Parsing a string that contains xml like syntax

Question

I'm looking for a way to parse a string containing inline elements that can be picked up by javascript. An example.

Given the below parseable string:

"I have a <noun length="10" />

Is there any way to easily parse this string and understand that there is an object in that string called "noun" that contains a length property with a value of 10?

[XML parsing of a variable string in JavaScript](http://stackoverflow.com/questions/649614/xml-parsing-of-a-variable-string-in-javascript)? — blex, Jul 27 '14 at 20:32
".. but rather a string that –"? Do you want a non-DOM approach? — dcromley, Jul 27 '14 at 20:57
What is an "XML-like syntax"? HTML is 'XML-like', SGML language with enough `<` and `>` characters in is 'XML-like'. Without a clearer understanding of your syntax this is too broad to answer. — , Jul 28 '14 at 01:26

Mads Hansen · Accepted Answer · 2014-07-28T01:22:13.623

You need to ensure that your string is well-formed XML. In this case, you need to ensure that there is a document element.

An example of how you can wrap the value in a <doc> element and then parse and query for the attribute value:

function parseSnippet(snippet, xpathExpression) {
    var startDoc = "<doc>",
        endDoc = "</doc>",
        xml = startDoc + snippet + endDoc,
        xmlDoc;

    if (window.DOMParser) {
        parser = new DOMParser();
        xmlDoc = parser.parseFromString(xml, "text/xml");
    } else // Internet Explorer
    {
        xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
        xmlDoc.async = false;
        xmlDoc.loadXML(xml);
    }
    return xmlDoc;
}
var xmlDoc = parseSnippet('I have a <noun length="10" />');
var nounLength = document.evaluate('/doc/noun/@length', 
                                   xmlDoc, 
                                   null,
                                   XPathResult.FIRST_ORDERED_NODE_TYPE, 
                                   null).singleNodeValue.textContent;

alert("length: " + nounLength);

Below is the same concept, but leveraging jQuery and the parseXML() function:

function parseSnippet(snippet) {
    var startDoc = "<doc>",
        endDoc = "</doc>",
        xml = startDoc + snippet + endDoc,
        xmlDoc = $.parseXML( xml );

    return $( xmlDoc );   
}
var $length = parseSnippet('I have a <noun length="10" />')
              .find( "noun" ).attr("length");

console.log("length: "+ $length);

*"Unless a tag for a framework/library is also included, a pure JavaScript answer is expected."* — Felix Kling, Jul 28 '14 at 00:57

score -1 · Answer 2 · answered Jul 28 '14 at 01:03

-1

Would jquery work?

var a = $(string)
undefined
a.select("noun")
[
<noun attr="thing"></noun>
]
a.select("noun").attr("attr")
"thing"

answered Jul 28 '14 at 01:03

Blaskovicz

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Parsing a string that contains xml like syntax

2 Answers2