# SPARQL-Results+XML Parse
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A utility package that allows you to parse [SPARQL XML](https://www.w3.org/TR/rdf-sparql-XMLres/) results
in a convenient [RDF/JS](http://rdf.js.org/)-based datastructure.
For example, the following SPARQL XML result can be converted as follows:
In:
```json
http://example.org/book/book1http://example.org/book/book2http://example.org/book/book3http://example.org/book/book4http://example.org/book/book5http://example.org/bobhttp://example.org/name
```
Out:
```javascript
[
{ '?book': namedNode('http://example.org/book/book1') },
{ '?book': namedNode('http://example.org/book/book2') },
{ '?book': namedNode('http://example.org/book/book3') },
{ '?book': namedNode('http://example.org/book/book4') },
{ '?book': namedNode('http://example.org/book/book5') },
{ '?book': quad(namedNode('http://example.org/bob'), namedNode('http://example.org/name'), literal('Bob', namedNode('http://example.org/Type'))) },
]
```
Where `namedNode` is an RDF/JS named node, `quad` is an RDF/JS quad/triple, and `literal` is an RDF/JS literal.
This library automatically converts all SPARQL XML result values to their respective RDFJS type.
## Usage
### Create a new parser
```javascript
import {SparqlXmlParser} from "sparqlxml-parse";
const sparqlXmlParser = new SparqlXmlParser();
```
Optionally, you can provide a settings object to the constructor with optional parameters:
```javascript
const sparqlXmlParser = new SparqlXmlParser({
dataFactory: dataFactory, // A custom RDFJS datafactory
prefixVariableQuestionMark: true, // If variable names in the output should be prefixed with '?', default is false.
});
```
### Convert a SPARQL XML response stream
If you have many query results, then a streaming-based approach
as provided by `sparqlXmlParser.parseXmlResultsStream` is ideal.
```javascript
const sparqlJsonResponseStream = streamifyString(`
http://example.org/book/book1`);
sparqlXmlParser.parseXmlResultsStream(sparqlJsonResponseStream)
.on('data', (bindings: IBindings) => console.log(bindings));
// This will output [ { '?book': namedNode('http://example.org/book/book1') } ]
```
Optionally, you can also retrieve the variables inside the `head`
as follows by listening to the `variables` event:
```javascript
sparqlXmlParser.parseXmlResultsStream(sparqlJsonResponseStream)
.on('variables', (variables: RDF.Variable[]) => console.log(variables))
.on('data', (bindings: IBindings) => { return; });
// This will output [ variable('book') ]
```
### Convert a SPARQL XML boolean response stream
```javascript
const sparqlJsonResponseStream = streamifyString(`
true`);
sparqlXmlParser.parseXmlBooleanStream(sparqlJsonResponseStream)
.then((result: boolean) => console.log(result));
// This will output true
```
## License
This software is written by [Ruben Taelman](http://rubensworks.net/).
This code is released under the [MIT license](http://opensource.org/licenses/MIT).