-reverse-required": [],
  "x-oold-reverse-defaultProperties": [
    "employees"
  ],
  "x-oold-reverse-properties": {
    "employees": {
      "type": "array",
      "title": "Employees",
      "items": {
        "type": "string",
        "format": "autocomplete",
        "title": "Person",
        "$comment": "range is Person",
        "range": "Category:OSW44deaa5b806d41a2a88594f562b110e9"
      }
    }
  }
}

Category:Person

{
  "@context": [
    {
      "organization": {
        "@id": "Property:WorksFor",
        "@type": "@id"
      }
    }
  ],
  "title": "Person",
  "type": "object",
  "uuid": "44deaa5b-806d-41a2-a885-94f562b110e9",
  "defaultProperties": [
    "organization"
  ],
  "properties": {
    "organization": {
      "title": "Organization",
      "description": "Organization(s) the person is affiliated with. E.g., university, research institute, company, etc.",
      "type": "array",
      "format": "table",
      "items": {
        "type": "string",
        "title": "Organization",
        "format": "autocomplete",
        "range": "Category:OSW3cb8cef2225e403092f098f99bc4c472"
      }
    }
  }
}

Remote / external data import

Key	Alias	Subkeys	SubSubkeys	Value	Example	Description	Note
data_source_maps	-					To fetch data from an external source (by user request) and store it in the edit form
		id		<string>	pub.orcid.org
		label		<string>	ORCID	Label for the data source, displayed on the request button
		required		<array>	["orcid"]	Properties of the schema that are required to send the request (typically those occure as template params in source	the request button is disabled if required properties are missing
		source		<url>	https://pub.orcid.org/v3.0/{{#split '/' -1}}{{orcid}}{{/split}}	API endpoint to fetch data	supports templates. API must allow request from a foreign domain
		format		<enum>	jsonld	The format of the requested resource. One of json (default), jsonld, xml, html	Used to set the correct contentType header field and parse the result
		mode		<enum>	jsonpath	The format of the path expression in the object_map. One of jsonpath (default for json, jsonld), xpath (default for xml, html)
		object_map		<dict>	{"first_name": "$.givenName"}	Stores the result of the path expression value (right-hand, evaluated on the API result) in the given key (left-hand)	Result of the path expression can be an array or object.
		template_map		<dict>		Constructs a value from a handlebars template (left-hand) and asigns it to the given key (right-hand)	tbd
		request_map					tbd
		map					tbd

{
    "...": {},
    "data_source_maps": [
        {
            "id": "pubchem.ncbi.nlm.nih.gov",
            "source": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/{{pubchem_cid}}/JSON",
            "label": "PubChem",
            "required": [
                "pubchem_cid"
            ],
            "object_map": {
                "cas_numbers": "$..[?(@.TOCHeading==='CAS')].Information..Value.StringWithMarkup..String"
            }
        }
    ],
    "properties": {
        "pubchem_cid": {
            "title": "PubChem CID",
            "type": "string"
        },
        "cas_numbers": {
            "type": "array",
            "...": {}
        },
        "...": {}
    }
}

Tests could be run on various playgrounds:

• Handlebars template: [3]

• jsonpath: [4]
• xpath: [5]

Search

Properties can be marked as inputs for the categories query form by adding the conditional_visible option. Therefor a context mapping to a SWM Property is mandatory (see #JSON-LD). With "hidden": true the property is only visible in the query form. With "hidden": false it's visible both in the edit and in the query form.

{
    "@context":
        "...",
        {
            "query_label": "Property:HasLabel"
        }
    ],
    "...": {},
    "properties": {
        "query_label": {
            "type": "string",
            "options": {
                "hidden": true,
                "conditional_visible": {
                    "modes": [
                        "query"
                    ]
                }
            }
        }
    }
}

The default comperator for text properties is ~ (like), for all other properties = (equal). The comperator can be defined with the role filter option, e. g. "min" for >.

