Package Exports

graphy

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (graphy) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

graphy

Query linked-data graphs by abstracting away traditional JSON-LD interaction

Install

$ npm install --save graphy

Usage

Take the following graph:

@prefix ns: <vocab://ns/> .
@prefix color: <vocab://color/> .
@prefix plant: <vocab://plant/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ns:Banana
    a ns:Fruit ;
    ns:shape "curved"^^ns:Liberty ;
    ns:tastes "good"^^xsd:string ;
    ns:data 25 ;
    ns:class ns:Berry ;
    ns:appears color:Yellow ;
    plant:blossoms ns:YearRound ;
    ns:alias ns:Cavendish ;
    ns:alias ns:Naner ;
    ns:alias ns:Bananarama ;
    ns:stages (
        ns:FindSpace
        plant:Seed
        plant:Grow
        plant:Harvest
    ) ;
    ns:considered [
        a plant:Clone
    ]

Here, example.json is a JSON-LD file generated from the graph above:

var graphy = require('graphy');

var json_ld = require('./example.json');
var q_graph = graphy(json_ld);

// traverse the graph using namespace given by the prefix 'ns:'
q_graph.network('ns:', function(k_banana) {

    // get iri of node
    k_banana.$id; // 'Banana'
    k_banana['@id']; // 'vocab://ns/Banana'

    // get default `rdf:type` property of node
    k_banana.$type; // 'Fruit'
    k_banana['@type']; // 'vocab://ns/Fruit'

    // get value of a literal
    k_banana.shape(); // 'curved'
    k_banana.tastes(); // 'good'

    // get suffixed datatype of a literal
    k_banana.shape.$type; // 'Liberty'
    k_banana.tastes.$type; // undefined

    // get absolute datatype of a literal
    k_banana.shape['@type']; // 'vocab://ns/Liberty'
    k_banana.tastes['@type']; // 'http://www.w3.org/2001/XMLSchema#string'

    // get full SPARQL/TTL-compatible string representation of a literal
    k_banana.tastes['@full']; // '"good"^^<http://www.w3.org/2001/XMLSchema#string>'

    // change namespace to get suffixed datatype of literal
    k_banana.tastes.$('xsd:').$type; // 'string'

    // properties of an iri in same namespace
    k_banana.class(); // 'Berry'
    k_banana.class.$id; // 'Berry'
    k_banana.class['@id']; // 'vocab://ns/Berry'
    k_banana.class['@type']; // '@id'

    // properties of an iri in different namespace
    k_banana.appears(); // undefined
    k_banana.appears.$id; // undefined
    k_banana.appears['@id']; // 'vocab://color/Yellow'
    k_banana.appears['@type']; // '@id'
    k_banana.appears.$('color:').$id; // 'Yellow'

    // changing namespace
    k_banana.$('plant:').blossoms(); // undefined
    k_banana.$('plant:').blossoms.$id; // 'vocab://ns/YearRound'
    k_banana.$('plant:').blossoms.$('ns:').$id; // 'YearRound'

    // terse form: auto-prefixing (SPARQL & TTL compatible strings)
    k_banana.$terse(); // 'ns:Banana'
    k_banana.appears.$terse(); // 'color:Yellow'
    k_banana.tastes.$terse(); // '"good"^^xsd:string'
    k_banana.tastes.$terse.value(); // '"good"'
    k_banana.tastes.$terse.datatype(); // 'xsd:string'

    // type indicators
    k_banana.$is(); // 'node'
    k_banana.$is.node; // true

    // type indicators ..contd'
    k_banana.appears.$is(); // 'iri'
    k_banana.data.$is(); // 'literal'
    k_banana.stages.$is(); // 'collection'
    k_banana.considered.$is(); // 'blanknode'

    // type indicators ..contd'
    k_banana.$is.node; // true
    k_banana.appears.$is.iri; // true
    k_banana.data.$is.literal; // true
    k_banana.stages.$is.iri; // undefined
    k_banana.stages.$is.literal; // undefined
    k_banana.stages.$is.collection; // true
    k_banana.considered.$is.blanknode; // true

    // predicates with multiple objects
    k_banana.alias; // emits warning: 'more than one triple share the same predicate "ns:alias" with subject "ns:Banana"; By using '.alias', you are accessing any one of these triples arbitrarily'

    // ..contd'
    let a_items = k_banana('alias', function(k_alias) { // implicit `.map` callback
        return k_alias();
    });
    a_items; // ['Cavendish', 'Naner', 'Bananarama']

    // collections
    k_banana.stages().map(function(k_stage) {
        return k_stage.$id || k_stage.$('plant:').$id;
    }); // ['FindSpace', 'Seed', 'Grow', 'Harvest']

    // collections: implicit `.map`
    k_banana.stages(function(k_stage) { // implicit `.map` callback
        return k_stage.$id || k_stage.$('plant:').$id;
    }); // ['FindSpace', 'Seed', 'Grow', 'Harvest']
});

Iterating

for..in

for..of

RDF Collections

Calling a collection node as a function with no arguments will return the underlying array.

...

The returned array is the underlying array; mutating the returned object will also affect the underlying array

You can also iterate a collection node using for..of

for(let k_stage of k_banana.stages) {
    // ...
}

In order to be consistent with the graph, rdf collection properties are emulated on collection objects. So instead of accessing a collection's elements via Array's properties/methods, you can also use the rdf:first and rdf:rest properties:

let w_list = k_banana.stages.$('rdf:');

w_list.first.$('ns:').$id; // 'FindSpace'

w_list = w_list.rest;
w_list.first.$('plant:').$id; // 'Seed'

w_list = w_list.rest;
w_list.first.$('plant:').$id; // 'Grow'

w_list = w_list.rest;
w_list.first.$('plant:').$id; // 'Harvest'

w_list = w_list.rest;
w_list.$id; // 'nil'

// ------------ or in a loop ------------
let a_stages = [];
let w_list = k_banana.stages.$('rdf:');
while(w_list.$id !== 'nil') {
    a_stage.push(w_list.first.$('plant:').$id || w_list.first.$('ns:').$id);
    w_list = w_list.rest;
}
a_stages; // ['FindSpace', 'Seed', 'Grow', 'Harvest']

node.$(terse_namespace: string)

Returns a node that points to the same LD node but changes its namespace to the expanded version of the IRI given by terse_namespace. By chaining this call, you can change the namespace on the same line to access properties or iris by their suffix.

node.$terse()

Returns a string representation of the node in terse form. The string is both SPARQL and TTL compatible; it is prefixed by the longest matching URI available in the original JSON-LD context, unless the resulting suffix would contain invalid characters for a prefixed IRI in either SPARQL or TTL.

graphy

Package Exports

Readme

graphy

Install

Usage

Iterating

RDF Collections

node.$(terse_namespace: string)

node.$terse()

License