as3 xml检查元素是否存在

Question

我想检查每个子节点中是否存在此结构中的元素.问题是孩子们没有相同的名字(产品,预包装),我不想改变订单.另外,我无法更改XML结构.

<items>
    <product>
        <resourceImages>
            <image />
        </resourceImages>
    </product>
    <product>
        <resourceImages>
            <image />
        </resourceImages>
    </product>
    <prepack>
        <resourceImages />
    </prepack>
    <product>
        <resourceImages>
            <image />
        </resourceImages>
    </product>
    <prepack>
        <resourceImages />
    </prepack>
</items>

Answer 1

看来有两种方法,但使用undefined的检查似乎更可取.

if (item.image.length() > 0)

要么

if (item.image != undefined)

但请注意,无论节点是否存在,这始终都会为true.

if (item.image)

考虑到未定义的检查,这很奇怪.

Answer 2

像这样？

for each(var item : XML in xmlData.children())
{
    var hasImages : Boolean = (item.resourceImages.children().length() > 0);

    if(hasImages)
        trace("item has images")
}

Answer 3

还取决于你的第一个循环,但你也可以检查节点是否undefined:

var xml:XML=<items>
    <product>
        <resourceImages>
            <image />
        </resourceImages>
    </product>
    <product>
        <resourceImages>
            <image />
        </resourceImages>
    </product>
    <prepack>
        <resourceImages />
    </prepack>
    <product>
        <resourceImages>
            <image />
            <image />
        </resourceImages>
    </product>
    <prepack>
        <resourceImages />
    </prepack>
</items>;

//loop on all all resourceImage node
for each (var resourceImageXML:XML in xml..resourceImages){
    // and check if node if defined
    if (resourceImageXML.image != undefined) {
        // ok node have image
    }
}