{
    "@context": [
        {
            "start_date_min": "Property:HasStartDateAndTime"
        }
    ],
    "...": "...",
    "properties": {
        "start_date_min": {
            "type": "string",
            "format": "datetime-local",
            "options": {
                "flatpickr": {},
                "conditional_visible": {
                    "modes": "query"
                },
                "role": {
                    "query": {
                        "filter": "min"
                    }
                }
            }
        }
    }
}

JSON-LD

json-ld jsonschema: https://github.com/json-ld/json-ld.org/blob/main/schemas/jsonld-schema.json

Local playground: https://wiki-dev.open-semantic-lab.org/w/extensions/MwJson/json-ld/playground/index.html

References

json-ld should be embedded into jsonschema, but has its own referencing mechanism:

{
    "@context": [
        "../Category/Entity.slot_jsonschema.json",
        {
            "Property": {"@id": "https://wiki-dev.open-semantic-lab.org/id/Property-3A", "@prefix": true},
            "manufacturer": "Property:HasManufacturer"
        }
    ],
    "title": "MyEntitySubclass",
    "type": "object",
    "allOf": [{"$ref": "../Category/Entity.slot_jsonschema.json"}],
    "properties": {
        "manufacturer": {
            "type": "string"
        }
    }
}

Example: [6]

For a remote context the same mechanism are used as in json-schema $refs. To reuse a context in external tools you can use e. g. "@context": "https://opensemantic.world/wiki/Special:SlotResolver/Category/Entity.slot_jsonschema.json" .

Property mapping

Properties with a local definition (SMW Property) are automatically mapped. Jsondata of an instance of the category could then be provided with an json-ld context:

{
    "@context": [
        {
          	"@version": 1.1,
            "wiki": "https://wiki-dev.open-semantic-lab.org/id/",
          	"Property": {"@id": "wiki:Property-3A", "@prefix": true},
          	"@vocab": "https://wiki-dev.open-semantic-lab.org/id/Property-3A",
            "myproperty": "Property:MyProperty",
            "myproperty2": "wiki:Property-3AMyProperty",
          	"myproperty3": "MyProperty",
          	"Item": {"@id": "wiki:Item-3A", "@prefix": true},
          	"myObjectProperty": {"@id": "Property:MyObjectProperty", "@type": "@id"}
        }
    ],
  	"myproperty": "Works by using '@prefix': true (preferred)",
  	"myproperty2": "Works by using 'wiki' prefix with terminating '/'",
  	"myproperty3": "Works by using '@vocab'",
  	"myObjectProperty": "Item:123456"
}

Currently there seems no way to express that a property has two ids (e. g. with "label": {"@id": ["property:HasLabel", "skos:prefLabel"]}): https://github.com/json-ld/json-ld.org/issues/160 As a workaround, an additional context notation is provided: <property>* pointing to a list of additional "@id" mappings:

{
    "@context": [
        {
            "@version": 1.1,
            "skos": "https://www.w3.org/TR/skos-reference/",
            "wiki": "https://wiki-dev.open-semantic-lab.org/id/",
          	"Property": {"@id": "wiki:Property-3A", "@prefix": true},
            "label": "skos:prefLabel",
            "label*": "Property:HasLabel",
            "label**": "Property:Display_title_of"
        }
    ],
  	"label": "Maps externally to skos:prefLabel and internally to Property:HasLabel"
}

OSW allows mapping to external (<any_prefix>:<property>) and internal vocabs (Property:<property>). Please note that properties mapped to an external vocab are currently not available in Semantic MediaWiki and the related query interfaces. Using the * notation it is possible to map to both external vocab  ("property": "<any_prefix>:<property>") and internal ("property*": "Property:<property>", "property**": "Property:<another_property>").

Object Properties and Data / Annotation Properties

Properties default to data / annotation properties (value is a literal). Object properties (value is an identifier/reference to another object) can by defined by adding "@type": "@id".

Subobjects

If the value of a mapped property is an object (after expanding all eval_templates), it will get stored as a smw subobject with an id derivated from the field uuid, a display title from mapped Property:HasLabel, Property:HasName or Property:Display title of (fallback values of keywordslabel or name or the schema title of the property pointing to the object) and a category from type (if provided). Subobjects also support JSON-LD @reverse notation, allowing to store properties pointing from the subobject to the superordinated or root object.

