How to read CDATA from an XML file in Node Sax

问题

I have an XML structure like this:

<?xml version="1.0" encoding="utf-8"?>
<videos>
    <video>
        <id>47288</id>
        <thumbs>
            <thumb><![CDATA[http://foo.com/bar.jpg]]></thumb>
        </thumbs>
        <link><![CDATA[http://foo.com/bar.html]]></link>
        <title><![CDATA[Sample Title Here]]></title>
        <categories>
            <category><![CDATA[Cat1]]></category>
            <category><![CDATA[Cat2]]></category>
        </categories>
        <tags>
            <tag><![CDATA[Tag1]]></tag>
            <tag><![CDATA[Tag2]]></tag>
            <tag><![CDATA[Tag3]]></tag>
            <tag><![CDATA[Tag4]]></tag>
            <tag><![CDATA[Tag5]]></tag>
            <tag><![CDATA[Tag6]]></tag>
        </tags>
        <duration><![CDATA[9:57]]></duration>
        <pubDate><![CDATA[2013-12-17]]></pubDate>
    </video>
    // insert 200,000 more <video> entries here

No idea why this is all written as CDATA but there's not much I can do about it, it's the data I've been given. My code to read this massive (1.5gb) XML file is to stream it using fs to sax then to saxpath, like so:

var saxpath = require('saxpath')
var fs = require('fs')
var sax = require('sax')
var parseString = require('xml2js').parseString;
var util = require('util');

var saxParser = sax.createStream(true)
var streamer = new saxpath.SaXPath(saxParser, '/videos/video')

streamer.on('match', function(xml) {
    console.log(xml);
    parseString(xml, function (err, result) {
        var json1 = JSON.stringify(result);
        var json = JSON.parse(json1);
        console.log(util.inspect(json, false, null));
    });

});

fs.createReadStream('./xml/big_data_file.xml').pipe(saxParser)

However, when I get to the console.log(xml), it shows this:

<video>
    <id>620339</id>
    <thumbs>
        <thumb></thumb>
    </thumbs>
    <link></link>
    <title></title>
    <categories>
        <category></category>
        <category></category>
    </categories>
    <tags>
        <tag></tag>
        <tag></tag>
        <tag></tag>
        <tag></tag>
        <tag></tag>
        <tag></tag>
        <tag></tag>
    </tags>
    <duration></duration>
    <pubDate></pubDate>
</video>

No data inside whatsoever. There's no mention of CDATA in the Saxpath Docs, although I'm not sure if this is an issue with Saxpath or Sax itself.

Any ideas how I can remedy this?

Cheers!

回答1:

That's a limitation of SaXPath 0.5.4, v0.5.5 that was just pushed to npm now handles CDATA (see commit) as you would expect.

With the exact same code and the last version of SaXPath:

<video>
        <id>47288</id>
        <thumbs>
            <thumb><![CDATA[http://foo.com/bar.jpg]]></thumb>
        </thumbs>
        <link><![CDATA[http://foo.com/bar.html]]></link>
        <title><![CDATA[Sample Title Here]]></title>
        <categories>
            <category><![CDATA[Cat1]]></category>
            <category><![CDATA[Cat2]]></category>
        </categories>
        <tags>
            <tag><![CDATA[Tag1]]></tag>
            <tag><![CDATA[Tag2]]></tag>
            <tag><![CDATA[Tag3]]></tag>
            <tag><![CDATA[Tag4]]></tag>
            <tag><![CDATA[Tag5]]></tag>
            <tag><![CDATA[Tag6]]></tag>
        </tags>
        <duration><![CDATA[9:57]]></duration>
        <pubDate><![CDATA[2013-12-17]]></pubDate>
</video>

And the parsed result of xml2js:

{ video: 
   { id: [ '47288' ],
     thumbs: [ { thumb: [ 'http://foo.com/bar.jpg' ] } ],
     link: [ 'http://foo.com/bar.html' ],
     title: [ 'Sample Title Here' ],
     categories: [ { category: [ 'Cat1', 'Cat2' ] } ],
     tags: [ { tag: [ 'Tag1', 'Tag2', 'Tag3', 'Tag4', 'Tag5', 'Tag6' ] } ],
     duration: [ '9:57' ],
     pubDate: [ '2013-12-17' ] } }

来源：https://stackoverflow.com/questions/20673911/how-to-read-cdata-from-an-xml-file-in-node-sax

标签

javascript

xml

node.js

sax

cdata