从节点中删除空属性并清空子节点 [英] Remove null attributes and empty children from Node
问题描述
我有一个节点，我想删除所有 null 属性，并在我将其写入文件之前递归地清空子项。我在下面的工作，但它似乎应该有一个内置的方法。我错过了什么？
I have a Node which I want to remove all null attributes and empty children from recursively before I write it to a file. What I have below works, but it seems like there should be a built in method for this. Have I missed something?
Node cleanNode(Node node) {
// Find null attributes
def attributesToRemove = []
for(e in node.attributes()) {
if(e.value == null) {
attributesToRemove.add(e.key)
}
}
// Remove null attributes
for(attribute in attributesToRemove) {
node.attributes().remove(attribute)
}
// Clean this node's children
for(child in node.children()) {
if(child instanceof Node) {
cleanNode(child)
}
}
// If node has no attributes, no children, and no text then discard it by setting it to null
if(!node.attributes() && !node.children() && !node.text()) {
node = null
}
node
}
推荐答案
r这样做，我知道...你可以让你的代码稍微小一些（并递归地删除空的孩子），如下所示：
There's not a build in method for doing this that I know of... You could get your code a little smaller (and recursively remove empty children) like so:
boolean cleanNode( Node node ) {
node.attributes().with { a ->
a.findAll { !it.value }.each { a.remove( it.key ) }
}
node.children().with { kids ->
kids.findAll { it instanceof Node ? !cleanNode( it ) : false }
.each { kids.remove( it ) }
}
node.attributes() || node.children() || node.text()
}
所以给了xml：
def xml = '''<root>
| <head>
| <item>
| <woo/>
| </item>
| </head>
| <body att=''>
| <h1 name='' title='title'>
| woo
| </h1>
| </body>
| <tail>
| <item>hi</item>
| </tail>
|</root>'''.stripMargin()
我们可以解析它并打印出来并打印出来：
We can parse it and clean it and print it out:
Node root = new XmlParser().parseText( xml )
cleanNode( root )
println XmlUtil.serialize( root )
给出：
<?xml version="1.0" encoding="UTF-8"?><root>
<body>
<h1 title="title">woo</h1>
</body>
<tail>
<item>hi</item>
</tail>
</root>
正如您所见，整个< head> block已被清除，因为它不包含任何信息。
As you can see, the whole <head> block has been cleaned as it contained no information.
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