Example: can be selected with [[MyObjectProperty.MyProperty::myvalue]]

{
    "@context": [
        {
          	"@version": 1.1,
            "wiki": "https://wiki-dev.open-semantic-lab.org/id/",
          	"Property": {"@id": "wiki:Property-3A", "@prefix": true},
            "myproperty": "Property:MyProperty",
          	"Item": {"@id": "wiki:Item-3A", "@prefix": true},
          	"myObjectProperty": {"@id": "Property:MyObjectProperty", "@type": "@id"}
        }
    ],
  	"myObjectProperty": {
  	    "uuid": "2ea5b605-c91f-4e5a-9559-3dff79fdd4a5",
  	    "name": "MySubobject",
  	    "myproperty": "myvalue"
  	}
}

Labels and i18n

i18n language keys can be embedded in to an label object to create a language tagged string

{
    "@context": [
        {
          	"@version": 1.1,
            "skos": "https://www.w3.org/TR/skos-reference/",
          	"label": {"@id": "skos:prefLabel", "@container": "@language"},
          	"label2": {"@id": "skos:prefLabel"},
          	"label_text": {"@id": "@value"},
          	"label_lang_key": {"@id": "@language"}
        }
    ],
  	"label": {"en": "'Text' gets transformed to 'Text@en' by applying @container"},
  	"label2": {"label_text": "'Text' gets transformed to 'Text@de' by subkeys @id's", "label_lang_key": "de"}
}

Ontology term import/export

Existing ontology terms can be imported/exported via json-ld directly or ttl by defining the corresponding context, e. g. for EMMO-Terms: [7]

Matching external vocabularies and ontologies

As explained above, JSON-LD's @context allows to map properties to external vocabularies and ontologies.

In order to map classes and instances, additional annotation properties are provided:

• rdf_type - stating this entity is instance of an additional rdf class, see also https://schema.org/additionalType

• exact_ontology_match - stating an exact match, expressed by mapping to owl:sameAs | owl:equivalentClass | owl:equivalentProperty (see below) and skos:exactMatch externally, as well as internally to Property:Equivalent_URI and Property:HasExactOntologyMatch
• close_ontology_match - stating a close exact match, expressed by mapping to skos:closeMatch externally, as well as internally to Property:Equivalent_URI and Property:HasCloseOntologyMatch

This properties were originally available via a Characteristic type, called Ontology related, that can be mixed in by inheritance via an allOf in the respective schema. However, they are now integrated in the common Category:Entity for general availability.

rdf_type - Asserting additional types on instances

rdf_type has direct implication on the type system. The value must be a full IRI, e.g. https://schema.org/Person. Defined in Category:Entity it states additional RDF types for an Entity, which are directly applied.

rdf_type is mapped to rdfs:type, implying that an Item has additional RDF types, as stated by the JSON data on this property. A JSON-LD export of the JSON-data of this "Item" will contain a respective @type entry.

Ontology annotation - annotating conceptual proximity of an instance or class

To provide an annotation, e.g. to state that an Entity (Item or Category) matches a concept within an external ontology (closely), we have two properties exact_ontology_match and close_ontology_match.

The value must be a full IRI, e.g. https://schema.org/Person

While the meaning of close_ontology_match is constantly defined as stated above, the @context mapping of exact_ontology_match differs depending on the inheriting Category (Class) Schema:

Category:Entity

Abstract definition of the property.

Category:Item

Definition of the property for instances of the class (category) or its subclasses = Entities within the Item namespace.

exact_ontology_match is here mapped to owl:sameAs, implying that an Item has the same meaning as an external concept.

Category:Category (Class)

Definition of the property for instances of the class Category (Class) or its subclasses = Entities within the Category namespace, which themselves are categories.

exact_ontology_match maps to owl:equivalentClass, thereby stating that this Category is a concept equivalent to a class defined in an external vocabulary. Note: Instances of this class or category will only contain the additional @type if additional reasoning was applied by the export algorithm.

Category:Property

Definition of the property for instances of the class Property or its subclasses = Entities within the Property namespace, which are Semantic MediaWiki properties.

exact_ontology_match maps to owl:equivalentProperty, implying that a Property is equivalent to a property in an external vocabulary, e.g. https://schema.org/address which is an attribute of https://schema.org/Person.

