XML parsing from SPARQL endpoint with javascript ES6

es6_parsing_rdf_xml.md

XML parsing from SPARQL endpoint with javascript ES6

NodeList has no map method, forEach method, so it's boring to parsing xml type dataset in js.

if Chrome...

if Chrome forEach method is OK

elements = xmlRoot.querySelectorAll('result');
elements.forEach(function(x){
    var items = x.getElementsByTagName('binding')[0].getAttribute('name');
    console.log(items)
});

and (for .. of) is OK too.

elements = xmlRoot.querySelectorAll('result');
for(let x of elements){
    let items = x.getElementsByTagName('binding')[0].getAttribute('name');
    console.log(items)
}

Array.prototype.forEach.call

this method is OK with Chrome and safari.

Array.prototype.forEach.call(xmlRoot.querySelectorAll('result'), function(x){console.log(x.getElementsByTagName('binding'))});

it's seems better to use arrow function as callback, but safari does not corresponde to this method.

Array.from

this ES6 method is OK with Chrome and safari too.

items = Array.from(xmlRoot.querySelectorAll('result'), function(x){return  x.getElementsByTagName('binding')});
console.log(items)

ES6 xml parser sample for SPARQL endpoint

// 選択した遺伝子のgene idでrefexの情報を取得
function get_refex_info(gid){
    var qs = encodeURIComponent(query_refex_info(gid));
    var q = endpoint + "?query=" + qs;
    d3.xml(q, function (error, xmlRoot) {
        items = Array.from(xmlRoot.querySelectorAll('result'), function(x){return x2obj(x)});
        console.log(items[0])
    })
}

// NodeListをオブジェクトに変換
function x2obj(x) {
    var item = {};
    item['refex'] =  x.querySelectorAll('[name=refex]').item(0).textContent;
    item['sample'] = x.querySelectorAll('[name=sample]').item(0).textContent;
    item['organism'] = x.querySelectorAll('[name=organism]').item(0).textContent;
    item['exp_val'] = x.querySelectorAll('[name=expression_value]').item(0).textContent;
    item['sample_cat'] = x.querySelectorAll('[name=sample_category]').item(0).textContent;
    return item
}

reference