递归xml解析功能未按预期工作
[英]recursive xml-parsing function not working as intended
问题描述
I'm trying to parse an XML document and use the data to build a (simpler) json object of this form: 
我正在尝试解析XML文档并使用数据来构建这种形式的（简单）json对象：
{id: '1', name: 'content-types', children: [{id: '2', name: 'requirements': children: [... and so on ...]]}
My XML has nodes that look like the following (I've only included one -- they can be arbitrarily nested): 我的XML具有如下所示的节点（我仅包括其中一个-它们可以任意嵌套）：
<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head/>
<body class="taxonomies">
<div class="taxonomy">
<span class="id">3484069771</span>
<span class="name">Content Types</span>
<span class="locale">en</span>
<div class="concepts">
<div class="concept">
<span class="id">3484058507</span>
<span class="name">Promotional Publications</span>
<div class="concepts">
<div class="concept">
<span class="id">3551765771</span>
<span class="name">Datasheets</span>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
I use the following code to build a JSON tree from the XML: 我使用以下代码从XML构建JSON树：
buildConceptTree: function(xml){
const doc = new dom().parseFromString(xml)
var tree = []
var selector = "//*[@class='taxonomies']"
var count = 0 // this should keep track of the depth of the node being used
function recurse(s, odd){
var nodes
console.log(count)
console.log(s)
var arr = []
nodes = xpath.select(s, doc)
nodes.forEach(node => {
try {
var children = node.childNodes
var keys = Object.keys(children).filter(x => {return Number(x)})
keys.forEach(key => {
var child = children[key]
console.log('child is: ')
console.log(child)
var obj = {}
var grandchildren = child.childNodes
var grandkeys = Object.keys(grandchildren).filter(x => {return Number(x)})
grandkeys.forEach(gk => {
var gc = grandchildren[gk]
try {
var nodevalue = gc['attributes'][0]['nodeValue']
switch(nodevalue){
case 'id':
obj['id'] = gc['textContent']
case 'name':
obj['name'] = gc['textContent']
case 'concepts':
count++
var rx = /taxonomy/
if(!rx.test(s)){
s = s+"/*[@class='taxonomy']"
}
else{
s = s
}
if (!odd){
s += "/*[@class='concepts']"
}
else {
s += "/*[@class='concept']"
}
odd = !odd
obj['children'] = recurse(s, odd)
}
}
catch(e){
}
})
arr.push(obj)
})
}
catch(e){
}
})
return arr
}
var tree = recurse(selector, false)
return tree
},
As it stands, this function produces something like the JSON form I mentioned, but with many missing nodes. 就目前而言，此函数会产生类似于我提到的JSON形式的内容，但是缺少许多节点。
Also, it seems that my recursive function is not terminating in a simplest case as it recurs along deeper branches of the xml tree. 另外，似乎我的递归函数并没有在最简单的情况下终止，因为它沿着xml树的更深的分支递归。 I get the following logged in the console (for example), but there are no nodes that are 191 degrees deep: 我在控制台中记录了以下内容（例如），但是没有深度为191度的节点：
191
parser.js?d3c4:83 //*[@class='taxonomies']/*[@class='taxonomy']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']/*[@class='concept']/*[@class='concepts']
parser.js?d3c4:92 child is:
Can anyone help me figure out how to change this function to make it get the data I want? 谁能帮助我找出如何更改此功能以使其获取所需的数据？
1 个解决方案
解决方案1
1 已采纳 2018-08-23 15:48:44
I might've missed some requirements, but the the issue seems less complicated once you stop looping over all elements and start querying the exact elements you expect: 我可能已经错过了一些要求，但是一旦停止循环浏览所有元素并开始查询所需的确切元素，该问题似乎就不那么复杂了：
// Parse the xml string to a document const parser = new DOMParser(); const xmlDoc = parser.parseFromString( getXML(), "text/xml" ); // The main logic to go from an xml element to an object const parseTaxonomy = (taxonomy, id = 1) => ({ id, name: taxonomy.querySelector(".name") .innerText .toLowerCase() .replace(/\\s/g, "-"), children: Array.from( (taxonomy.querySelector(".concepts") || { children: [] }) .children ).map(t => parseTaxonomy(t, ++id)) // Note the ++ }); // Run on the first taxonomy // If the top level contains multiple elements, use .map console.log( parseTaxonomy( xmlDoc.querySelector(".taxonomy") ) ); // The data function getXML() { return `<?xml version="1.0" encoding="utf-8"?> <html xmlns="http://www.w3.org/1999/xhtml"> <head/> <body class="taxonomies"> <div class="taxonomy"> <span class="id">3484069771</span> <span class="name">Content Types</span> <span class="locale">en</span> <div class="concepts"> <div class="concept"> <span class="id">3484058507</span> <span class="name">Promotional Publications</span> <div class="concepts"> <div class="concept"> <span class="id">3551765771</span> <span class="name">Datasheets</span> </div> </div> </div> </div> </div> </body> </html>`; };
Note: I changed the part in which you put the comment because the comment wasn't closed and I expected it to have another wrapper around the child taxonomies. 注意：我更改了您放置评论的部分，因为该评论尚未关闭，并且我希望它在子分类法周围有另一个包装。
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