Examples

Asserting equivalent class

The Category Person has a property exact_ontology_match with value https://schema.org/Person thereby stating that this concept is equivalent to the concept Person in schema.org.

Annotating equivalent instance

The instance of Quantity Unit "kilo gram" can state that it is equivalent to https://qudt.org/vocab/unit/KiloGM.

Recursive Parsing

Module:Category

Called from Category:<UUID>@template

1. Synchonize Category:<UUID>@jsondata.subclass_of with Category:<UUID>@jsonschema.allOf
2. Expand Category:Category@header_template with jsondata parameters
3. Render Category:<UUID>@main
4. Expand Category:Category@footer_template with jsondata parameters

Module:Entity

Called from item@template, item = Item:<UUID>

Recursion

1. For each Item:<UUID>@jsondata.osl_category as category:
   1. For each category@jsondata.osl_category or category@jsonschema.allOf as supercategory:
      1. For each supercategory@jsondata.osl_category or supercategory@jsonschema.allOf as supersupercategory:
         1. ...
      2. Expand supercategory@header_template with item@jsondata parameters. Fallback: Render infobox
      3. Expand supercategory@data_template with item.jsondata parameters. Fallback: Use Json-LD mapping within category:jsonschema
   2. If category@header_template: Expand category@header_template with item@jsondata parameters
   3. Else: Render infobox with all attribute-value pairs
   4. Expand category@data_template with item.jsondata parameters. Fallback: Use Json-LD mapping within category:jsonschema
2. Render item@main
3. footer...

Data Storing

1. template specified: use template
2. category specified:
   1. category@data_template specified: use data_template
   2. Use Json-LD mapping
      1. mapping specified: Store semantic property
         1. Literal value: store value
         2. Object value
            1. Property has type text/code: Store json string
            2. osl_category / osl_template specifided: see below
      2. Don't store semantic property

Nested objects within item@jsondata are handled

• osl_category: same handling as the root object, but:
  • Rendering with category@header_template. Fallback: Nested info box
  • Data storing with category@data_template. Fallback: Creating a subobject with Json-LD mapping + (inverse) semantic relation to the root object
• osl_template: expand the template, return value is asigned to the property

Python Code Generation

see https://github.com/OpenSemanticLab/osw-python

Statement

PCB contains 10% +/- 1% Lead and Gold

s	p/s	o/p/s	o/p	o...
PCB	contains	Lead
	contains	HasMassConcentration	10%
		HasMassConcentration	HasPrecision	1%
PCB	contains	Gold

File Handling

Copy-Policy

drop: do not copy the file

copy: copy the file and store the reference to it

copy-ref: store the referece to the original file

ask-on-edit: store the reference but ask the user to copy the original file when he tries to edit it (current_page != creation_page)

Meta-Data

HasProject=project inherit: permissions from project

HasCreationPage=creation_page: wiki page within this file was created

HasEditPage=edit_page: wiki page within this file was edited

HasCreator=creator: initial creator of the file

HasEditor=editor: editors of the file

Links

• https://tdan.com/knowledge-graphs-vs-property-graphs-part-ii/27271
• https://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Lehre/WS_2011-2012/SemWebGrundlagen/v03_handout.pdf

Graph

QR Code

Attachments

• 

  Schema diagram

• 

  meta-schema

• 

  diagram-classvars

• 

  OSW Introduction technology stack

Description:

📎 Select files (or drop them here)... 📷 Camera

jsondata

type	"Category:OSW92cc6b1a2e6b4bb7bad470dfdcfdaf26"
uuid	"ab674d66-3a5b-472f-838d-8e1eb43e6784"
label	text "OSW Schema" lang "en"
description	text "Documentation about to OSW data schema" lang "en"
name	"OswSchema"
attachments	"File:OSW2f275e3441c84f63a6cbee2861c488f2.drawio.svg" "File:OSW49d68bb7a5de413ba1077bc5f459a766.drawio.svg" "File:OSW61f1999ee6d145c9b76fb55d02578ce5.drawio.svg" "File:OSW95a74be1e22d4b6e9e4f836127d5915a.drawio.svg"