Sparnatural SPARQL query builder
Sparnatural is a visual SPARQL query builder written in Typescript.
It supports the creation of basic graph patterns with the selection of values with autocomplete search or dropdown lists. It can be configured through a JSON-LD or OWL configuration file (that can be edited in Protégé) that defines the classes and properties to be presented in the component.
You can play with online demos at http://sparnatural.eu#demos.
Getting Started
To get started :
- Read the following README;
- Read the documentation
- Look at how things work in sparnatural-demo-dbpedia;
- In particular look at how the specifications are written by looking at the source of
sparnatural-demo-dbpedia/index.html
- Adapt
sparnatural-demo-dbpedia/index.html
by changing the configuration and adapting the SPARQL endpoint URL;
Features
Query Structure
Basic query pattern
Select the type of entity to search...
... then select the type of the related entity.
In this case there is only one possible type of relation that can connect the 2 entities, so it gets selected automatically. Then select a value for the related entity, in this case in a dropdown list :
Congratulations, your first SPARQL query criteria is complete !
Now you can fetch the generated SPARQL query :
"WHERE"
This enables to navigate the graph :
"AND"
Combine criterias :
"OR"
Select multiple values for a criteria :
Values selection
Sparnatural offers currently 6 ways of selecting a value for a criteria : autocomplete field, dropdown list, simple string value, date range (year or date precision), date range with a search in a period name (e.g. "bronze age"), or no selection at all.
Autocomplete field
Dropdown list
Tree selector
Map selector
String value (text search)
Date range (year or date precision)
Date range with search in period name (chronocultural periods)
(this requires data from Perio.do, a gazeeter of periods for linking and visualizing data)
Boolean selection
No value selection
This is useful when a type a of entity is used only to navigate the graph, but without the ability to select an instance of these entities.
Multilingual
Sparnatural is multilingual and supports displaying labels of classes and properties in multiple languages.
Support for OPTIONAL and FILTER NOT EXISTS
Sparnatural supports the OPTIONAL
and FILTER NOT EXISTS {}
keywords applied to a whole "branch" of the query.
See here how to search for French Museums and the name of Italian painters they display, if any :
Support for SERVICE keyword
There is currently an experimental support for the SERVICE keyword for federated querying.
Limitations
No UNION or BIND, etc.
Sparnatural does not support the creation of UNION, BIND, etc...
SPARQL endpoint needs to be CORS-enabled
To send SPARQL queries to a service that is not hosted on the same domain name as the web page in which Sparnatural is included, the SPARQL endpoint needs to allow Cross-Origin Resource Sharing (CORS). But we have SPARQL proxies for those who are not, don't worry ;-)
Integration
Specification of classes and properties
The component is configurable using a an OWL configuration file editable in Protégé.. Look at the specification files of the demos to get an idea.
Alternatively one can also use a JSON(-LD) ontology file. A JSON(-LD) configuration file contains :
Class definition
{
"@id" : "http://dbpedia.org/ontology/Museum",
"@type" : "Class",
"label": [
{"@value" : "Museum", "@language" : "en"},
{"@value" : "Musée","@language" : "fr"}
],
"faIcon": "fas fa-university"
},
Property definitions with domains and ranges
{
"@id" : "http://dbpedia.org/ontology/museum",
"@type" : "ObjectProperty",
"subPropertyOf" : "sparnatural:AutocompleteProperty",
"label": [
{"@value" : "displayed at","@language" : "en"},
{"@value" : "exposée à ","@language" : "fr"}
],
"domain": "http://dbpedia.org/ontology/Artwork",
"range": "http://dbpedia.org/ontology/Museum",
"datasource" : "datasources:search_rdfslabel_bifcontains"
},
Using font-awesome icons
It is possible to directly use font-awesome icons in place of icons embedded in your application :
"faIcon": "fas fa-user",
How to integrate Sparnatural in a webpage
Look at this page in the documentation.
Map the query structure to a different graph structure
Map classes or properties in the config to a corresponding SPARQL property path or a corresponding class URI, using the sparqlString
JSON key, e.g. :
{
"@id" : "http://labs.sparna.fr/sparnatural-demo-dbpedia/onto#bornIn",
"@type" : "ObjectProperty",
...
"sparqlString": "<http://dbpedia.org/ontology/birthPlace>/<http://dbpedia.org/ontology/country>",
},
Then call expandSparql
on the sparnatural
instance by passing the original SPARQL query, to replace all mentions of original classes and properties URI with the corresponding SPARQL string :
queryString = sparnatural.expandSparql(queryString);